From alan.gauld at btinternet.com  Mon Dec  1 01:57:04 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 1 Dec 2008 00:57:04 -0000
Subject: [Tutor] Reading gzip files
References: <COL103-DS25A7FCECB9945C37E775BAA3060@phx.gbl>
Message-ID: <ggvcov$eio$1@ger.gmane.org>


"Dinesh B Vadhia" <dineshbvadhia at hotmail.com> wrote

> I'm reading gzip files and writing the content out to a text file 
> line by line.
>  File "C:\Python25\lib\gzip.py", line 275, in _read
>    self._read_eof()
>  File "C:\Python25\lib\gzip.py", line 311, in _read_eof
>    raise IOError, "CRC check failed"
> IOError: CRC check failed
>
> I've checked the Python docs and online but cannot find a
> solution to the problem.  Thanks.

At great risk of stating the obvious but have you actually checked
that the CRC of the gzipped file is correct? Does the problem only
happen with this file or with all gzipped files?

And are the files actually zipped by gzip or by some other
"compatible" program? If other does it work for genuine
gzipped files?

Just some ideas to play with.

Alan G 



From david at abbottdavid.com  Mon Dec  1 02:17:00 2008
From: david at abbottdavid.com (David)
Date: Sun, 30 Nov 2008 20:17:00 -0500
Subject: [Tutor] Reading gzip files
In-Reply-To: <COL103-DS25A7FCECB9945C37E775BAA3060@phx.gbl>
References: <COL103-DS25A7FCECB9945C37E775BAA3060@phx.gbl>
Message-ID: <49333B0C.7020300@abbottdavid.com>

Dinesh B Vadhia wrote:
> I'm reading gzip files and writing the content out to a text file line
> by line.  The code is simply:
>  
> import gzip
> list_zipfiles  = dircache.listdir(zipfolder)
> writefile = "out_file.txt"
> fw = open(writefile, 'w')
>  
> for ziparchive in list_zipfiles:
>     zfile = gzip.GzipFile(zipfolder + ziparchive, "r")
>     for line in zfile:
>         fw.write(line)
>     zfile.close()
> fw.close()
I am learning also. I came up with this;
#!/usr/bin/python
import tarfile
tFile = tarfile.open("/home/david/zip_files/zip.tar.gz", "r")
for f in tFile.getnames():
    print f
    tFile.close()
#fname = "out.txt"
#fobj = open(fname, 'w')
#for line in f:
#    fobj.write(line + '/n')
#tFile.close()
#fobj.close()

My problem is I can not figure out how to write to the file with new
lines, as you can see my attempts at the bottom. This works fine in Linux;
./py_list_zip.py >> out.txt

but I want to learn how to do it within python, plus to understand.

any hints :)

thanks
-david



-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com


From david at abbottdavid.com  Mon Dec  1 02:35:12 2008
From: david at abbottdavid.com (David)
Date: Sun, 30 Nov 2008 20:35:12 -0500
Subject: [Tutor] Reading gzip files
In-Reply-To: <49333B0C.7020300@abbottdavid.com>
References: <COL103-DS25A7FCECB9945C37E775BAA3060@phx.gbl>
	<49333B0C.7020300@abbottdavid.com>
Message-ID: <49333F50.7000609@abbottdavid.com>

David wrote:

> #!/usr/bin/python
> import tarfile
> tFile = tarfile.open("/home/david/zip_files/zip.tar.gz", "r")
> for f in tFile.getnames():
>     print f
>     tFile.close()
> #fname = "out.txt"
> #fobj = open(fname, 'w')
> #for line in f:
> #    fobj.write(line + '/n')
> #tFile.close()
> #fobj.close()
> 
> My problem is I can not figure out how to write to the file with new
> lines, as you can see my attempts at the bottom. This works fine in Linux;
> ./py_list_zip.py >> out.txt
> 
> but I want to learn how to do it within python, plus to understand.
> 
> any hints :)
> 
> thanks
> -david
> 
> 
> 
oops should have been;
    fobj.write(line + '\n')
still does not work, now here is the output from the print statment;
zip/
zip/py_database.py
zip/print_time.py
and out.txt
z
i
p
/
p
r
i
n
t
_
t
i
m
e
.
p
y

-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com


From dineshbvadhia at hotmail.com  Mon Dec  1 03:42:04 2008
From: dineshbvadhia at hotmail.com (Dinesh B Vadhia)
Date: Sun, 30 Nov 2008 18:42:04 -0800
Subject: [Tutor] Reading gzip files
Message-ID: <COL103-DS19E268FE36CDC89F9135A3A3010@phx.gbl>

Hi Alan

A bunch of gzipped files are read with the majority working but a few don't.  I don't know if these files were originally zipped with gzip but I'd guess that they were.

Strangely, for the files that don't work I can read/print the file almost to the end and then it falls over with the CRC error.

Dinesh



--------------------------------------------------------------------------------

Message: 5
Date: Mon, 1 Dec 2008 00:57:04 -0000
From: "Alan Gauld" <alan.gauld at btinternet.com>
Subject: Re: [Tutor] Reading gzip files
To: tutor at python.org
Message-ID: <ggvcov$eio$1 at ger.gmane.org>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original


"Dinesh B Vadhia" <dineshbvadhia at hotmail.com> wrote

> I'm reading gzip files and writing the content out to a text file 
> line by line.
>  File "C:\Python25\lib\gzip.py", line 275, in _read
>    self._read_eof()
>  File "C:\Python25\lib\gzip.py", line 311, in _read_eof
>    raise IOError, "CRC check failed"
> IOError: CRC check failed
>
> I've checked the Python docs and online but cannot find a
> solution to the problem.  Thanks.

At great risk of stating the obvious but have you actually checked
that the CRC of the gzipped file is correct? Does the problem only
happen with this file or with all gzipped files?

And are the files actually zipped by gzip or by some other
"compatible" program? If other does it work for genuine
gzipped files?

Just some ideas to play with.

Alan G 
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From kent37 at tds.net  Mon Dec  1 12:35:08 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 1 Dec 2008 06:35:08 -0500
Subject: [Tutor] Reading gzip files
In-Reply-To: <COL103-DS19E268FE36CDC89F9135A3A3010@phx.gbl>
References: <COL103-DS19E268FE36CDC89F9135A3A3010@phx.gbl>
Message-ID: <1c2a2c590812010335h6406da25o2db597ae38f25433@mail.gmail.com>

On Sun, Nov 30, 2008 at 9:42 PM, Dinesh B Vadhia
<dineshbvadhia at hotmail.com> wrote:

> Strangely, for the files that don't work I can read/print the file almost to
> the end and then it falls over with the CRC error.

That's because the CRC isn't checked until after the file is read; as
you can see from the traceback, the error is in _read_eof(). You could
put a print statement or breakpoint in that function to get more
information about the failure.

Kent

From denis.spir at free.fr  Mon Dec  1 13:35:27 2008
From: denis.spir at free.fr (spir)
Date: Mon, 01 Dec 2008 13:35:27 +0100
Subject: [Tutor] attribute of built-in type
In-Reply-To: <1c2a2c590811300520y3a69329fp1a042461c46d640b@mail.gmail.com>
References: <49305ADF.7090706@free.fr>	
	<1c2a2c590811281418x5f46b1ddrbe96e2be9bf7900b@mail.gmail.com>	
	<49307855.9090900@free.fr>	
	<1c2a2c590811290529n3a46150exc07a647e41f339dc@mail.gmail.com>	
	<4931BD94.9000809@free.fr>
	<1c2a2c590811300520y3a69329fp1a042461c46d640b@mail.gmail.com>
Message-ID: <4933DA0F.2030207@free.fr>

Kent Johnson a ?crit :

[...big snip...]

 > Do you know that you can probably just assign a __name__ attribute to
 > the objects? Or name, or whatever you like?
 >
 > In [13]: class Foo(object): pass
 >    ....:
 >
 > In [14]: f=Foo()
 >
 > In [15]: f.name
 > ---------------------------------------------------------------------------
 > AttributeError                            Traceback (most recent call last)
 >
 > /Users/kent/<ipython console> in <module>()
 >
 > AttributeError: 'Foo' object has no attribute 'name'
 >
 > In [16]: f.name = 'f'
 >
 > In [17]: f.name
 > Out[17]: 'f'
 >
 > This will work for custom objects that do not have a __slots__
 > attribute. Perhaps you could wrap the creation of the objects in a
 > function that gives them a name?

Exactly. I presently use a tool func (actually, a Classmethod) that executes 
this (pseudocode):
def set_names(scope):
	for name,obj in scope.__dict__.items():
		# exclude not_to_be_named objects of the scope
		if name_has_the_proper_form:
			# 'name' attr already used for other purpose
			obj.id = name

Which works. I will use this method if I cannot find a way to let the objects 
natively have __name__ attributes. Conceptually , it is not the same thing -- 
at least for me. That a class of objects has such an attribute may be seen as 
an interface characteristics (comparable to 'iterable' or 'ordered') that could 
be inherited. If I want a class to define/construct ordered containers, I will 
simply let it inherit list's interface. The facts that python sets __name__ 
attributes at a low level (as you explain below) and that workarounds are not 
satisfying, both confirm that this is a fondamental interface charasteristics, 
not a superficial one.

Also, I need a name format rule to distinguish to_be_named from not_to_be_named 
objects. This is not a big issue, as this rule has only to be followed inside a 
specific scope. But maybe you understand that I do not find this conceptually 
/satisfying/. A logical feature that should not depend on such a random detail, 
rather it should be a basic property. Imagine a case where you would need to 
give objects characteristics such as iterable or ordered (or mutable / 
immutable!), by implementing the proper __xxx__ methods, based on the fact that 
their name has this or that format. Which may happen if such characteristics 
could not be inherited in python.

[...smaller snip...]

 >> It is an illustration of what i'm trying to do: let a class inherit from
 >> 'function' so that its instances get a __name__. This wouldn't be a harmful
 >> overload I guess, as these objects have a __call__ method anyway (the reason
 >> why I chose 'function').
 >
 > I doubt this would do what you want. AFAICT the function name is
 > assigned by the compiler, not by the function constructor. (That is a
 > bit of oversimplification but close enough. I think the compiler
 > creates a code object, passing its name to the constructor; when a
 > function object is wrapped around the code object, it pulls its name
 > from the code object.)

This let me play a bit further with functions. The following confirms both that 
  __name__ is a very low-level attribute, and that it lies in the code itself:
=============================
import types ; Function = types.FunctionType

def typ(obj): return obj.__class__.__name__
def f():pass
g = f
print id(f)
print "%s: %s at %s \n" % ( g.__name__,typ(g),id(g) )

print dir(f)
cod = g.func_code
print "cod is a '%s' object\n" % typ(cod)

h = Function(cod,{})
print "%s: %s at %s \n" % ( h.__name__,typ(h),id(h) )

==>

10464752
f: function at 10464752

['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__get__', 
'__getattribute__', '__hash__', '__init__', '__module__', '__name__', 
'__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', 
'func_closure', 'func_code', 'func_defaults', 'func_dict', 'func_doc', 
'func_globals', 'func_name']
cod is a 'code' object

f: function at 10464816
==========================

g points to the same, unique, function as f. So that we can understand that g's 
__name__ actually is 'f'. But this shows that an object's "birthname" is 
somehwhat different from further name to which the object may be bound.
Now, h points to brand new object (as confirmed by its id); still, its __name__ 
is 'f'. This attr is well carried by the code and retrieved there, but it is 
not an attribute of code objects (cod.__name__ does not exist).
As I see it, the __name__ is somehow a third kind of name/id for objects. In 
fact, if 'id()' was called 'address()' instead, then __name__ could well be 
called __id__.
I also find highly meaningful that, among built_in types, the bool, int, float, 
str,... series do not have a __name__. (But this is probably an off-topic 
subject for the python_tutor list.)

 >>> Kent

Salutation,
denis



From wferguson1 at socal.rr.com  Mon Dec  1 21:20:03 2008
From: wferguson1 at socal.rr.com (WM.)
Date: Mon, 01 Dec 2008 12:20:03 -0800
Subject: [Tutor] Tutor Digest, Vol 58, Issue 2
In-Reply-To: <mailman.47.1228129213.3581.tutor@python.org>
References: <mailman.47.1228129213.3581.tutor@python.org>
Message-ID: <493446F3.8060002@socal.rr.com>

Stooges.py

i,j,k = 3,3,3
while i != 1:
     print 'Larry, Moe & Curly Joe!'
     i -= 1
     while j != 1:
         print 'Go Mad!!'
         j -= 1
while k != 1:
     print 'Go-go bad-bad!!'
     k -= 1
print '\nBye-bye.'

I am trying to learn loops.  These nested 'whiles' work OK but I would 
like to wrap this script in a 'for' loop. I have not been able to make 
that work.



From srilyk at gmail.com  Mon Dec  1 21:38:28 2008
From: srilyk at gmail.com (W W)
Date: Mon, 1 Dec 2008 14:38:28 -0600
Subject: [Tutor] Tutor Digest, Vol 58, Issue 2
In-Reply-To: <493446F3.8060002@socal.rr.com>
References: <mailman.47.1228129213.3581.tutor@python.org>
	<493446F3.8060002@socal.rr.com>
Message-ID: <333efb450812011238m79126e4y7e54768781129ce@mail.gmail.com>

Try this:

 for x in xrange(3, 0, -1):
   ....:     print x
   ....:
   ....:
3
2
1

HTH,
Wayne

On Mon, Dec 1, 2008 at 2:20 PM, WM. <wferguson1 at socal.rr.com> wrote:

> Stooges.py
>
> i,j,k = 3,3,3
> while i != 1:
>    print 'Larry, Moe & Curly Joe!'
>    i -= 1
>    while j != 1:
>        print 'Go Mad!!'
>        j -= 1
> while k != 1:
>    print 'Go-go bad-bad!!'
>    k -= 1
> print '\nBye-bye.'
>
> I am trying to learn loops.  These nested 'whiles' work OK but I would like
> to wrap this script in a 'for' loop. I have not been able to make that work.
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



-- 
To be considered stupid and to be told so is more painful than being called
gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness,
every vice, has found its defenders, its rhetoric, its ennoblement and
exaltation, but stupidity hasn't. - Primo Levi
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From eosher at gmail.com  Mon Dec  1 21:48:59 2008
From: eosher at gmail.com (Erica Osher)
Date: Mon, 1 Dec 2008 15:48:59 -0500
Subject: [Tutor] converting processing code to python code
Message-ID: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>

I have a simple processing code that I'm trying to work with in python, but
I keep getting syntax errors. Any help on changing the code would be greatly
appreciated. Thanks.

void setup() {
 size(550, 500);
 noStroke();
 smooth();
 fill(255, 255, 255, 150);
}


//Square 1 vars
int x1 = 5;
int y1 = 10;

int x1Speed = 2;
int y1Speed = 2;

//Square 2 Vars
int x2 = 150;
int y2 = 100;

int x2Speed = 4;
int y2Speed = 4;

int size = 100;

void draw() {
 background(180, 0, 0);
 drawSquare1();
 drawSquare2();

 checkCollision();
}



void drawSquare1() {
 if(x1<0 || x1>width-size) {
  x1Speed = -x1Speed;
 }

 if(y1<0 || y1>height-size) {
  y1Speed = -y1Speed;
 }

 x1+= x1Speed;
 y1+= y1Speed;
 rect(x1, y1, size, size);
}

void drawSquare2() {
 if(x2<0 || x2>width-size) {
  x2Speed = -x2Speed;
 }

 if(y2<0 || y2>height-size) {
  y2Speed = -y2Speed;
 }

 x2+= x2Speed;
 y2+= y2Speed;
 rect(x2, y2, size, size);
}

void checkCollision() {
 if(abs(x1-x2) < size && abs(y1-y2) < size) {
  println("Collision");
  //fill(255, 255, 255, 200);
  x1Speed=-x1Speed;
  x2Speed=-x2Speed;

  y1Speed=-y1Speed;
  y2Speed=-y2Speed;
 } else {
  fill(255, 255, 255, 100);
 };
}


-- 
Erica Osher
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From steve at alchemy.com  Mon Dec  1 21:59:23 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Mon, 1 Dec 2008 12:59:23 -0800
Subject: [Tutor] converting processing code to python code
In-Reply-To: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>
Message-ID: <20081201205923.GB61196@dragon.alchemy.com>

On Mon, Dec 01, 2008 at 03:48:59PM -0500, Erica Osher wrote:
> I have a simple processing code that I'm trying to work with in python, but
> I keep getting syntax errors. Any help on changing the code would be greatly
> appreciated. Thanks.

Could you show us what you have so far in Python and what syntax errors
you get?

Just as one example, this would be
pretty straightforward to convert straight
to Python, syntactically.  Whether you'd 
want to restructure the application to be
more optimally "Pythonic" is another topic
depending on what else is going on (or is 
this the entire program)?

> void drawSquare1() {
>  if(x1<0 || x1>width-size) {
>   x1Speed = -x1Speed;
>  }
> 
>  if(y1<0 || y1>height-size) {
>   y1Speed = -y1Speed;
>  }

def drawSquare1():
  if (x1 < 0 or x1 > width-size):
    x1 += x1Speed
    y1 += y1Speed
    rect(x1, y1, size, size)

Is that the sort of code you're coming up with?

One thing that strikes me off the top here is that
(in either language) you'd be better off not using
all those global variables.  Make your functions take
parameters and use them in your calculations.


-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From steve at alchemy.com  Mon Dec  1 22:02:02 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Mon, 1 Dec 2008 13:02:02 -0800
Subject: [Tutor] converting processing code to python code
In-Reply-To: <20081201205923.GB61196@dragon.alchemy.com>
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>
	<20081201205923.GB61196@dragon.alchemy.com>
Message-ID: <20081201210202.GC61196@dragon.alchemy.com>

On Mon, Dec 01, 2008 at 12:59:23PM -0800, Steve Willoughby wrote:
> > void drawSquare1() {
> >  if(x1<0 || x1>width-size) {
> >   x1Speed = -x1Speed;
> >  }
> > 
> >  if(y1<0 || y1>height-size) {
> >   y1Speed = -y1Speed;
> >  }
> 
> def drawSquare1():
>   if (x1 < 0 or x1 > width-size):
>     x1 += x1Speed
>     y1 += y1Speed
>     rect(x1, y1, size, size)

I think my eyes skipped somewhere while copying that
over.  The exact translation of that code snippet would
of course have been:

def drawSquare1():
  if x1 < 0 or x1 > width-size:
    x1Speed = -x1Speed
  if y1 < 0 or y1 > height-size:
    y1Speed = -y1Speed

Sorry 'bout that.

-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From alan.gauld at btinternet.com  Tue Dec  2 00:24:38 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 1 Dec 2008 23:24:38 -0000
Subject: [Tutor] Tutor Digest, Vol 58, Issue 2
References: <mailman.47.1228129213.3581.tutor@python.org><493446F3.8060002@socal.rr.com>
	<333efb450812011238m79126e4y7e54768781129ce@mail.gmail.com>
Message-ID: <gh1rnm$aib$1@ger.gmane.org>


"W W" <srilyk at gmail.com> wrote

> for x in xrange(3, 0, -1):
>   ....:     print x
>   ....:
>   ....:
> 3
> 2
> 1

Since the OP isn't using the loop counter a simpler solution
is simply

for x in range(3):

>> i,j,k = 3,3,3
>> while i != 1:
>>    print 'Larry, Moe & Curly Joe!'
>>    i -= 1
>>    while j != 1:
>>        print 'Go Mad!!'
>>        j -= 1
>> while k != 1:
>>    print 'Go-go bad-bad!!'
>>    k -= 1
>> print '\nBye-bye.'
>>
>> I am trying to learn loops.  These nested 'whiles' work OK but I 
>> would like
>> to wrap this script in a 'for' loop. I have not been able to make 
>> that work.

To the OP:
It helps if you show us what you tried so that we can see where
the misunderstanding is. What did you do and what happened?


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Tue Dec  2 00:30:20 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 1 Dec 2008 23:30:20 -0000
Subject: [Tutor] converting processing code to python code
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>
Message-ID: <gh1s2b$bhf$1@ger.gmane.org>


"Erica Osher" <eosher at gmail.com> wrote

>I have a simple processing code that I'm trying to work with in 
>python, but
> I keep getting syntax errors. Any help on changing the code would be 
> greatly
> appreciated. Thanks.

It would help to have some background.
What language are you translating from? It could be C/C++/JavaScript 
or Java.
Or possibly other C type languages. It might be significant!

Also show us what you tried and the syntax error messages.
That way we can figure out what it is you are doing wrong.

Otherwise we wind up writing your code for you and you learn nothing.
Then we have to do it all o er again next time you get stuck.
That's inefficient for both you and us!


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From eosher at gmail.com  Tue Dec  2 00:40:03 2008
From: eosher at gmail.com (Erica Osher)
Date: Mon, 1 Dec 2008 18:40:03 -0500
Subject: [Tutor] converting processing code to python code
In-Reply-To: <gh1s2b$bhf$1@ger.gmane.org>
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>
	<gh1s2b$bhf$1@ger.gmane.org>
Message-ID: <60b0585d0812011540h772d0730yf1202ee0cd10b616@mail.gmail.com>

The code was originally created for a Processing Project and I'm just
starting to learn python and I'd like to build on this code.

The syntax error I get is

*Traceback (most recent call last):
  File "nodebox/gui/mac/__init__.pyo", line 332, in _compileScript
  File "<untitled>", line 8
     int x1 = 5;
          ^
 SyntaxError: invalid syntax
*
any suggestions?

Thanks.

On Mon, Dec 1, 2008 at 6:30 PM, Alan Gauld <alan.gauld at btinternet.com>wrote:

>
> "Erica Osher" <eosher at gmail.com> wrote
>
>  I have a simple processing code that I'm trying to work with in python,
>> but
>> I keep getting syntax errors. Any help on changing the code would be
>> greatly
>> appreciated. Thanks.
>>
>
> It would help to have some background.
> What language are you translating from? It could be C/C++/JavaScript or
> Java.
> Or possibly other C type languages. It might be significant!
>
> Also show us what you tried and the syntax error messages.
> That way we can figure out what it is you are doing wrong.
>
> Otherwise we wind up writing your code for you and you learn nothing.
> Then we have to do it all o er again next time you get stuck.
> That's inefficient for both you and us!
>
>
> --
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



-- 
Erica Osher
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From steve at alchemy.com  Tue Dec  2 00:45:25 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Mon, 1 Dec 2008 15:45:25 -0800
Subject: [Tutor] converting processing code to python code
In-Reply-To: <60b0585d0812011540h772d0730yf1202ee0cd10b616@mail.gmail.com>
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>
	<gh1s2b$bhf$1@ger.gmane.org>
	<60b0585d0812011540h772d0730yf1202ee0cd10b616@mail.gmail.com>
Message-ID: <20081201234525.GD61196@dragon.alchemy.com>

On Mon, Dec 01, 2008 at 06:40:03PM -0500, Erica Osher wrote:
> The code was originally created for a Processing Project and I'm just
> starting to learn python and I'd like to build on this code.
> 
> The syntax error I get is
> 
> *Traceback (most recent call last):
>   File "nodebox/gui/mac/__init__.pyo", line 332, in _compileScript
>   File "<untitled>", line 8
>      int x1 = 5;

That's not even close to Python syntax.  That looks 
like a C-derived language.  I'd recommend going through
a basic Python tutorial first, so you can see how Python
works in a general sense before trying to convert code.

In Python, you don't need to declare variables like
that, you just assign them values.  So that line would
be simply:

  x1 = 5


>  SyntaxError: invalid syntax
> *
> any suggestions?
> 
> Thanks.
> 
> On Mon, Dec 1, 2008 at 6:30 PM, Alan Gauld <alan.gauld at btinternet.com>wrote:
> 
> >
> > "Erica Osher" <eosher at gmail.com> wrote
> >
> >  I have a simple processing code that I'm trying to work with in python,
> >> but
> >> I keep getting syntax errors. Any help on changing the code would be
> >> greatly
> >> appreciated. Thanks.
> >>
> >
> > It would help to have some background.
> > What language are you translating from? It could be C/C++/JavaScript or
> > Java.
> > Or possibly other C type languages. It might be significant!
> >
> > Also show us what you tried and the syntax error messages.
> > That way we can figure out what it is you are doing wrong.
> >
> > Otherwise we wind up writing your code for you and you learn nothing.
> > Then we have to do it all o er again next time you get stuck.
> > That's inefficient for both you and us!
> >
> >
> > --
> > Alan Gauld
> > Author of the Learn to Program web site
> > http://www.freenetpages.co.uk/hp/alan.gauld
> >
> > _______________________________________________
> > Tutor maillist  -  Tutor at python.org
> > http://mail.python.org/mailman/listinfo/tutor
> >
> 
> 
> 
> -- 
> Erica Osher

> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor


-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From srilyk at gmail.com  Tue Dec  2 01:23:31 2008
From: srilyk at gmail.com (W W)
Date: Mon, 1 Dec 2008 18:23:31 -0600
Subject: [Tutor] Tutor Digest, Vol 58, Issue 2
In-Reply-To: <gh1rnm$aib$1@ger.gmane.org>
References: <mailman.47.1228129213.3581.tutor@python.org>
	<493446F3.8060002@socal.rr.com>
	<333efb450812011238m79126e4y7e54768781129ce@mail.gmail.com>
	<gh1rnm$aib$1@ger.gmane.org>
Message-ID: <333efb450812011623q61817bd9m3f7106f7f8081ce5@mail.gmail.com>

On Mon, Dec 1, 2008 at 5:24 PM, Alan Gauld <alan.gauld at btinternet.com>wrote:

> <snip>Since the OP isn't using the loop counter a simpler solution
> is simply
>
> for x in range(3):


but the OP was looping from 3 to 1, and that's the easiest way I knew of.

-Wayne
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From wferguson1 at socal.rr.com  Tue Dec  2 01:44:02 2008
From: wferguson1 at socal.rr.com (WM.)
Date: Mon, 01 Dec 2008 16:44:02 -0800
Subject: [Tutor] 'for' loops
Message-ID: <493484D2.50603@socal.rr.com>

I recently asked a question about 'for' loops, expecting them to be 
similar to 'for-next' loops. I have looked at several on-line tutors but 
  am still in the dark about what 'for' loops do.
Does anyone have a plain English about the use of 'for' loops?
Are 'while' loops the only way Python runs a sub-routine over & over?

From steve at alchemy.com  Tue Dec  2 01:52:05 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Mon, 1 Dec 2008 16:52:05 -0800
Subject: [Tutor] 'for' loops
In-Reply-To: <493484D2.50603@socal.rr.com>
References: <493484D2.50603@socal.rr.com>
Message-ID: <20081202005205.GE61196@dragon.alchemy.com>

On Mon, Dec 01, 2008 at 04:44:02PM -0800, WM. wrote:
> I recently asked a question about 'for' loops, expecting them to be 
> similar to 'for-next' loops. I have looked at several on-line tutors but 
>  am still in the dark about what 'for' loops do.
> Does anyone have a plain English about the use of 'for' loops?
> Are 'while' loops the only way Python runs a sub-routine over & over?

No, both 'while' and 'for' loops are for running a block of code
(whether subroutine calls or whatever) over and over.  The difference
between the two is that 'while' will continue repeating the block
for however many iterations it takes until the condition is satisfied
('while x is true, for some expression x'), a 'for' loop will run the
block of code a set number of times ('once for each element of some
set of values').

So if you want to execute 'print' for every line of a file, you
would do this:

  for line in file:
    print line

If you wanted to double a value until it exceeded 100, you would
use a while loop:

  while x <= 100:
    x *= 2

If you just want something executed a specific number of times,
(like print "hello" 10 times), you can use a for loop:

  for i in range(10):
    print "hello"

This is, just like any 'for' loop, executing the block once per
element of a list.  The list in this case is range(10) which is
an expression that generates the list (0, 1, 2, ..., 9), so you
get one run through the code for each of those.

Does that help?

> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor

-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From srilyk at gmail.com  Tue Dec  2 01:53:28 2008
From: srilyk at gmail.com (W W)
Date: Mon, 1 Dec 2008 18:53:28 -0600
Subject: [Tutor] 'for' loops
In-Reply-To: <493484D2.50603@socal.rr.com>
References: <493484D2.50603@socal.rr.com>
Message-ID: <333efb450812011653v75b9d4f6ode34ea90d6ea71e7@mail.gmail.com>

On Mon, Dec 1, 2008 at 6:44 PM, WM. <wferguson1 at socal.rr.com> wrote:

> I recently asked a question about 'for' loops, expecting them to be similar
> to 'for-next' loops. I have looked at several on-line tutors but  am still
> in the dark about what 'for' loops do.
> Does anyone have a plain English about the use of 'for' loops?
> Are 'while' loops the only way Python runs a sub-routine over & over?


For loops are mainly used when you want a specific number of iterations,
such as looping over the elements of a list. In C/C++ you would do something
like this:

int myarray[] = {1, 2, 3, 4, 5};
for(int x = 0; x < 5; x++)
    printf("%d", myarray[x])

In python it would be much cleaner:

myarray = [1, 2, 3, 4, 5]
for x in myarray:
    print x

HTH,
Wayne

-- 
To be considered stupid and to be told so is more painful than being called
gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness,
every vice, has found its defenders, its rhetoric, its ennoblement and
exaltation, but stupidity hasn't. - Primo Levi
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From john at fouhy.net  Tue Dec  2 01:56:17 2008
From: john at fouhy.net (John Fouhy)
Date: Tue, 2 Dec 2008 13:56:17 +1300
Subject: [Tutor] 'for' loops
In-Reply-To: <493484D2.50603@socal.rr.com>
References: <493484D2.50603@socal.rr.com>
Message-ID: <5e58f2e40812011656o418d08efo24295b62fc0c2a04@mail.gmail.com>

On 02/12/2008, WM. <wferguson1 at socal.rr.com> wrote:
> I recently asked a question about 'for' loops, expecting them to be similar
> to 'for-next' loops. I have looked at several on-line tutors but  am still
> in the dark about what 'for' loops do.
>  Does anyone have a plain English about the use of 'for' loops?
>  Are 'while' loops the only way Python runs a sub-routine over & over?

I'm not sure exactly what you understand by a "for-next loop".

A for loop, essentially, iterates over a list [1].  e.g.

for fruit in ['apple', 'pear', 'banana', 'tomato']:
    print fruit

The loop will set the variable 'fruit' to be 'apple', 'pear', etc. on
each pass through the loop.

If you just want to do something n times, the usual idiom is:

for i in range(n):
    # do something, possibly involving i

range(n) is a function that will produce the list [0, 1, 2, ..., n-1].

Tutorials should cover this, so I'm not sure if I'm telling you
anything new.  If there's something particular you're stuck on, ask
:-)

-- 
John.

[1] Technically, it iterates over an iterator, which you can think of
as an object that behaves like a list when you throw it at a for loop.

From alan.gauld at btinternet.com  Tue Dec  2 02:17:41 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 01:17:41 -0000
Subject: [Tutor] 'for' loops
References: <493484D2.50603@socal.rr.com>
Message-ID: <gh22bl$rno$1@ger.gmane.org>


"WM." <wferguson1 at socal.rr.com> wrote

>I recently asked a question about 'for' loops, expecting them to be 
>similar to 'for-next' loops. I have looked at several on-line tutors 
>but am still in the dark about what 'for' loops do.

Python for loops are like foreach loops in other languages.
A Python for loop executes a bit of code for each element
in a sequence (list, string, dictionary, set, file etc)
It will keep looping until it runs out of items in the
sequence.

Thus to print each letter in a string:

mystring = 'foobar'
for ch in mystring:
   print ch

Or to print each element of a list:

mlist = [1,'2,'a',45, True]
for item in mylist:
    print item

And if you want to loop for a fixed number of iterations simply 
construct
a list with that number of elements. The range() function does that 
for
us, thus:

for n in range(12):
    print 'hi'

will print 'hi' 12 times.

> Does anyone have a plain English about the use of 'for' loops?
> Are 'while' loops the only way Python runs a sub-routine over & 
> over?

while loops are used much less in Python than in other languages
because for loops are so powerful.
while lops are generally used in cases where you don't know how
many times you need to loop or you want to loop 'forever'.

while True:
    print 'Can't stop me now!'

will keep on looping until you close the program

c = 0
while c != -1:
    c = int(raw_input('Enter a number(-1 to stop) '))
    print c

will keep looping until the user enters -1

More info and a comparison with JabaScript and VBScript can be
found in my tutor in the looping topic.


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Tue Dec  2 02:23:59 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 01:23:59 -0000
Subject: [Tutor] converting processing code to python code
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com><gh1s2b$bhf$1@ger.gmane.org>
	<60b0585d0812011540h772d0730yf1202ee0cd10b616@mail.gmail.com>
Message-ID: <gh22nf$sig$1@ger.gmane.org>

"Erica Osher" <eosher at gmail.com> wrote

> The code was originally created for a Processing Project and I'm 
> just
> starting to learn python and I'd like to build on this code.

The fact that you still don't tell us what the original language is 
suggests
you are not a very experienced programmer in any language. Is that
assumption correct?

> The syntax error I get is
>
> *Traceback (most recent call last):
>  File "nodebox/gui/mac/__init__.pyo", line 332, in _compileScript
>  File "<untitled>", line 8
>     int x1 = 5;
>          ^
> SyntaxError: invalid syntax

In Python variables are just names that refer to objects. The objects
can be of any type so we don't need to declare them as int, float,
char etc. You just need

x1 = 5

No semi colons are needed either.

However since this is such a basic Python statement I do think
you should take an hour or two to go through some of the complete
beginners tutorials found here:

http://wiki.python.org/moin/BeginnersGuide/NonProgrammers

Try mine if you like but there is a variety of styles for you to 
choose from.

Once you are familiar with the basics try converting your code again
and ask specific questions here for help. That will be much more
efficient for all of us than simply randomly trying things then asking
for help.

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From eosher at gmail.com  Tue Dec  2 02:28:10 2008
From: eosher at gmail.com (Erica Osher)
Date: Mon, 1 Dec 2008 20:28:10 -0500
Subject: [Tutor] converting processing code to python code
In-Reply-To: <gh22nf$sig$1@ger.gmane.org>
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com>
	<gh1s2b$bhf$1@ger.gmane.org>
	<60b0585d0812011540h772d0730yf1202ee0cd10b616@mail.gmail.com>
	<gh22nf$sig$1@ger.gmane.org>
Message-ID: <60b0585d0812011728n11549396oc40c1477792cdba6@mail.gmail.com>

I wrote the original code in a program called Processing. (
http://processing.org/)

Thanks for your advice, I definitely need some tutorials.

On Mon, Dec 1, 2008 at 8:23 PM, Alan Gauld <alan.gauld at btinternet.com>wrote:

> "Erica Osher" <eosher at gmail.com> wrote
>
>  The code was originally created for a Processing Project and I'm just
>> starting to learn python and I'd like to build on this code.
>>
>
> The fact that you still don't tell us what the original language is
> suggests
> you are not a very experienced programmer in any language. Is that
> assumption correct?
>
>  The syntax error I get is
>>
>> *Traceback (most recent call last):
>>  File "nodebox/gui/mac/__init__.pyo", line 332, in _compileScript
>>  File "<untitled>", line 8
>>    int x1 = 5;
>>         ^
>> SyntaxError: invalid syntax
>>
>
> In Python variables are just names that refer to objects. The objects
> can be of any type so we don't need to declare them as int, float,
> char etc. You just need
>
> x1 = 5
>
> No semi colons are needed either.
>
> However since this is such a basic Python statement I do think
> you should take an hour or two to go through some of the complete
> beginners tutorials found here:
>
> http://wiki.python.org/moin/BeginnersGuide/NonProgrammers
>
> Try mine if you like but there is a variety of styles for you to choose
> from.
>
> Once you are familiar with the basics try converting your code again
> and ask specific questions here for help. That will be much more
> efficient for all of us than simply randomly trying things then asking
> for help.
>
> HTH,
>
>
> --
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



-- 
Erica Osher
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From alan.gauld at btinternet.com  Tue Dec  2 02:27:08 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 01:27:08 -0000
Subject: [Tutor] Tutor Digest, Vol 58, Issue 2
References: <mailman.47.1228129213.3581.tutor@python.org><493446F3.8060002@socal.rr.com><333efb450812011238m79126e4y7e54768781129ce@mail.gmail.com><gh1rnm$aib$1@ger.gmane.org>
	<333efb450812011623q61817bd9m3f7106f7f8081ce5@mail.gmail.com>
Message-ID: <gh22tc$t03$1@ger.gmane.org>


"W W" <srilyk at gmail.com> wrote

>> for x in range(3):
>
> but the OP was looping from 3 to 1, and that's the easiest way I 
> knew of.

Yes, but they weren't using the counter so it didn't matter which
way they looped. I suspect the decrement pattern was just the one
they were most familiar  with in some other language (like Java? or 
VB?)

Alan G 



From alan.gauld at btinternet.com  Tue Dec  2 02:41:34 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 01:41:34 -0000
Subject: [Tutor] converting processing code to python code
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com><gh1s2b$bhf$1@ger.gmane.org><60b0585d0812011540h772d0730yf1202ee0cd10b616@mail.gmail.com><gh22nf$sig$1@ger.gmane.org>
	<60b0585d0812011728n11549396oc40c1477792cdba6@mail.gmail.com>
Message-ID: <gh23od$v3g$1@ger.gmane.org>


"Erica Osher" <eosher at gmail.com> wrote 

>I wrote the original code in a program called Processing. (
> http://processing.org/)

Aha! The language is actually called Processing. Now that's 
a new one on me. Thanks for the link, it does help to have 
the context. :-)

Now the next question, are you experienced in Processing 
or are you a beginner there too? If you are experienced in 
another language the best tutiorial is the standard Python 
tutorial found on the Python website. If you are a beginner 
in Processing as well stick to the newbies tutors I mentioned 
last time.

Regards,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


From alan.gauld at btinternet.com  Tue Dec  2 02:49:36 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 01:49:36 -0000
Subject: [Tutor] converting processing code to python code
References: <60b0585d0812011248i78504df4j931f41d496190d76@mail.gmail.com><gh1s2b$bhf$1@ger.gmane.org><60b0585d0812011540h772d0730yf1202ee0cd10b616@mail.gmail.com><gh22nf$sig$1@ger.gmane.org>
	<60b0585d0812011728n11549396oc40c1477792cdba6@mail.gmail.com>
Message-ID: <gh247f$aa$1@ger.gmane.org>


"Erica Osher" <eosher at gmail.com> wrote

>I wrote the original code in a program called Processing. (
> http://processing.org/)

Having had a look at the web site it is obvious that the hardest bit
of porting the Processing code to Python is that Python does not
support all the visual drawing functions that Processing does. Most
of them can be replicated by writing equivalent functions in Python
but that is a lot of work - effectively building a python vesion of
Processing! (That would be an exellent project BTW but not
one for a beginner!)

I tried a Google search. The best I could find was:

http://i.document.m05.de/?p=483

which suggests using Jython whicjh allows you to call the Java
processing libraies/classes from within Python code. But to
understand it I think you still need to go through the tutorials 
first.

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From bryan.fodness at gmail.com  Tue Dec  2 02:44:20 2008
From: bryan.fodness at gmail.com (Bryan Fodness)
Date: Mon, 1 Dec 2008 20:44:20 -0500
Subject: [Tutor] try except block for multiple statements
Message-ID: <fbf64d2b0812011744s503e2473g71b46f65d09dcd8a@mail.gmail.com>

I would like to use a try except to see if a value exists.  But, when I use
the following, if a does not exist it exits.  I understand why this does
this, but is there a way to get b,c, and d if a does not exist without using
a try except for every statement?

try:
    fo.write("a = %s\n" %plan.a)
    fo.write("b = %s\n" %plan.b)
    fo.write("c = %s\n" %plan.c)
    fo.write("d = %s\n" %plan.d)
except AttributeError:
    pass

-- 
"Any intelligent fool can make things bigger, more complex, and more
violent. It takes a touch of genius - and a lot of courage - to move in the
opposite direction. "  -Albert Einstein
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From john at fouhy.net  Tue Dec  2 02:54:26 2008
From: john at fouhy.net (John Fouhy)
Date: Tue, 2 Dec 2008 14:54:26 +1300
Subject: [Tutor] try except block for multiple statements
In-Reply-To: <fbf64d2b0812011744s503e2473g71b46f65d09dcd8a@mail.gmail.com>
References: <fbf64d2b0812011744s503e2473g71b46f65d09dcd8a@mail.gmail.com>
Message-ID: <5e58f2e40812011754g3389273bj3e1187b63a01da13@mail.gmail.com>

On 02/12/2008, Bryan Fodness <bryan.fodness at gmail.com> wrote:
> I would like to use a try except to see if a value exists.  But, when I use
> the following, if a does not exist it exits.  I understand why this does
> this, but is there a way to get b,c, and d if a does not exist without using
> a try except for every statement?
>
> try:
>     fo.write("a = %s\n" %plan.a)
>     fo.write("b = %s\n" %plan.b)
>     fo.write("c = %s\n" %plan.c)
>     fo.write("d = %s\n" %plan.d)
> except AttributeError:
>     pass

AFAIK, no -- but you could always use a loop.

attrs = ['a', 'b', 'c', 'd']
for attr in attrs:
  try:
    fo.write('A = %s\n' % getattr(plan, attr))
  except AttributeError:
    pass

-- 
John.

From bgailer at gmail.com  Tue Dec  2 03:31:57 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 01 Dec 2008 21:31:57 -0500
Subject: [Tutor] try except block for multiple statements
In-Reply-To: <fbf64d2b0812011744s503e2473g71b46f65d09dcd8a@mail.gmail.com>
References: <fbf64d2b0812011744s503e2473g71b46f65d09dcd8a@mail.gmail.com>
Message-ID: <49349E1D.5060508@gmail.com>

Bryan Fodness wrote:
> I would like to use a try except to see if a value exists.  But, when 
> I use the following, if a does not exist it exits.  I understand why 
> this does this, but is there a way to get b,c, and d if a does not 
> exist without using a try except for every statement?
>  
> try:
>     fo.write("a = %s\n" %plan.a)
>     fo.write("b = %s\n" %plan.b)
>     fo.write("c = %s\n" %plan.c)
>     fo.write("d = %s\n" %plan.d)
> except AttributeError:
>     pass
>
def foo(obj, attr):
  val = getattr(obj, attr, None)
  if val is not None:
    obj.write("%s = %s\n" % (attr, val))
foo(plan, "a")
foo(plan, "b")
foo(plan, "c")
foo(plan, "d")


> -- 
> "Any intelligent fool can make things bigger, more complex, and more 
> violent. It takes a touch of genius - and a lot of courage - to move 
> in the opposite direction. "  -Albert Einstein
> ------------------------------------------------------------------------
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From kent37 at tds.net  Tue Dec  2 04:00:36 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 1 Dec 2008 22:00:36 -0500
Subject: [Tutor] 'for' loops
In-Reply-To: <5e58f2e40812011656o418d08efo24295b62fc0c2a04@mail.gmail.com>
References: <493484D2.50603@socal.rr.com>
	<5e58f2e40812011656o418d08efo24295b62fc0c2a04@mail.gmail.com>
Message-ID: <1c2a2c590812011900t326e6241r630ac4a98c7e29a7@mail.gmail.com>

On Mon, Dec 1, 2008 at 7:56 PM, John Fouhy <john at fouhy.net> wrote:

> [1] Technically, it iterates over an iterator, which you can think of
> as an object that behaves like a list when you throw it at a for loop.

The object of the 'in' must be an iterable, which is an object that
can produce an iterator when asked. A list is an iterable, not an
iterator.

Kent

From kent37 at tds.net  Tue Dec  2 04:03:40 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 1 Dec 2008 22:03:40 -0500
Subject: [Tutor] attribute of built-in type
In-Reply-To: <4933DA0F.2030207@free.fr>
References: <49305ADF.7090706@free.fr>
	<1c2a2c590811281418x5f46b1ddrbe96e2be9bf7900b@mail.gmail.com>
	<49307855.9090900@free.fr>
	<1c2a2c590811290529n3a46150exc07a647e41f339dc@mail.gmail.com>
	<4931BD94.9000809@free.fr>
	<1c2a2c590811300520y3a69329fp1a042461c46d640b@mail.gmail.com>
	<4933DA0F.2030207@free.fr>
Message-ID: <1c2a2c590812011903j493e9ef2t8c7c6b88fd228886@mail.gmail.com>

Here is an idea that might help - you do have some control over
assignment to attributes of an object. If you stored your objects in
another object you could assign __name__ attributes automatically. For
example:

class Container(object):
	def __setattr__(self, name, value):
	   if not hasattr(value, '__name__'):
	      try:
	         value.__name__ = name
	      except:
	         pass
	   object.__setattr__(self, name, value)

class Item(object):
   pass

c = Container()
c.s = 'string'
c.i = Item()

print c.i.__name__   # i
print c.s.__name__   # AttributeError, can't add __name__ attribute to string

Kent

From wferguson1 at socal.rr.com  Tue Dec  2 04:57:12 2008
From: wferguson1 at socal.rr.com (WM.)
Date: Mon, 01 Dec 2008 19:57:12 -0800
Subject: [Tutor] I asked about loops
Message-ID: <4934B218.9070909@socal.rr.com>

and your response was most gratifying.  I think that I now have a handle 
  on the subject and want to say, "Thanks to you all."  WM

From cspears2002 at yahoo.com  Tue Dec  2 06:43:41 2008
From: cspears2002 at yahoo.com (Christopher Spears)
Date: Mon, 1 Dec 2008 21:43:41 -0800 (PST)
Subject: [Tutor] noise function
Message-ID: <924207.13128.qm@web51604.mail.re2.yahoo.com>

Hi!

Does anyone know if python has a noise function?



      

From aivars868 at gmail.com  Tue Dec  2 08:12:54 2008
From: aivars868 at gmail.com (aivars)
Date: Tue, 2 Dec 2008 09:12:54 +0200
Subject: [Tutor] sqlite3 Python25 parameter binding problem with UPDATE
	please help
Message-ID: <c5ad28970812012312j12b7695ao4dc51b6426345fa@mail.gmail.com>

Hello,

Does sqlite3 in python 2.5 supports parameter bindings in UPDATE
statement? When I do like the following:

oCon.execute("UPDATE rezerve SET latusaldo =? where gads =?;",(result, [year]))
oCon.commit()

it throws me the error:
sqlite3.InterfaceError: error binding parameter 1 probably unsupported type

All works OK when using INSERT with the same parameters.

On Google I found that python with MySQL supports this syntax (sorry I
am not able to find the link now) but I am not able to get it working
with sqlite3

Thanks in advance

Maybe I should as this question on sqlite list?

Aivars

From jmorcombe at westnet.com.au  Tue Dec  2 09:39:15 2008
From: jmorcombe at westnet.com.au (Jim Morcombe)
Date: Tue, 02 Dec 2008 17:39:15 +0900
Subject: [Tutor] cgi on novell/Appache
Message-ID: <4934F433.3020804@westnet.com.au>

I have a cgi script that I want to get running on an Apache server 
running under Novel.  I know absolutely nothing about novell.  I need to 
have the first line of the script point to the Python interpretter, but 
have no idea where it is.  (I don't have access to the server to play 
around on it.  I have to change the script, give it to the admin guy and 
let him load it.  He knows nothing about cgi, python, etc. )

What is the novel equivalent of "/usr/bin/python"?

Jim



From alan.gauld at btinternet.com  Tue Dec  2 09:51:10 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 08:51:10 -0000
Subject: [Tutor] noise function
References: <924207.13128.qm@web51604.mail.re2.yahoo.com>
Message-ID: <gh2stu$nrj$1@ger.gmane.org>


"Christopher Spears" <cspears2002 at yahoo.com> wrote 

> Does anyone know if python has a noise function?

What kind of noise function?
What would you expect it to produce?
A stream of random numbers perhaps?
A single number each time it is called?

And which noise profile should it follow?
Or would it be a multi dimensional noise model?

I don't know of any such function and I'm not sure wiothout 
more details how it would work in a general way even if it 
did exist. Can you give a speciofic example of what you expect?

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


From alan.gauld at btinternet.com  Tue Dec  2 09:55:17 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 08:55:17 -0000
Subject: [Tutor] sqlite3 Python25 parameter binding problem with
	UPDATEplease help
References: <c5ad28970812012312j12b7695ao4dc51b6426345fa@mail.gmail.com>
Message-ID: <gh2t5o$ohn$1@ger.gmane.org>


"aivars" <aivars868 at gmail.com> wrote

> oCon.execute("UPDATE rezerve SET latusaldo =? where gads 
> =?;",(result, [year]))
> oCon.commit()
>
> it throws me the error:
> sqlite3.InterfaceError: error binding parameter 1 probably 
> unsupported type

I assume its the [year] value it objects to.
I'm not sure what you expect SQLite to do with a list as a value, it 
does
not support a list type field.

> All works OK when using INSERT with the same parameters.

Are you sure? You can insert a list into a field?

> Maybe I should as this question on sqlite list?

Perhaps but I think it is the list parameter that it doesn't like.
Unless I misunderstand the syntax.

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Tue Dec  2 10:01:21 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 2 Dec 2008 09:01:21 -0000
Subject: [Tutor] cgi on novell/Appache
References: <4934F433.3020804@westnet.com.au>
Message-ID: <gh2tha$pkq$1@ger.gmane.org>

"Jim Morcombe" <jmorcombe at westnet.com.au> wrote

> running under Novel.  I know absolutely nothing about novell.  I 
> need to have the first line of the script point to the Python 
> interpretter,

I don't think that will do anything under Novell, assuming you mean
the Novell network OS and not Novell Linux? If its NovelWare then
you need to set the PATH to Python and set up the file associatiion
between your .py file and python. Then you need to use the cgi-bin
folder to store the file rather than your web app space.

At least that's what I did the last time I used a DOS based
server - but that was about 12 years ago!

If it's Novell Linux the standard /env/python should work.

> around on it.  I have to change the script, give it to the admin guy 
> and let him load it.  He knows nothing about cgi, python, etc. )

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From roadierich at googlemail.com  Tue Dec  2 13:32:44 2008
From: roadierich at googlemail.com (Richard Lovely)
Date: Tue, 2 Dec 2008 12:32:44 +0000
Subject: [Tutor] noise function
In-Reply-To: <gh2stu$nrj$1@ger.gmane.org>
References: <924207.13128.qm@web51604.mail.re2.yahoo.com>
	<gh2stu$nrj$1@ger.gmane.org>
Message-ID: <f0b4202b0812020432v7b029f08x2ee9d4d79ddd80e1@mail.gmail.com>

There's probably something like what you want within the "random" module.

at the interactive prompt, try:

import random
help(random)

---
Richard "Roadie Rich" Lovely, part of the JNP|UK Famile
www.theJNP.com



2008/12/2 Alan Gauld <alan.gauld at btinternet.com>:
>
> "Christopher Spears" <cspears2002 at yahoo.com> wrote
>>
>> Does anyone know if python has a noise function?
>
> What kind of noise function?
> What would you expect it to produce?
> A stream of random numbers perhaps?
> A single number each time it is called?
>
> And which noise profile should it follow?
> Or would it be a multi dimensional noise model?
>
> I don't know of any such function and I'm not sure wiothout more details how
> it would work in a general way even if it did exist. Can you give a
> speciofic example of what you expect?
>
> --
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

From jeff at dcsoftware.com  Tue Dec  2 17:40:04 2008
From: jeff at dcsoftware.com (Jeff Johnson)
Date: Tue, 02 Dec 2008 09:40:04 -0700
Subject: [Tutor] [Fwd: Python Course]
Message-ID: <493564E4.1080408@dcsoftware.com>

This was forwarded to me from one of our user group members:

"Hi everyone!

I just signed up for an online course in "Web Development with Python"
through DePaul University, which I think you might find interesting:
http://ipd.cdm.depaul.edu/wdp/Prog_WDP.htm

I talked to the folks in the admissions department and they said they
needed 10 students enrolled in order to go through with the course.
So I told them I would mention this to the python programmers I knew
to try to drum up enough applicants.

Best regards,

John T."

If anyone has any objection to posting this type of information, please 
let me know.  I thought members might be interested in available Python 
courses.

-- 
Jeff

Jeff Johnson
jeff at dcsoftware.com
Phoenix Python User Group - sunpiggies at googlegroups.com

From aivars868 at gmail.com  Tue Dec  2 19:33:20 2008
From: aivars868 at gmail.com (aivars)
Date: Tue, 2 Dec 2008 20:33:20 +0200
Subject: [Tutor] sqlite3 Python25 parameter binding problem with
	UPDATEplease help
In-Reply-To: <c5ad28970812020303l21d4b05al4401f0b258bc0e40@mail.gmail.com>
References: <c5ad28970812012312j12b7695ao4dc51b6426345fa@mail.gmail.com>
	<gh2t5o$ohn$1@ger.gmane.org>
	<c5ad28970812020303l21d4b05al4401f0b258bc0e40@mail.gmail.com>
Message-ID: <c5ad28970812021033l21af9ad9u44a8d4e1913dd566@mail.gmail.com>

Interestingly, when simply testing like this:

import sqlite3, sys
sPATH=r'e:\pythonexamples\aivars2.db'
oCon=sqlite3.connect(sPATH)

cur=oCon.cursor()

oCon.execute("""UPDATE rezerve SET latusaldo = ? WHERE gads = ?
""",(6000.0,'2006'))

oCon.commit()


it works. Therefore I am stuck since it looks like there is something
wrong in below function.

Thanks,

Aivars


2008/12/2 aivars <aivars868 at gmail.com>:
> Alan,
> Thanks.
>
> Ok I should have been more precise and give more code
> There is what I do:
>
> def starpiba(year, month, day):
>    datumsno=str(year+'-01-01') #beginning of year date
>    datumsuz=str(year+'-'+month+'-'+day) #period end date
>
>    result = (atlikumiBeiguKurss(year, month, day)-
> atlikumiDienasKurss(year, month, day))
>    ##print result
>    oCon=sqlite3.connect(sPATH)
>    if result<=0:
>        print abs(result)
>        oCon.execute("UPDATE rezerve SET latusaldo =? where gads
> =?;",(result, [year]))
>        oCon.commit()
>    else:
>        ##print 'aivars'
>        oCon.execute("UPDATE rezerve SET latusaldo =? where gads
> =?;",(result, [year]))
>
> Please bear in mind I am a noob in Python and I write spaggeti code.
>
> There is a table in my sqlite database called rezerve which shows the
> breakdown of a consolidated reserves item in a consolidated balance
> sheet report (if that says anything to you) by years. For the previous
> years the numbers does not change since they are already reported but
> for the current year it may change month by month until reported.
> Therefore, I wanted to update the numbers for the current year.
>
> The above python function works OK.
>
> Thanks
>
> Aivars
>
>
> 2008/12/2 Alan Gauld <alan.gauld at btinternet.com>:
>>
>> "aivars" <aivars868 at gmail.com> wrote
>>
>>> oCon.execute("UPDATE rezerve SET latusaldo =? where gads =?;",(result,
>>> [year]))
>>> oCon.commit()
>>>
>>> it throws me the error:
>>> sqlite3.InterfaceError: error binding parameter 1 probably unsupported
>>> type
>>
>> I assume its the [year] value it objects to.
>> I'm not sure what you expect SQLite to do with a list as a value, it does
>> not support a list type field.
>>
>>> All works OK when using INSERT with the same parameters.
>>
>> Are you sure? You can insert a list into a field?
>>
>>> Maybe I should as this question on sqlite list?
>>
>> Perhaps but I think it is the list parameter that it doesn't like.
>> Unless I misunderstand the syntax.
>>
>> --
>> Alan Gauld
>> Author of the Learn to Program web site
>> http://www.freenetpages.co.uk/hp/alan.gauld
>>
>> _______________________________________________
>> Tutor maillist  -  Tutor at python.org
>> http://mail.python.org/mailman/listinfo/tutor
>>
>

From aivars868 at gmail.com  Tue Dec  2 20:23:02 2008
From: aivars868 at gmail.com (aivars)
Date: Tue, 2 Dec 2008 21:23:02 +0200
Subject: [Tutor] sqlite3 Python25 parameter binding problem with
	UPDATEplease help
In-Reply-To: <c5ad28970812021033l21af9ad9u44a8d4e1913dd566@mail.gmail.com>
References: <c5ad28970812012312j12b7695ao4dc51b6426345fa@mail.gmail.com>
	<gh2t5o$ohn$1@ger.gmane.org>
	<c5ad28970812020303l21d4b05al4401f0b258bc0e40@mail.gmail.com>
	<c5ad28970812021033l21af9ad9u44a8d4e1913dd566@mail.gmail.com>
Message-ID: <c5ad28970812021123r22ccd6b6j99c7a16b91ee3e96@mail.gmail.com>

Hello again,

Finally I managed to get it working!

I had to remove [year] braces from the second argument - year. The
reason I used [] was the posts we exchanged recently (7th of November)
about CGI script where it was recommended by Kent that I put [] around
string argument:

Quote
The second argument to execute() is a *sequence* of parameter values.
A string is a sequence of characters, so by passing a plain string you
are saying that each character of the string is a parameter to the
SQL.

Try adding braces around the parameter to make  list:
cur.execute("insert into test (name) values (?)", [sPath])

Kent
Unquote

Now the year argument is string so I thought I should do the same
again but it is not working.
The reason is of course is that I am new to python and there are so
many things to learn so the question really is why in this case there
were no [] or () necessary?

Thanks in advance

Aivars



2008/12/2 aivars <aivars868 at gmail.com>:
> Interestingly, when simply testing like this:
>
> import sqlite3, sys
> sPATH=r'e:\pythonexamples\aivars2.db'
> oCon=sqlite3.connect(sPATH)
>
> cur=oCon.cursor()
>
> oCon.execute("""UPDATE rezerve SET latusaldo = ? WHERE gads = ?
> """,(6000.0,'2006'))
>
> oCon.commit()
>
>
> it works. Therefore I am stuck since it looks like there is something
> wrong in below function.
>
> Thanks,
>
> Aivars
>
>
> 2008/12/2 aivars <aivars868 at gmail.com>:
>> Alan,
>> Thanks.
>>
>> Ok I should have been more precise and give more code
>> There is what I do:
>>
>> def starpiba(year, month, day):
>>    datumsno=str(year+'-01-01') #beginning of year date
>>    datumsuz=str(year+'-'+month+'-'+day) #period end date
>>
>>    result = (atlikumiBeiguKurss(year, month, day)-
>> atlikumiDienasKurss(year, month, day))
>>    ##print result
>>    oCon=sqlite3.connect(sPATH)
>>    if result<=0:
>>        print abs(result)
>>        oCon.execute("UPDATE rezerve SET latusaldo =? where gads
>> =?;",(result, [year]))
>>        oCon.commit()
>>    else:
>>        ##print 'aivars'
>>        oCon.execute("UPDATE rezerve SET latusaldo =? where gads
>> =?;",(result, [year]))
>>
>> Please bear in mind I am a noob in Python and I write spaggeti code.
>>
>> There is a table in my sqlite database called rezerve which shows the
>> breakdown of a consolidated reserves item in a consolidated balance
>> sheet report (if that says anything to you) by years. For the previous
>> years the numbers does not change since they are already reported but
>> for the current year it may change month by month until reported.
>> Therefore, I wanted to update the numbers for the current year.
>>
>> The above python function works OK.
>>
>> Thanks
>>
>> Aivars
>>
>>
>> 2008/12/2 Alan Gauld <alan.gauld at btinternet.com>:
>>>
>>> "aivars" <aivars868 at gmail.com> wrote
>>>
>>>> oCon.execute("UPDATE rezerve SET latusaldo =? where gads =?;",(result,
>>>> [year]))
>>>> oCon.commit()
>>>>
>>>> it throws me the error:
>>>> sqlite3.InterfaceError: error binding parameter 1 probably unsupported
>>>> type
>>>
>>> I assume its the [year] value it objects to.
>>> I'm not sure what you expect SQLite to do with a list as a value, it does
>>> not support a list type field.
>>>
>>>> All works OK when using INSERT with the same parameters.
>>>
>>> Are you sure? You can insert a list into a field?
>>>
>>>> Maybe I should as this question on sqlite list?
>>>
>>> Perhaps but I think it is the list parameter that it doesn't like.
>>> Unless I misunderstand the syntax.
>>>
>>> --
>>> Alan Gauld
>>> Author of the Learn to Program web site
>>> http://www.freenetpages.co.uk/hp/alan.gauld
>>>
>>> _______________________________________________
>>> Tutor maillist  -  Tutor at python.org
>>> http://mail.python.org/mailman/listinfo/tutor
>>>
>>
>

From constantfables at gmail.com  Tue Dec  2 20:56:33 2008
From: constantfables at gmail.com (Daniel J Kramer)
Date: Tue, 2 Dec 2008 14:56:33 -0500
Subject: [Tutor] importing images and sound
Message-ID: <a44ceb880812021156n79fad44bj62cf1e000c33abde@mail.gmail.com>

Hi

I am writing a program based around a pub quiz.  I have been able to write
the program so it runs through a series of questions and gives users a score
at the end.

I need to import a specific font, images and sound.  Does anyone know a good
place to look for tutorials for this?  At the moment, I do not know where to
begin

thank you

-- 
Daniel J Kramer
Constant Fables
249 12th st #3
Brooklyn, NY 11215
(h) 347 223 4571
(m) 646 427 7430
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From steve at alchemy.com  Tue Dec  2 21:02:07 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Tue, 2 Dec 2008 12:02:07 -0800
Subject: [Tutor] importing images and sound
In-Reply-To: <a44ceb880812021156n79fad44bj62cf1e000c33abde@mail.gmail.com>
References: <a44ceb880812021156n79fad44bj62cf1e000c33abde@mail.gmail.com>
Message-ID: <20081202200207.GA16958@dragon.alchemy.com>

On Tue, Dec 02, 2008 at 02:56:33PM -0500, Daniel J Kramer wrote:
> Hi
> 
> I am writing a program based around a pub quiz.  I have been able to write
> the program so it runs through a series of questions and gives users a score
> at the end.
> 
> I need to import a specific font, images and sound.  Does anyone know a good
> place to look for tutorials for this?  At the moment, I do not know where to
> begin

That depends on what GUI toolkit you're using.  If you're
going to be doing a lot with sound and images, particularly
video clips, you might want to look at pymedia or pygame.


-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From srilyk at gmail.com  Tue Dec  2 21:49:20 2008
From: srilyk at gmail.com (W W)
Date: Tue, 2 Dec 2008 14:49:20 -0600
Subject: [Tutor] importing images and sound
In-Reply-To: <20081202200207.GA16958@dragon.alchemy.com>
References: <a44ceb880812021156n79fad44bj62cf1e000c33abde@mail.gmail.com>
	<20081202200207.GA16958@dragon.alchemy.com>
Message-ID: <333efb450812021249u6c35c8c2g385efef39450552@mail.gmail.com>

On Tue, Dec 2, 2008 at 2:02 PM, Steve Willoughby <steve at alchemy.com> wrote:

> <snip>
> That depends on what GUI toolkit you're using.  If you're
> going to be doing a lot with sound and images, particularly
> video clips, you might want to look at pymedia or pygame


Pyglet is another option.

-Wayne
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From jeremiah.jester at panasonic.aero  Tue Dec  2 22:08:09 2008
From: jeremiah.jester at panasonic.aero (Jeremiah Jester)
Date: Tue, 02 Dec 2008 13:08:09 -0800
Subject: [Tutor] dictionary looping problem
Message-ID: <1228252089.16380.11.camel@M13425>

Hello,

I'm trying to gather a list of files and md5 hash them to do a checksum.
I've created a function for each dictionary. However, when i print out
the dictionary I don't get all the items. Any ideas?

Thanks<
JJ

CODE:

#!/usr/bin/python
import os
import md5
import sys

source={}
target={}

source_path="/path/source"
target_path="/path/target"

def gather_files(dir,dict):
        os.chdir(dir)
        names=os.listdir(dir)
        for filename in names:
                hash=os.system("md5 "+ filename)
                dict[hash] = filename
        print dict

gather_files(source_path,source)
gather_files(target_path,target)


OUTPUT:

# python new.py 
b481bb58b296a62d744d3006d0156f61 1
e07910a06a086c83ba41827aa00b26ed 3
749a92a5ba327db2f2711b1a8d3cc0ab 2
{0: '2'}
b481bb58b296a62d744d3006d0156f61 1
e6139f93eb47c9fe7eb7fc5ddb586511 3
7ce1a3a4baf75dea4397e36c97e1fc0b 2
{0: '2'}



Disclaimer: The information contained in this transmission, including any 
attachments, may contain confidential information of Panasonic Avionics
Corporation.  This transmission is intended only for the use of the 
addressee(s) listed above.  Unauthorized review, dissemination or other use 
of the information contained in this transmission is strictly prohibited. 
If you have received this transmission in error or have reason to believe 
you are not authorized to receive it, please notify the sender by return 
email and promptly delete the transmission.



From steve at alchemy.com  Tue Dec  2 22:25:34 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Tue, 2 Dec 2008 13:25:34 -0800
Subject: [Tutor] dictionary looping problem
In-Reply-To: <1228252089.16380.11.camel@M13425>
References: <1228252089.16380.11.camel@M13425>
Message-ID: <20081202212534.GD16958@dragon.alchemy.com>

On Tue, Dec 02, 2008 at 01:08:09PM -0800, Jeremiah Jester wrote:
> Hello,
> 
> I'm trying to gather a list of files and md5 hash them to do a checksum.
> I've created a function for each dictionary. However, when i print out
> the dictionary I don't get all the items. Any ideas?

Yep.  Don't use os.system() there.  

1. you're running the "md5" program externally when you don't need to,
   since Python has the ability to compute md5 checksums on its own,
   which you already know because you imported that module at the top
   of your script (and then didn't use).

2. The return value from os.system() is NOT the hash, so what you're
   storing in the dictionary is not going to be that unique, and so
   each call which yields the same return value (0, usually) will 
   overwrite that element in the dict.

-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From jeremiah.jester at panasonic.aero  Tue Dec  2 23:26:40 2008
From: jeremiah.jester at panasonic.aero (Jeremiah Jester)
Date: Tue, 02 Dec 2008 14:26:40 -0800
Subject: [Tutor] dictionary looping problem
In-Reply-To: <20081202212534.GD16958@dragon.alchemy.com>
References: <1228252089.16380.11.camel@M13425>
	<20081202212534.GD16958@dragon.alchemy.com>
Message-ID: <1228256800.16380.17.camel@M13425>

Thanks for clearing this up for me. 

On Tue, 2008-12-02 at 13:25 -0800, Steve Willoughby wrote:
> On Tue, Dec 02, 2008 at 01:08:09PM -0800, Jeremiah Jester wrote:
> > Hello,
> >
> > I'm trying to gather a list of files and md5 hash them to do a
> checksum.
> > I've created a function for each dictionary. However, when i print
> out
> > the dictionary I don't get all the items. Any ideas?
> 
> Yep.  Don't use os.system() there. 
> 
> 1. you're running the "md5" program externally when you don't need to,
>    since Python has the ability to compute md5 checksums on its own,
>    which you already know because you imported that module at the top
>    of your script (and then didn't use).
> 
> 2. The return value from os.system() is NOT the hash, so what you're
>    storing in the dictionary is not going to be that unique, and so
>    each call which yields the same return value (0, usually) will
>    overwrite that element in the dict.
> 
> --
> Steve Willoughby    |  Using billion-dollar satellites
> steve at alchemy.com   |  to hunt for Tupperware.
> 
> 
> 



Disclaimer: The information contained in this transmission, including any 
attachments, may contain confidential information of Panasonic Avionics
Corporation.  This transmission is intended only for the use of the 
addressee(s) listed above.  Unauthorized review, dissemination or other use 
of the information contained in this transmission is strictly prohibited. 
If you have received this transmission in error or have reason to believe 
you are not authorized to receive it, please notify the sender by return 
email and promptly delete the transmission.



From alan.gauld at btinternet.com  Wed Dec  3 01:02:14 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 3 Dec 2008 00:02:14 -0000
Subject: [Tutor] sqlite3 Python25 parameter binding problem
	withUPDATEplease help
References: <c5ad28970812012312j12b7695ao4dc51b6426345fa@mail.gmail.com><gh2t5o$ohn$1@ger.gmane.org><c5ad28970812020303l21d4b05al4401f0b258bc0e40@mail.gmail.com><c5ad28970812021033l21af9ad9u44a8d4e1913dd566@mail.gmail.com>
	<c5ad28970812021123r22ccd6b6j99c7a16b91ee3e96@mail.gmail.com>
Message-ID: <gh4ia7$lcr$1@ger.gmane.org>

"aivars" <aivars868 at gmail.com> wrote

> Finally I managed to get it working!
>
> I had to remove [year] braces from the second argument - year.

You really need to do some reading on basicv Python before
you go any further, otherwise you will never understand what
you are doing.

That is what I told you was wrong in the first place - you can't
pass a list of values (even of one value)  into a database field.
But you obviously didn't realize that putting square brackets
(not braces which are {} and signify a dictionary) indicates
a list.

> reason I used [] was the posts we exchanged recently (7th of 
> November)
> about CGI script where it was recommended by Kent that I put [] 
> around
> string argument:

But that was an entirely different scenario, again you need to do some
basic level reading so that you understand what we are telling you.
Blindly using "poke and hope" techniques leads to an excercise
in frustration for you and us both.

> The second argument to execute() is a *sequence* of parameter 
> values.
> A string is a sequence of characters, so by passing a plain string 
> you
> are saying that each character of the string is a parameter to the
> SQL.
>
> Try adding braces around the parameter to make  list:
> cur.execute("insert into test (name) values (?)", [sPath])

Notice, Kent told you to "make a list" by putting[] around
your string. But in that case the arument was looking for a sequence
(eg list) of values. In your case you were trying to insert a list of 
values
into a single field which you can't do in normal SQL

> Now the year argument is string so I thought I should do the same
> again but it is not working.

Yes but it is a single string so you need to pass a single string.
In the previous case the SQL was looking for a list of arguments
but you passed a single string so the execute interpreted that
as a list of letters.

You must ensure that the arguments in the execute match
what the SQL is expecting. And that usually means both matching
what you defined the database to be and the nature of the operation.

> The reason is of course is that I am new to python and there are so
> many things to learn so the question really is why in this case 
> there
> were no [] or () necessary?

See above, but you really need to take the time out to understand
the basics of Python.

Try reading my  tutorial, in particular the "raw materials"  topic
which covers the different Python data types. Then try my database
topic near the end. But ideally just take a few hours - literally an
afternoon will do - to go through any beginners tutorial. They will
all cover these elementary issues.


>>>> Perhaps but I think it is the list parameter that it doesn't 
>>>> like.
>>>> Unless I misunderstand the syntax.
>>>>
>>>> --
>>>> Alan Gauld
>>>> Author of the Learn to Program web site
>>>> http://www.freenetpages.co.uk/hp/alan.gauld


Alan G. 



From alan.gauld at btinternet.com  Wed Dec  3 01:09:40 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 3 Dec 2008 00:09:40 -0000
Subject: [Tutor] dictionary looping problem
References: <1228252089.16380.11.camel@M13425>
Message-ID: <gh4io4$mir$1@ger.gmane.org>


"Jeremiah Jester" <jeremiah.jester at panasonic.aero> wrote


> I've created a function for each dictionary. However, when i print 
> out
> the dictionary I don't get all the items. Any ideas?

You should only get a very small number indeed!

>        for filename in names:
>                hash=os.system("md5 "+ filename)
>                dict[hash] = filename

os.system only returns the exit code of the command not
the output of the command. In most cases that will be 0 to
indicate no errors.

You need to use the subprocess module (or any of the older
alternatives such as popen) to fetch the actual output of the
command from stdout and assign it to hash.

But better still use one of the python modules to do the
hashing instead of calling the OS!

I think the hashlib module's md5 function does what you want.

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From juryef at yahoo.com  Wed Dec  3 02:08:21 2008
From: juryef at yahoo.com (Judith Flores)
Date: Tue, 2 Dec 2008 17:08:21 -0800 (PST)
Subject: [Tutor] Making a dictionary of dictionaries from csv file
Message-ID: <811719.59207.qm@web34707.mail.mud.yahoo.com>

Dear Python community,

   I have been trying to create a dictionary of dictionaries (and more dictionaries) from a csv file. The csv file contains longitudinal data corresponding to names. The following is just a very (very) simple example of how the data looks:

NameDayweighttemp
name114537
name135536
name215936
name233436.5
name316637
name338736.8


So far I have written this:

from csv import *

f=open('myfile.csv',"rt")

row={}
maindict={}

reader=DictReader(f)

for row in reader:
maindict[row['Name']=row


then I can access the weight of a given name like this:

wg=int(maindict[['name1']['weight'])



My question is the following:

How can I convert the csv to a dictionary that would have the following structure?

maindict = {

'name1' : { 
'Day' : {

1 : { 'weight' : '45', 'temp' : '37' } ,

3 : { 'weight' : '55', 'temp' : '36' }

  }

},

'name2' : { ..... # and we repeat the same structure for the rest of the names.



}

 
>From my code above you can of course guess that it doesn't make beyond the level of name.

Thank you very much,

Judith


      

From aivars868 at gmail.com  Wed Dec  3 06:43:39 2008
From: aivars868 at gmail.com (aivars)
Date: Wed, 3 Dec 2008 07:43:39 +0200
Subject: [Tutor] sqlite3 Python25 parameter binding problem
	withUPDATEplease help
In-Reply-To: <gh4ia7$lcr$1@ger.gmane.org>
References: <c5ad28970812012312j12b7695ao4dc51b6426345fa@mail.gmail.com>
	<gh2t5o$ohn$1@ger.gmane.org>
	<c5ad28970812020303l21d4b05al4401f0b258bc0e40@mail.gmail.com>
	<c5ad28970812021033l21af9ad9u44a8d4e1913dd566@mail.gmail.com>
	<c5ad28970812021123r22ccd6b6j99c7a16b91ee3e96@mail.gmail.com>
	<gh4ia7$lcr$1@ger.gmane.org>
Message-ID: <c5ad28970812022143y3686d9eg7b1cbcbe0ee79dc0@mail.gmail.com>

Thanks, Alan, for your advice.
I fully agree with you - I still need to understand basic Python (I
actually warned that I am a complete noob) and how it works. And
probably I need a couple of goof books.
I once told you that I consider your website an excellent one and I am
going there from time to time and will do it again.

Maybe I am trying to do the things which are too advanced for my level
of python knowledge - databases, web development, which I understand
are considered as advanced topics but the reason is that for me I need
a real project to work with to learn a programming language. That was
the case also with VBA (visual basic for applications) - learning for
the sake of learning almost never worked with me. It does not mean I
am an expert in VBA - far from it! But I had this project working with
MS Excel VBA+ MS SQL Server Express 2005 T-SQL - an automated
financial accounting consolidated reporting application. I am pumping
data from two remote Interbase/Firebird databases, putting it in a
local MS SQL Server DB, processing with T-SQL and doing the reporting
with Excel.

Now I am working to do the same with Python and SQLite at the same
time learning on my way them both. And if you work on a real thing
there are many bits and pieces which are coming up - and its not like
this 'spam' and 'egg' thing all the time.

Also I am completely self-taught in programming.

I see what was my problem in particular in this case and I understand
it now. And I will try not to bother people on this list too often. Or
If I do please feel free tell me to !@#$% off and do some more
reading!

Again, thank you Alan for the help!

Aivars



2008/12/3 Alan Gauld <alan.gauld at btinternet.com>:
> "aivars" <aivars868 at gmail.com> wrote
>
>> Finally I managed to get it working!
>>
>> I had to remove [year] braces from the second argument - year.
>
> You really need to do some reading on basicv Python before
> you go any further, otherwise you will never understand what
> you are doing.
>
> That is what I told you was wrong in the first place - you can't
> pass a list of values (even of one value)  into a database field.
> But you obviously didn't realize that putting square brackets
> (not braces which are {} and signify a dictionary) indicates
> a list.
>
>> reason I used [] was the posts we exchanged recently (7th of November)
>> about CGI script where it was recommended by Kent that I put [] around
>> string argument:
>
> But that was an entirely different scenario, again you need to do some
> basic level reading so that you understand what we are telling you.
> Blindly using "poke and hope" techniques leads to an excercise
> in frustration for you and us both.
>
>> The second argument to execute() is a *sequence* of parameter values.
>> A string is a sequence of characters, so by passing a plain string you
>> are saying that each character of the string is a parameter to the
>> SQL.
>>
>> Try adding braces around the parameter to make  list:
>> cur.execute("insert into test (name) values (?)", [sPath])
>
> Notice, Kent told you to "make a list" by putting[] around
> your string. But in that case the arument was looking for a sequence
> (eg list) of values. In your case you were trying to insert a list of values
> into a single field which you can't do in normal SQL
>
>> Now the year argument is string so I thought I should do the same
>> again but it is not working.
>
> Yes but it is a single string so you need to pass a single string.
> In the previous case the SQL was looking for a list of arguments
> but you passed a single string so the execute interpreted that
> as a list of letters.
>
> You must ensure that the arguments in the execute match
> what the SQL is expecting. And that usually means both matching
> what you defined the database to be and the nature of the operation.
>
>> The reason is of course is that I am new to python and there are so
>> many things to learn so the question really is why in this case there
>> were no [] or () necessary?
>
> See above, but you really need to take the time out to understand
> the basics of Python.
>
> Try reading my  tutorial, in particular the "raw materials"  topic
> which covers the different Python data types. Then try my database
> topic near the end. But ideally just take a few hours - literally an
> afternoon will do - to go through any beginners tutorial. They will
> all cover these elementary issues.
>
>
>>>>> Perhaps but I think it is the list parameter that it doesn't like.
>>>>> Unless I misunderstand the syntax.
>>>>>
>>>>> --
>>>>> Alan Gauld
>>>>> Author of the Learn to Program web site
>>>>> http://www.freenetpages.co.uk/hp/alan.gauld
>
>
> Alan G.
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

From alan.gauld at btinternet.com  Wed Dec  3 09:20:25 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 3 Dec 2008 08:20:25 -0000
Subject: [Tutor] sqlite3 Python25 parameter binding
	problemwithUPDATEplease help
References: <c5ad28970812012312j12b7695ao4dc51b6426345fa@mail.gmail.com><gh2t5o$ohn$1@ger.gmane.org><c5ad28970812020303l21d4b05al4401f0b258bc0e40@mail.gmail.com><c5ad28970812021033l21af9ad9u44a8d4e1913dd566@mail.gmail.com><c5ad28970812021123r22ccd6b6j99c7a16b91ee3e96@mail.gmail.com><gh4ia7$lcr$1@ger.gmane.org>
	<c5ad28970812022143y3686d9eg7b1cbcbe0ee79dc0@mail.gmail.com>
Message-ID: <gh5fg9$pgr$1@ger.gmane.org>

"aivars" <aivars868 at gmail.com> wrote

> I fully agree with you - I still need to understand basic Python (I
> actually warned that I am a complete noob) and how it works. And
> probably I need a couple of goof books.

To be honest you don;t need many books on Python, the web resources
are adequate. Pesonally I only use about 4 or 5 books asnd they are
almost all on specific topics: Tkinter, wxPythn,TurboGears, Networks 
etc.
Python in a Nutshell is the only general book I use as a reference.

> Maybe I am trying to do the things which are too advanced for my 
> level

Just on the edge given your knowledge level.

> are considered as advanced topics but the reason is that for me I 
> need
> a real project to work with to learn a programming language.

Thats a good thing. But be aware of the dangers - you will learn a
lot of bad habits that will cause you problems later. Its liker 
learning
to play a musical instrument by ear just by puicking out the notes
of your favourite tune. Unless you learn chords and proper finger
positions etc you will never get beyond being a beginner/intermediate
level.

Same with programming, you do need to knuckle down and learn
some of the basic theory and principles if you ever want to progress
beyond that stage.

> Also I am completely self-taught in programming.

Not in itself a problem provided you do take the time to actually 
learn
rather than just picking up bits n pieces ad hoc.

> it now. And I will try not to bother people on this list too often.

Its not the frequency of asking thats an issue, we don't ,mind
answering questions, thats what we are here for. But do take the
time to *understand* the answer, don't just think "OK I'll stick []
around values and that'll mayubermake it work" Take the time to
really understand why [] worked in the first case but actually
caused the problem in the second. And if you don't understand,
ask for the explanation.

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Wed Dec  3 09:34:00 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 3 Dec 2008 08:34:00 -0000
Subject: [Tutor] Making a dictionary of dictionaries from csv file
References: <811719.59207.qm@web34707.mail.mud.yahoo.com>
Message-ID: <gh5g9p$s1n$1@ger.gmane.org>


"Judith Flores" <juryef at yahoo.com> wrote

>   I have been trying to create a dictionary of dictionaries
> (and more dictionaries) from a csv file.

Your code below suffers from sloppiness in the number of []
which makes it hard to know exactly what the problem might be.
But in principle what you are doing is fine and should work
beyond 2 levels.

However I would suggest that it might be esier to use classes
instead of dictionaries. Dictionaries are fine for many things but
can become a bit tortuous to navigate and maintain.

> NameDayweighttemp
> name114537
> name135536
> name215936

I assume there should be some commas (or other separators)
in there? Othewise how do you expect the csv module to separate
the data?

> row={}
> maindict={}
> reader=DictReader(f)
>
> for row in reader:
> maindict[row['Name']=row

I assume you have a second closing ] after Name?

Also you are overwriting the row for each name. So you only
store the last entry. So you need to separate the data further.
Something like

maindict[row[name]] [row[day]] = (row.weight, row,temp)

Which would look like

{name1: {day1: (w,t), day2 : (w,t),
              day2: (w,t)},
name2: {day3: (w,t)....

Which looks a bit like what you want I think?

> then I can access the weight of a given name like this:
>
> wg=int(maindict[['name1']['weight'])

I assume thats a single open { before name1?

> My question is the following:
>
> How can I convert the csv to a dictionary that would have the 
> following structure?
>
> maindict = {
>
> 'name1' : {
> 'Day' : {
>
> 1 : { 'weight' : '45', 'temp' : '37' } ,
>
> 3 : { 'weight' : '55', 'temp' : '36' }
>
>  }
>
> },

See above

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld




From kent37 at tds.net  Wed Dec  3 12:43:01 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 3 Dec 2008 06:43:01 -0500
Subject: [Tutor] Making a dictionary of dictionaries from csv file
In-Reply-To: <gh5g9p$s1n$1@ger.gmane.org>
References: <811719.59207.qm@web34707.mail.mud.yahoo.com>
	<gh5g9p$s1n$1@ger.gmane.org>
Message-ID: <1c2a2c590812030343n7007f488v433c3608c61ce627@mail.gmail.com>

On Wed, Dec 3, 2008 at 3:34 AM, Alan Gauld <alan.gauld at btinternet.com> wrote:

> Also you are overwriting the row for each name. So you only
> store the last entry. So you need to separate the data further.
> Something like
>
> maindict[row[name]] [row[day]] = (row.weight, row,temp)

This will not quite work. It will give KeyErrors because the
second-level dicts don't exist in maindict. One way to fix this is to
use collections.defaultdict:
from collections import defaultdict
maindict = defaultdict(dict)

Now maindict uses an empty dictionary as its default value.

For another level of nesting (the 'Day' level you show in your
example) this becomes a bit more complex, see this discussion and the
link:
http://thread.gmane.org/gmane.comp.python.tutor/46006

Kent

From roadierich at googlemail.com  Wed Dec  3 14:57:42 2008
From: roadierich at googlemail.com (Rich Lovely)
Date: Wed, 3 Dec 2008 13:57:42 +0000
Subject: [Tutor] Making a dictionary of dictionaries from csv file
Message-ID: <992203C7-FE30-460B-B730-61C5AAB9DB03@googlemail.com>

How about this:

def recursiveDictFactory():
    return defaultdict(recursiveDictFactory)

dictOfDictsOfDictsEtc = defaultdict(recursiveDictFactory)

---
Richard "Roadie Rich" Lovely
Part of the JNP|UK Famille
www.theJNP.com

(Sent from my iPod - please allow me a few typos: it's a very small  
keyboard)

On 3 Dec 2008, at 11:43, "Kent Johnson" <kent37 at tds.net> wrote:

> On Wed, Dec 3, 2008 at 3:34 AM, Alan Gauld  
> <alan.gauld at btinternet.com> wrote:
>
>> Also you are overwriting the row for each name. So you only
>> store the last entry. So you need to separate the data further.
>> Something like
>>
>> maindict[row[name]] [row[day]] = (row.weight, row,temp)
>
> This will not quite work. It will give KeyErrors because the
> second-level dicts don't exist in maindict. One way to fix this is to
> use collections.defaultdict:
> from collections import defaultdict
> maindict = defaultdict(dict)
>
> Now maindict uses an empty dictionary as its default value.
>
> For another level of nesting (the 'Day' level you show in your
> example) this becomes a bit more complex, see this discussion and the
> link:
> http://thread.gmane.org/gmane.comp.python.tutor/46006
>
> Kent
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor


From timmichelsen at gmx-topmail.de  Wed Dec  3 22:46:44 2008
From: timmichelsen at gmx-topmail.de (Tim Michelsen)
Date: Wed, 03 Dec 2008 22:46:44 +0100
Subject: [Tutor] using windows wide proxy settings
Message-ID: <gh6uo4$b30$1@ger.gmane.org>

Hello,
is there any possibility in python to retrieve the system wide internet 
connection settings?

I would like to access the proxy settings stored in
Internet Explorer -> Extras -> Options -> Connection -> LAN settings.

This would later be used by urllib. My aim is not to bother the user 
with another place to set the proxy when being behind a corporate firewall.

Thanks in advance & regards,
Timmie


From denis.spir at free.fr  Wed Dec  3 22:35:03 2008
From: denis.spir at free.fr (spir)
Date: Wed, 03 Dec 2008 22:35:03 +0100
Subject: [Tutor] [Fwd: Re: Making a dictionary of dictionaries from csv file]
Message-ID: <4936FB87.9000104@free.fr>

Judith Flores a ?crit :
> Dear Python community,
>
>    I have been trying to create a dictionary of dictionaries (and more 
dictionaries) from a csv file. The csv file contains longitudinal data
corresponding to names. The following is just a very (very) simple example of
how the data looks:
>
> NameDayweighttemp
> name114537
> name135536
> name215936
> name233436.5
> name316637
> name338736.8

Apart from the lack of ',', I'm not really sure to understand the logical
structure of you data: for instance, can there be the same day for several
names? If not, then the problem is simpler as the day uniquely identifiesyour
data. Anyway, it seems clear that a (name+day) key is unique for a
(weight,temp) data pair. right?

> So far I have written this:
>
> from csv import *
>
> f=open('myfile.csv',"rt")
>
> row={}
> maindict={}
>
> reader=DictReader(f)
>
> for row in reader:
> maindict[row['Name']=row
>
>
> then I can access the weight of a given name like this:
>
> wg=int(maindict[['name1']['weight'])
>
>
>
> My question is the following:
>
> How can I convert the csv to a dictionary that would have the following structure?
>
> maindict = {
> 'name1' : {
> 'Day' : {
> 1 : { 'weight' : '45', 'temp' : '37' } ,
> 3 : { 'weight' : '55', 'temp' : '36' }
>   }
> },
> 'name2' : { ..... # and we repeat the same structure for the rest of the names.
> }
>>From my code above you can of course guess that it doesn't make beyondthe > 
> level of name.

If I understand well, you can clarify your problem for instance with such a 
data type (all pseudo code, untested):
class Measure(object):
	def __init__(self,weight,temp):
		self.weight = weight
		self.temp = temp
This will remove one dict level. You can create a data object
x = Measure(weight,temp)
which weight and temp attributes can be set, changed, & read individually using
'x.weight' and 'x.temp'. Much nicer, I think.

At higher level, you are then able to put such measure objects in a simple dict
with day keys and Measure values. So that an individual Measure object will
actually be accessed as a dict value, e.g.:
day_measures = {day:measure, day:measure...}
measure = day_measures[day]
temp = day_measures[day].temp (=measure.temp)

At top-level, you then need a construct to hold the set of name data objects.
As they are named, it could be a nesting dictionary of (name:day_measures)
pairs. This will be especially efficient if you frequently need accessing the
data through the 'name' key.

An alternative (which I would chose to avoid nested dicts) is to use the python
ability to create attributes which names are known at runtime only, using the
setattr() built-in function:

setattr(obj,name,val) will give the object 'obj' an attribute which full name
will be obj.name, and value will be val. Very nice (*).

That way, you can have an overall Data object (chose an appropriate name) with
a whole bunch of attributes called by their 'name' and which individual value 
is a day_measures dict:
data
	name1 : day_measures dict
	name2 : day_measures dict
	...

You need to create an attribute for each set of (named) day_measures dict you
read from the CSV file.

class Data(object): pass
data = Data()	# new empty object

while not end_of_file:
	<identify name>
	<read the set of (day:measure) pairs from CSV into dict>
	# create attribute to store the measures into data object
	setattr(data, name, dict)
# done

Now, from the outest scope, an individual data item is spelled e.g.:
data.name[day].temp
(which I find much more legible)

> Thank you very much,
>
> Judith

Hope I haven't totally miusunderstood your problem.
Salutation,
denis

(*) The ordinary way to create an attr beeing to write
obj.name = value
you need to know the name at coding time. The setattr() syntax instead allows
to set the name at runtime like a dict key. So that any ordinary object becomes
an alternative to dicts.
[A major redondance, indeed -- I personly do not really know anymore what  the 
proper use of a dict should be. Even less, as attr are implemented asdict,
there shouldn't even be a performance loss. What do you think, list members?]


From alan.gauld at btinternet.com  Thu Dec  4 00:20:16 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 3 Dec 2008 23:20:16 -0000
Subject: [Tutor] using windows wide proxy settings
References: <gh6uo4$b30$1@ger.gmane.org>
Message-ID: <gh747h$uca$1@ger.gmane.org>


"Tim Michelsen" <timmichelsen at gmx-topmail.de> wrote

> is there any possibility in python to retrieve the system wide 
> internet connection settings?

Not as such, but Python does provide the hooks to get it from the OS.

> I would like to access the proxy settings stored in
> Internet Explorer -> Extras -> Options -> Connection -> LAN 
> settings.

Assuming IE implies Windows and not MacOS you can read the
registry using the Windows API or alternativey you can use
Windows Script Host and access it via the Registry object.
In either case you will need the Pythonwin extensions or ctypes.

Its also possible to get at most(all?) of what you need via the
subprocess module and the Windows command line tools.

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Thu Dec  4 00:23:03 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 3 Dec 2008 23:23:03 -0000
Subject: [Tutor] using windows wide proxy settings
References: <gh6uo4$b30$1@ger.gmane.org>
Message-ID: <gh74co$ush$1@ger.gmane.org>


"Tim Michelsen" <timmichelsen at gmx-topmail.de> wrote

> is there any possibility in python to retrieve the system wide 
> internet connection settings?

Further to my earlier mail I had a thought and sure enough there is a
winreg module that makes accessing the registry much easier direct
from Python. Now all you need to do is find the right keys in the
registry... and ninternet search shild throw it up or just search for
a key definition using regedit..

Batteries included...

Alan G 



From john at fouhy.net  Thu Dec  4 00:35:03 2008
From: john at fouhy.net (John Fouhy)
Date: Thu, 4 Dec 2008 12:35:03 +1300
Subject: [Tutor] using windows wide proxy settings
In-Reply-To: <gh6uo4$b30$1@ger.gmane.org>
References: <gh6uo4$b30$1@ger.gmane.org>
Message-ID: <5e58f2e40812031535lc402c44s652b3f87fabef436@mail.gmail.com>

On 04/12/2008, Tim Michelsen <timmichelsen at gmx-topmail.de> wrote:
> Hello,
>  is there any possibility in python to retrieve the system wide internet
> connection settings?
>
>  I would like to access the proxy settings stored in
>  Internet Explorer -> Extras -> Options -> Connection -> LAN settings.

Install pythonwin, then look here:

http://www.microsoft.com/technet/scriptcenter/scripts/python/network/client/list/nwlspy02.mspx?mfr=true

General Microsoft Windows python script repository:
http://www.microsoft.com/technet/scriptcenter/scripts/python/default.mspx?mfr=true

HTH!

-- 
John.

From mwalsh at mwalsh.org  Thu Dec  4 00:37:49 2008
From: mwalsh at mwalsh.org (Martin Walsh)
Date: Wed, 03 Dec 2008 17:37:49 -0600
Subject: [Tutor] using windows wide proxy settings
In-Reply-To: <gh6uo4$b30$1@ger.gmane.org>
References: <gh6uo4$b30$1@ger.gmane.org>
Message-ID: <4937184D.8060304@mwalsh.org>

Tim Michelsen wrote:
> Hello,
> is there any possibility in python to retrieve the system wide internet
> connection settings?
> 
> I would like to access the proxy settings stored in
> Internet Explorer -> Extras -> Options -> Connection -> LAN settings.

I wouldn't believe it if I didn't just see it work this way, but... On
windows, proxy settings configured the way you describe above (if no
auth is required) are retrieved from the registry and used automatically
by urllib(2).urlopen.

from the urllib docs, http://www.python.org/doc/2.5.2/lib/module-urllib.html
"""
The urlopen() function works transparently with proxies which do not
require authentication. In a Unix or Windows environment, set the
http_proxy, ftp_proxy or gopher_proxy environment variables to a URL
that identifies the proxy server before starting the Python interpreter.
For example (the "%" is the command prompt):

...

In a Windows environment, if no proxy environment variables are set,
proxy settings are obtained from the registry's Internet Settings section.
"""

The urllib and urllib2 modules also provide a helper function for
retrieving proxy info...

>>> import urllib2
>>> urllib2.getproxies()
{'ftp': 'ftp://10.0.0.100:8888', 'http': 'http://10.0.0.100:8888'}

HTH,
Marty

From lawrence.wickline at gmail.com  Thu Dec  4 01:58:14 2008
From: lawrence.wickline at gmail.com (Lawrence Wickline)
Date: Wed, 3 Dec 2008 16:58:14 -0800
Subject: [Tutor] Sorting a dictionary on a value in a list.
In-Reply-To: <8191FB37-C507-446C-933F-246C5073689D@gmail.com>
References: <8191FB37-C507-446C-933F-246C5073689D@gmail.com>
Message-ID: <f90615120812031658g6b49d229y1b60cefc3d9f89b4@mail.gmail.com>

I am working on a reducer that needs to produce a sorted output of files
sorted on their overall bandwidth use.  I create a dictionary with the file
name as the key (it is always unique) and in the values I am populating a
list with the two values of bytes and bytes sent.

Each entry looks like {filename:[bytes, bytes_sent]}

how would I sort on bytes sent?
how would I make this more efficient?

code:

# Expect as input:
#      URI,1,return_code,bytes,referer,ip,time_taken,bytes_sent,ref_dom
# index 0  1       2       3      4    5      6           7        8

import sys


dict = {}

def update_dict(filename, bytes, bytes_sent):
   # Build and update our dictionary adding total bytes sent.
   if dict.has_key(filename):
       bytes_sent += dict[filename][1]
       dict[filename] = [bytes, bytes_sent]
   else:
       dict[filename] = [bytes, bytes_sent]

# input comes from STDIN
for line in sys.stdin:
   # remove leading and trailing whitespace and split on tab
   words = line.rstrip().split('\t')
   file = words[0]
   bytes = words[3]
   bytes_sent = int(words[7])
   update_dict(file, bytes, bytes_sent)
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From michele.alzetta at gmail.com  Thu Dec  4 02:03:03 2008
From: michele.alzetta at gmail.com (Michele Alzetta)
Date: Thu, 4 Dec 2008 02:03:03 +0100
Subject: [Tutor] Graph theory
Message-ID: <8079280b0812031703l6beeaf16t6cd57334b5d2e6b7@mail.gmail.com>

Hallo all! It's a long time since I last wrote here.

I have been thinking about a problem, and I'm wondering what the best
approach for a pythonic solution would be.
The actual problem is very complex, but the very first step in the
solution would be to come up with a simple way of handling graphs.

For example, given that:
Definition 1: A network is a figure made up of points (vertices)
connected by non-intersecting curves (arcs).
Definition 2: A vertex is called odd if it has an odd number of arcs
leading to it, other wise it is called even.
Definition 3: An Euler path is a continuous path that passes through
every arc once and only once.

Given the following theorems:
Theorem 1: If a network has more than two odd vertices, it does not
have an Euler path.
Theorem 2: If a network has two or zero odd vertices, it has at least
one Euler path. In particular, if a network has exactly two odd
vertices, then its Euler paths can only start on one of the odd
vertices, and end on the other --  (Euler circuit).

Which would be the best approach for representing figures such as
those found here (  http://mathforum.org/isaac/problems/bridges2.html
) such that one could elaborate a script capable of finding and
describing paths in the figure? For example, Euler paths.

I realize that it is quite feasable to do this, but would take a lot
of coding - vertices and arcs could be represented as instances of
respective classes, and so forth.
But is there an elegant and simple solution already out there?

-- 
Michele Alzetta

From john at fouhy.net  Thu Dec  4 02:16:56 2008
From: john at fouhy.net (John Fouhy)
Date: Thu, 4 Dec 2008 14:16:56 +1300
Subject: [Tutor] Graph theory
In-Reply-To: <8079280b0812031703l6beeaf16t6cd57334b5d2e6b7@mail.gmail.com>
References: <8079280b0812031703l6beeaf16t6cd57334b5d2e6b7@mail.gmail.com>
Message-ID: <5e58f2e40812031716u2aa5b4a5ide2d1f743534f7f@mail.gmail.com>

On 04/12/2008, Michele Alzetta <michele.alzetta at gmail.com> wrote:
>  I have been thinking about a problem, and I'm wondering what the best
>  approach for a pythonic solution would be.
>  The actual problem is very complex, but the very first step in the
>  solution would be to come up with a simple way of handling graphs.

Interestingly, Guido wrote an essay on implementing graphs in python
using dictionaries and lists:

http://python.org/doc/essays/graphs/

I'm sure if you googled around you will be able to find more
full-featured graph libraries (unless, of course, building your own is
part of the attraction :-) ).

-- 
John.

From kent37 at tds.net  Thu Dec  4 02:42:47 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 3 Dec 2008 20:42:47 -0500
Subject: [Tutor] Sorting a dictionary on a value in a list.
In-Reply-To: <f90615120812031658g6b49d229y1b60cefc3d9f89b4@mail.gmail.com>
References: <8191FB37-C507-446C-933F-246C5073689D@gmail.com>
	<f90615120812031658g6b49d229y1b60cefc3d9f89b4@mail.gmail.com>
Message-ID: <1c2a2c590812031742m57ed6f0av1b34fa8f6331a548@mail.gmail.com>

On Wed, Dec 3, 2008 at 7:58 PM, Lawrence Wickline
<lawrence.wickline at gmail.com> wrote:

> how would I sort on bytes sent?

You can't actually sort a dictionary; what you can do is sort the list of items.

In this case each item will look be a tuple
  (filename, (bytes, bytes_sent))
and dict.items() will be a list of such tuples.

The best way to sort a list is to make a key function that extracts a
key from a list item, then pass that to the list sort() method. In
your case, you want to extract the second element of the second
element, so you could use the function
def make_key(item):
  return item[1][1]

Then you can make a sorted list with
sorted(dict.items(), key=make_key)

> how would I make this more efficient?

It looks pretty good to me. A few minor notes below.

> code:
>
> # Expect as input:
> #      URI,1,return_code,bytes,referer,ip,time_taken,bytes_sent,ref_dom
> # index 0  1       2       3      4    5      6           7        8
>
> import sys
>
>
> dict = {}

Don't use dict as the name of a variable, it shadows the built-in
dict() function.

> def update_dict(filename, bytes, bytes_sent):
>    # Build and update our dictionary adding total bytes sent.
>    if dict.has_key(filename):
>        bytes_sent += dict[filename][1]
>        dict[filename] = [bytes, bytes_sent]
>    else:
>        dict[filename] = [bytes, bytes_sent]

If you really want to squeeze every bit of speed,
  filename in dict
is probably faster than
  dict.has_key(filename)
and you might try also using a try / catch block instead of has_key().
You could also try passing dict as a parameter, that might be faster
than having it as a global.

None of these will matter unless you have many thousand lines of
input. How many lines do you have? How long does it take to process?

> # input comes from STDIN
> for line in sys.stdin:
>    # remove leading and trailing whitespace and split on tab
>    words = line.rstrip().split('\t')

rstrip() removes only trailing white space. It is not needed since you
don't use the last field anyway.

>    file = words[0]
>    bytes = words[3]
>    bytes_sent = int(words[7])
>    update_dict(file, bytes, bytes_sent)

If you put all this into a function it will run a little faster.

Kent

From kent37 at tds.net  Thu Dec  4 02:46:21 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 3 Dec 2008 20:46:21 -0500
Subject: [Tutor] using windows wide proxy settings
In-Reply-To: <4937184D.8060304@mwalsh.org>
References: <gh6uo4$b30$1@ger.gmane.org> <4937184D.8060304@mwalsh.org>
Message-ID: <1c2a2c590812031746t5da5dd00g1b35bb53bfcf7f79@mail.gmail.com>

On Wed, Dec 3, 2008 at 6:37 PM, Martin Walsh <mwalsh at mwalsh.org> wrote:

> The urllib and urllib2 modules also provide a helper function for
> retrieving proxy info...
>
>>>> import urllib2
>>>> urllib2.getproxies()
> {'ftp': 'ftp://10.0.0.100:8888', 'http': 'http://10.0.0.100:8888'}

And, since urllib is a Python module, you can easily look at the
source to see where it comes from.

Kent

From kent37 at tds.net  Thu Dec  4 02:49:12 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 3 Dec 2008 20:49:12 -0500
Subject: [Tutor] Graph theory
In-Reply-To: <5e58f2e40812031716u2aa5b4a5ide2d1f743534f7f@mail.gmail.com>
References: <8079280b0812031703l6beeaf16t6cd57334b5d2e6b7@mail.gmail.com>
	<5e58f2e40812031716u2aa5b4a5ide2d1f743534f7f@mail.gmail.com>
Message-ID: <1c2a2c590812031749w718bdbb6ybd4d2e844b225278@mail.gmail.com>

On Wed, Dec 3, 2008 at 8:16 PM, John Fouhy <john at fouhy.net> wrote:

> Interestingly, Guido wrote an essay on implementing graphs in python
> using dictionaries and lists:
>
> http://python.org/doc/essays/graphs/

Also googling "python graph" finds many alternatives.

Kent

From jhodgen at asymmetricsupplychain.com  Thu Dec  4 07:21:45 2008
From: jhodgen at asymmetricsupplychain.com (Jim Hodgen)
Date: Wed, 03 Dec 2008 22:21:45 -0800
Subject: [Tutor] Confused about __setitem__
Message-ID: <493776F9.4060403@asymmetricsupplychain.com>

I am learning Python with a  minesweeper-engine project.  Future 
activities turn my attention to exploring the use of dictionaries as 
sparse matrices, hence the representation of the gameboard.  
Why can't I fill the dictionary-as-a-matrix with an instance of class 
Square?  Why do I need a custom method to make the assignment?  What am 
I not understanding?

*_# basics module (mineswobj1)contents..._*
class Square:
    mined = True              # False if empty, True if mined, no other 
values allowed
    marked = 0                # False if 0, marked-as-mined if 1, 
marked-as-unknown if 2, no other values allowed
    displaystate = 0         # covered if 0, marked if 1, exposed if 2, 
selected if 3, no other values allowed
    minedneighbors = 0  # number of mined neighboring squares, max legit 
value = 8
 
class Baseboard:
    xdimension = 0           # x-dimension of the gameboard, integer 
value greater than 0
    ydimension = 0          # y-dimension of the gameboard, integer 
value greater than 0
    minenumber = 0        # number of mines on the board for play, value 
from 0 to (xdimension * ydimension)
    state = 0                   # playable if 0, not-playable-exploded 
if 1, not-playable-solved if 2
    boardsquares = {}   # dictionary used to emulate an addressable 2 
dimensional grid where an instance of class Square
                                   # is inserted with a key consisting 
of a tuple describing its zero-based address in the grid

def initializeboard(xdim, ydim, minenum):
    gameboard = Baseboard()
    for yct in range(ydim):
        for xct in range(xdim):
            gameboard[(xct,yct)] = Square()
            print 'gameboard[(',xct,yct, ')] =', gameboard[(xct,yct)]

*_# driver module contents_*
import basics

mineswobj1.initializeboard(3, 4, 5)

_*#error message*_
Traceback (most recent call last):
  File "C:\jmh\Python\minedriver0.py", line 6, in <module>
    mineswobj1.initializeboard(3, 4, 5)
  File "C:\jmh\Python\mineswobj1.py", line 26, in initializeboard
    gameboard[(xct,yct)] = Square()
AttributeError: Baseboard instance has no attribute '__setitem__'
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From timmichelsen at gmx-topmail.de  Thu Dec  4 09:26:19 2008
From: timmichelsen at gmx-topmail.de (Timmie)
Date: Thu, 4 Dec 2008 08:26:19 +0000 (UTC)
Subject: [Tutor] using windows wide proxy settings
References: <gh6uo4$b30$1@ger.gmane.org> <4937184D.8060304@mwalsh.org>
	<1c2a2c590812031746t5da5dd00g1b35bb53bfcf7f79@mail.gmail.com>
Message-ID: <loom.20081204T082313-477@post.gmane.org>

Hello all,
thanks a lot for your answers.

> > The urllib and urllib2 modules also provide a helper function for
> > retrieving proxy info...
> >
> >>>> import urllib2
> >>>> urllib2.getproxies()
> > {'ftp': 'ftp://10.0.0.100:8888', 'http': 'http://10.0.0.100:8888'}
This seems to be the fastest method. Very neat.

Since we use pac scripts I refined my search.

Here is another module tailored to this:
http://code.google.com/p/pacparser

There is a python example at the wiki:
http://code.google.com/p/pacparser/wiki/PacFilesInPythonWebclients

It seems that the script can even test if connection is available.
I was looking for this earlier.

KInd regards,
Timmie


From alan.gauld at btinternet.com  Thu Dec  4 09:54:46 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Thu, 4 Dec 2008 08:54:46 -0000
Subject: [Tutor] Confused about __setitem__
References: <493776F9.4060403@asymmetricsupplychain.com>
Message-ID: <gh85so$fsv$1@ger.gmane.org>

"Jim Hodgen" <jhodgen at asymmetricsupplychain.com> wrote

> Why can't I fill the dictionary-as-a-matrix with an instance of 
> class
> Square?

You can but you are not trying to do that in your code.
You are assigning Square to the class that contains the
dictionary, not the dictionary itself.

> class Square:
>     mined = True              # False if empty, True if mined, no 
> other
>     marked = 0                # False if 0, marked-as-mined if 1,
>     displaystate = 0         # covered if 0, marked if 1, exposed if 
> 2,
>     minedneighbors = 0  # number of mined neighboring squares, max 
> legit

These are all class level variables so they will be shared if you
create more than one instance of the class. That's probably
not what you want?. You should initialise them inside an __init__
method if you want each square to have its own values.

> class Baseboard:
>    boardsquares = {}   # dictionary used to emulate an addressable 2

boardsquares is the dictionary not Baseboard

> def initializeboard(xdim, ydim, minenum):
>    gameboard = Baseboard()
>    for yct in range(ydim):
>        for xct in range(xdim):
>            gameboard[(xct,yct)] = Square()

So this needs to be

gameboard.boardsquares[(xct,yct)] = Square()

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From kent37 at tds.net  Thu Dec  4 12:39:08 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 4 Dec 2008 06:39:08 -0500
Subject: [Tutor] Confused about __setitem__
In-Reply-To: <gh85so$fsv$1@ger.gmane.org>
References: <493776F9.4060403@asymmetricsupplychain.com>
	<gh85so$fsv$1@ger.gmane.org>
Message-ID: <1c2a2c590812040339r6334004o3a2daed06d7388a7@mail.gmail.com>

On Thu, Dec 4, 2008 at 3:54 AM, Alan Gauld <alan.gauld at btinternet.com> wrote:

> These are all class level variables so they will be shared if you
> create more than one instance of the class. That's probably
> not what you want?. You should initialise them inside an __init__
> method if you want each square to have its own values.

And likewise for the board variables.

Kent

From prasadaraon50 at gmail.com  Thu Dec  4 15:46:04 2008
From: prasadaraon50 at gmail.com (prasad rao)
Date: Thu, 4 Dec 2008 20:16:04 +0530
Subject: [Tutor] To print docstrings
Message-ID: <9e3fac840812040646i39257f4dw36d80c4243e7dee7@mail.gmail.com>

Hello  friends.
 I am new to programing.I am learning Python.
I failed in my attempts to retrive doc strings of methods in
a module.
"""
for x in dir(logging):
 print x,x.__doc__
 =============
for x in dir(collections):
 print x,collections.x.__doc__
==================

>>> def dd(o):
 zx=dir (o)
 for x in zx:
  ax=o+x
  print ax.__doc__


>>> dd(collections)

================

def dd(o):
 zx=dir (o)
 for x in zx:
  ax=str(o)+x

  print ax.__doc__


>>>
>>> dd(collections)

"""

Above snippets of code generates str.__doc__ for every iteration.

Please someone tell me how I can retrive all the docstrings

ina module

thanks in advance

 Prasad
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From a.t.hofkamp at tue.nl  Thu Dec  4 16:10:45 2008
From: a.t.hofkamp at tue.nl (A.T.Hofkamp)
Date: Thu, 04 Dec 2008 16:10:45 +0100
Subject: [Tutor] To print docstrings
In-Reply-To: <9e3fac840812040646i39257f4dw36d80c4243e7dee7@mail.gmail.com>
References: <9e3fac840812040646i39257f4dw36d80c4243e7dee7@mail.gmail.com>
Message-ID: <4937F2F5.5070800@tue.nl>

prasad rao wrote:
> Hello  friends.
>  I am new to programing.I am learning Python.
> I failed in my attempts to retrive doc strings of methods in
> a module.
> """
> for x in dir(logging):
>  print x,x.__doc__
>  =============
> for x in dir(collections):
>  print x,collections.x.__doc__
> ==================

I am not sure what you are aiming for. If you just want to collect them for 
reading, http://docs.python.org/library/ is much easier.

If you want to produce documentation of your own modules, you may want to take 
a look at pydoc or epydoc.


If you want to collect the doc strings just for the sake of it, add them in a 
list instead of printing:

docs = []
for x in dir(collections):
    docs.append(x.__doc__)

or in one line:  docs = [x.__doc__ for x in dir(collections)]


if you want to make a single (possibly long string of text from that list, 
join the strings together as in

text = "\n".join(docs)


or all in one line (with a generator to suppress creation of the intermediate 
list):

text = "\n".join(x.__doc__ for x in dir(collections))

>>>> def dd(o):
>  zx=dir (o)
>  for x in zx:
>   ax=o+x
>   print ax.__doc__
> 

I have no idea what you are doing with 'ax' here.
You seem to be adding a module and one of its functions and assign the result 
to ax, an operation I don't understand.

If it is important for you, could you please provide some explanation of what 
you trying to do here?


Sincerely,
Albert

From kent37 at tds.net  Thu Dec  4 16:17:50 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 4 Dec 2008 10:17:50 -0500
Subject: [Tutor] To print docstrings
In-Reply-To: <9e3fac840812040646i39257f4dw36d80c4243e7dee7@mail.gmail.com>
References: <9e3fac840812040646i39257f4dw36d80c4243e7dee7@mail.gmail.com>
Message-ID: <1c2a2c590812040717q2225ef98n422e441e79dae946@mail.gmail.com>

On Thu, Dec 4, 2008 at 9:46 AM, prasad rao <prasadaraon50 at gmail.com> wrote:
>
> Hello  friends.
>  I am new to programing.I am learning Python.
> I failed in my attempts to retrive doc strings of methods in
> a module.
> """
> for x in dir(logging):
>  print x,x.__doc__

Here x is a string, that is why you print out str.__doc__. Try this:
  print x, getattr(logging, x).__doc__

or, just
  help(logging)

Kent

From kent37 at tds.net  Thu Dec  4 16:42:51 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 4 Dec 2008 10:42:51 -0500
Subject: [Tutor] To print docstrings
In-Reply-To: <4937F2F5.5070800@tue.nl>
References: <9e3fac840812040646i39257f4dw36d80c4243e7dee7@mail.gmail.com>
	<4937F2F5.5070800@tue.nl>
Message-ID: <1c2a2c590812040742j6ea3a449p9ee2ed07c040ecf@mail.gmail.com>

On Thu, Dec 4, 2008 at 10:10 AM, A.T.Hofkamp <a.t.hofkamp at tue.nl> wrote:

> docs = []
> for x in dir(collections):
>   docs.append(x.__doc__)

This will not work, see my previous email for solution.

Kent

From bgailer at gmail.com  Thu Dec  4 17:23:57 2008
From: bgailer at gmail.com (bob gailer)
Date: Thu, 04 Dec 2008 11:23:57 -0500
Subject: [Tutor] Confused about __setitem__
In-Reply-To: <493776F9.4060403@asymmetricsupplychain.com>
References: <493776F9.4060403@asymmetricsupplychain.com>
Message-ID: <4938041D.10508@gmail.com>

Jim Hodgen wrote:
> I am learning Python with a  minesweeper-engine project.  Future 
> activities turn my attention to exploring the use of dictionaries as 
> sparse matrices, hence the representation of the gameboard.  
> Why can't I fill the dictionary-as-a-matrix with an instance of class 
> Square?  Why do I need a custom method to make the assignment?  What 
> am I not understanding?
You don't have a sparse matrix here. There is a dictionary entry for 
every square. You might as well use a nested list or an array from one 
of the array modules.

If you want a Baseboard instance to directly accept keyed assignment use:

class Basebaord(dict)

and drop boardsquares.
>
> *_# basics module (mineswobj1)contents..._*
> class Square:
>     mined = True              # False if empty, True if mined, no 
> other values allowed
>     marked = 0                # False if 0, marked-as-mined if 1, 
> marked-as-unknown if 2, no other values allowed
>     displaystate = 0         # covered if 0, marked if 1, exposed if 
> 2, selected if 3, no other values allowed

marked and display state are in conflict and overlap. Consider instead:
    selected = False
    displaystate is one of covered-blank, covered-marked, mined, exposed
>     minedneighbors = 0  # number of mined neighboring squares, max 
> legit value = 8
>  
> class Baseboard:
>     xdimension = 0           # x-dimension of the gameboard, integer 
> value greater than 0
>     ydimension = 0          # y-dimension of the gameboard, integer 
> value greater than 0
>     minenumber = 0        # number of mines on the board for play, 
> value from 0 to (xdimension * ydimension)
>     state = 0                   # playable if 0, not-playable-exploded 
> if 1, not-playable-solved if 2
>     boardsquares = {}   # dictionary used to emulate an addressable 2 
> dimensional grid where an instance of class Square
>                                    # is inserted with a key consisting 
> of a tuple describing its zero-based address in the grid
>
> def initializeboard(xdim, ydim, minenum):
>     gameboard = Baseboard()
>     for yct in range(ydim):
>         for xct in range(xdim):
>             gameboard[(xct,yct)] = Square()
>             print 'gameboard[(',xct,yct, ')] =', gameboard[(xct,yct)]
>
> *_# driver module contents_*
> import basics
>
> mineswobj1.initializeboard(3, 4, 5)
>
> _*#error message*_
> Traceback (most recent call last):
>   File "C:\jmh\Python\minedriver0.py", line 6, in <module>
>     mineswobj1.initializeboard(3, 4, 5)
>   File "C:\jmh\Python\mineswobj1.py", line 26, in initializeboard
>     gameboard[(xct,yct)] = Square()
> AttributeError: Baseboard instance has no attribute '__setitem__'
> ------------------------------------------------------------------------
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From joewoe at fsmail.de  Thu Dec  4 17:38:41 2008
From: joewoe at fsmail.de (=?utf-8?Q?J=F6rg_W=F6lke?=)
Date: Thu, 4 Dec 2008 17:38:41 +0100
Subject: [Tutor] Help Optimise Code
In-Reply-To: <f0b4202b0811190513k724fe25yc1666d2e41ad32df@mail.gmail.com>
References: <f0b4202b0811190513k724fe25yc1666d2e41ad32df@mail.gmail.com>
Message-ID: <20081204163841.GA6274@localhost>

* Richard Lovely <roadierich at googlemail.com> [081123 11:35]:
> I've tried a the sieve of erath-whatever as in test_generator,
> implemented using itertools functions, but it hit max recusion depth
> somewhere before 1000 primes, and I'm after millions of primes.

I found an old implementation for some exercise of the 
"sieve of Eratosthenes" in my backups and its not recursive but 
iterative:

#!/usr/bin/env python

l=10000*[1]
for i in range(2,len(l)):
    if l[i] == 1:
       print i
           for j in range(i+1,len(l)):
               if j%i == 0:
                   l[j]=0

Yes, it is pretty slow for a range of a million, but it speeds up 
a little after half an hour or so :-)
You might want to have a look at the bsd-games package, which
includes a program named primes. It prints out primes at a 
reasonable speed - up to 4294967295 (the default). The manpage says:
"
BUGS
     primes won't get you a world record.
"
If you can get it to work faster in python? I doubt that.
primes uses IIRC atkin-sieve: "http://cr.yp.to/papers/primesieves.pdf"

-- 
You have an ambitious nature and may make a name for yourself.


From kent37 at tds.net  Thu Dec  4 19:10:39 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 4 Dec 2008 13:10:39 -0500
Subject: [Tutor] Help Optimise Code
In-Reply-To: <20081204163841.GA6274@localhost>
References: <f0b4202b0811190513k724fe25yc1666d2e41ad32df@mail.gmail.com>
	<20081204163841.GA6274@localhost>
Message-ID: <1c2a2c590812041010n31c69e6evd1dc06af728c400f@mail.gmail.com>

On Thu, Dec 4, 2008 at 11:38 AM, J?rg W?lke <joewoe at fsmail.de> wrote:

> #!/usr/bin/env python
>
> l=10000*[1]
> for i in range(2,len(l)):
>    if l[i] == 1:
>       print i
>           for j in range(i+1,len(l)):
>               if j%i == 0:

for j in range(2*i, len(l), i):
would be much faster, avoiding all the division.

Kent

From alan.gauld at btinternet.com  Thu Dec  4 19:27:12 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Thu, 4 Dec 2008 18:27:12 -0000
Subject: [Tutor] To print docstrings
References: <9e3fac840812040646i39257f4dw36d80c4243e7dee7@mail.gmail.com>
Message-ID: <gh97dv$5k0$1@ger.gmane.org>


"prasad rao" <prasadaraon50 at gmail.com> wrote 

> Please someone tell me how I can retrive all the docstrings
> in a module

Unless its just as an exercise use help()
Its much easier!


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


From lawrence.wickline at gmail.com  Thu Dec  4 19:48:54 2008
From: lawrence.wickline at gmail.com (Lawrence Wickline)
Date: Thu, 4 Dec 2008 10:48:54 -0800
Subject: [Tutor] Sorting a dictionary on a value in a list.
In-Reply-To: <1c2a2c590812031742m57ed6f0av1b34fa8f6331a548@mail.gmail.com>
References: <8191FB37-C507-446C-933F-246C5073689D@gmail.com>
	<f90615120812031658g6b49d229y1b60cefc3d9f89b4@mail.gmail.com>
	<1c2a2c590812031742m57ed6f0av1b34fa8f6331a548@mail.gmail.com>
Message-ID: <045316B5-CB8D-4C92-9CA4-E23FC5B3B08D@gmail.com>

Thanks for the help I think I got it.

As far as lines go I believe it will be processing hundreds of  
thousands of lines if not a million or more lines per run. I haven't  
gotten to do a full run but it has been running acceptably fast on my  
test files.

I ended up putting it into a main function and adding:

if __name__ == "__main__":
    main()



On Dec 3, 2008, at 5:42 PM, Kent Johnson wrote:

> On Wed, Dec 3, 2008 at 7:58 PM, Lawrence Wickline
> <lawrence.wickline at gmail.com> wrote:
>
>> how would I sort on bytes sent?
>
> You can't actually sort a dictionary; what you can do is sort the  
> list of items.
>
> In this case each item will look be a tuple
> (filename, (bytes, bytes_sent))
> and dict.items() will be a list of such tuples.
>
> The best way to sort a list is to make a key function that extracts a
> key from a list item, then pass that to the list sort() method. In
> your case, you want to extract the second element of the second
> element, so you could use the function
> def make_key(item):
> return item[1][1]
>
> Then you can make a sorted list with
> sorted(dict.items(), key=make_key)
>
>> how would I make this more efficient?
>
> It looks pretty good to me. A few minor notes below.
>
>> code:
>>
>> # Expect as input:
>> #      URI, 
>> 1,return_code,bytes,referer,ip,time_taken,bytes_sent,ref_dom
>> # index 0  1       2       3      4    5      6           7        8
>>
>> import sys
>>
>>
>> dict = {}
>
> Don't use dict as the name of a variable, it shadows the built-in
> dict() function.
>
>> def update_dict(filename, bytes, bytes_sent):
>>  # Build and update our dictionary adding total bytes sent.
>>  if dict.has_key(filename):
>>      bytes_sent += dict[filename][1]
>>      dict[filename] = [bytes, bytes_sent]
>>  else:
>>      dict[filename] = [bytes, bytes_sent]
>
> If you really want to squeeze every bit of speed,
> filename in dict
> is probably faster than
> dict.has_key(filename)
> and you might try also using a try / catch block instead of has_key().
> You could also try passing dict as a parameter, that might be faster
> than having it as a global.
>
> None of these will matter unless you have many thousand lines of
> input. How many lines do you have? How long does it take to process?
>
>> # input comes from STDIN
>> for line in sys.stdin:
>>  # remove leading and trailing whitespace and split on tab
>>  words = line.rstrip().split('\t')
>
> rstrip() removes only trailing white space. It is not needed since you
> don't use the last field anyway.
>
>>  file = words[0]
>>  bytes = words[3]
>>  bytes_sent = int(words[7])
>>  update_dict(file, bytes, bytes_sent)
>
> If you put all this into a function it will run a little faster.
>
> Kent


From dkuhlman at rexx.com  Thu Dec  4 22:26:02 2008
From: dkuhlman at rexx.com (Dave Kuhlman)
Date: Thu, 4 Dec 2008 13:26:02 -0800
Subject: [Tutor] Graph theory
In-Reply-To: <1c2a2c590812031749w718bdbb6ybd4d2e844b225278@mail.gmail.com>
References: <8079280b0812031703l6beeaf16t6cd57334b5d2e6b7@mail.gmail.com>
	<5e58f2e40812031716u2aa5b4a5ide2d1f743534f7f@mail.gmail.com>
	<1c2a2c590812031749w718bdbb6ybd4d2e844b225278@mail.gmail.com>
Message-ID: <20081204212602.GA37329@cutter.rexx.com>

On Wed, Dec 03, 2008 at 08:49:12PM -0500, Kent Johnson wrote:
> On Wed, Dec 3, 2008 at 8:16 PM, John Fouhy <john at fouhy.net> wrote:
> 
> > Interestingly, Guido wrote an essay on implementing graphs in python
> > using dictionaries and lists:
> >
> > http://python.org/doc/essays/graphs/
> 
> Also googling "python graph" finds many alternatives.

And, if you are also interested in the visual display of graphs,
then look for graphviz and python-pygraphviz.

- Dave

-- 
Dave Kuhlman
http://www.rexx.com/~dkuhlman

From santiagopm at wanadoo.es  Fri Dec  5 00:05:51 2008
From: santiagopm at wanadoo.es (=?UTF-8?Q?Santiago_Pay=C3=A0_i_Miralta?=)
Date: Fri, 5 Dec 2008 00:05:51 +0100
Subject: [Tutor] Graph theory
In-Reply-To: <20081204212602.GA37329@cutter.rexx.com>
References: <8079280b0812031703l6beeaf16t6cd57334b5d2e6b7@mail.gmail.com>
	<5e58f2e40812031716u2aa5b4a5ide2d1f743534f7f@mail.gmail.com>
	<1c2a2c590812031749w718bdbb6ybd4d2e844b225278@mail.gmail.com>
	<20081204212602.GA37329@cutter.rexx.com>
Message-ID: <20081204230551.GA28416@gorda.chocita>

On Thu, Dec 04, 2008 at 01:26:02PM -0800, Dave Kuhlman wrote:
> On Wed, Dec 03, 2008 at 08:49:12PM -0500, Kent Johnson wrote:
> > On Wed, Dec 3, 2008 at 8:16 PM, John Fouhy <john at fouhy.net> wrote:
> > 
> > > Interestingly, Guido wrote an essay on implementing graphs in python
> > > using dictionaries and lists:
> > >
> > > http://python.org/doc/essays/graphs/
> > 
> > Also googling "python graph" finds many alternatives.
> 
> And, if you are also interested in the visual display of graphs,
> then look for graphviz and python-pygraphviz.
> 

Networkx works fine for me. Try it!

http://networkx.lanl.gov/

Santiago

-- 
Santiago Pay? i Miralta
607 070 992
mailto:santiagopm at wanadoo.es

From jeremiah.jester at panasonic.aero  Fri Dec  5 02:25:39 2008
From: jeremiah.jester at panasonic.aero (Jeremiah Jester)
Date: Thu, 04 Dec 2008 17:25:39 -0800
Subject: [Tutor] rrdtool examples.
Message-ID: <1228440339.19777.21.camel@M13425>

Is anyone on here using the python-rrdtool module for graphing and
analysis? If so, do you have some sample scripts you could show me.
There doesn't seem to be a lot out there as far as real world python
examples.

Thanks,
JJ



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From mortimerp at live.com  Fri Dec  5 09:51:45 2008
From: mortimerp at live.com (Marty Pitts)
Date: Fri, 5 Dec 2008 00:51:45 -0800
Subject: [Tutor] Writing to a file problem....
Message-ID: <BLU120-W47BE3ADEFE5628D1C56DDBC4FE0@phx.gbl>


Hi,

I am currently working my way through the .pdf Byte of Python tutorial by Swaroop, C H

After about 1/2 way I ran into a problem that my own trouble shooting has failed :-(.

The script created is for backing up files into a .zip format.  It is written by the 
author in a *nix environment. However, I am currently on a *doz box. I have made certain
changes in order for it to play nice with Windows, but I am still stumped.

Here is the script:

#!c:\python26\python.exe
# Filename : backup_ver1.py

import os
import time

#1. The files and directories to be backed up are specified in a list
source = ['c:\Users\Marty\Downloads', 'c:\Users\Marty\Contacts']

#2. The backup must be stored in a main backup directory
target_dir = 'J:\\backup\\'

#3. The files are backed up into a zip file.
#4. The name of the zip archive is the current date and time
target = target_dir + time.strftime('%Y%m%d%H%M%S') + '.zip'

#5. We use the zip command to put files in a zip archive
zip_command = "c:\Users\Marty\Zip\Zip -!rv '%s' %s" % (target, ' '.join(source))

# Run the backup
if os.system(zip_command) == 0:
    print 'Sucessful backup to', target
else:
    print 'Backup FAILED'

The error I get running the script from a command prompt is: 
C:\Python26>backup_ver1.py
zip I/O error: Invalid argument

zip error: Could not create output file ('J:/backup/20081205002535.zip')
Backup FAILED

>From what I can tell, it might be a problem writing the file in Windows.
Maybe a rights issue.  I don't know.  I have tried granting the folder
all the write rights I could think of.

If I change the target_dir to just 'j:' I then get the zip program appearing
to run through all the files compressing them, but I end up with this msg:

total bytes=104598424, compressed=102594319 ->2% savings
   zip warning: new zip file left as 'J:zia03824
zip I/O error: Invalid argument

zip error: Could not create output file (was replacing the original zip file)
Backup FAILED


Any suggestions would be appreciated.

Thanks,

Marty.

_________________________________________________________________
Send e-mail faster without improving your typing skills.
http://windowslive.com/Explore/hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_speed_122008

From wescpy at gmail.com  Fri Dec  5 10:37:56 2008
From: wescpy at gmail.com (wesley chun)
Date: Fri, 5 Dec 2008 01:37:56 -0800
Subject: [Tutor] Writing to a file problem....
In-Reply-To: <BLU120-W47BE3ADEFE5628D1C56DDBC4FE0@phx.gbl>
References: <BLU120-W47BE3ADEFE5628D1C56DDBC4FE0@phx.gbl>
Message-ID: <78b3a9580812050137g1447cddet91f8325f41b49a22@mail.gmail.com>

marty,

i applaud you in your efforts to port this script to the Win32
platform. the task is not as simple as one may expect, due to the
differing file pathname nomenclatures that the different operating
systems use.

because of this, i have a couple of suggestions:

1. highly recommend converting this script to use the built-in ZIP
file support offered by Python via the zipfile module:
http://docs.python.org/lib/module-zipfile.html

2. instead of filenames like: 'c:\Users\Marty\Downloads',
'c:\Users\Marty\Contacts',  'J:\\backup\\', etc., i would recommend
using "raw strings." these will help deal with the backward slashes.
in the 3rd example, you correctly use double-backslashes, but you
don't in the 1st pair.  for all 3, change all the files to single
backslashes and place an "r" preceding the opening quote, i.e.,
r'c:\Users\Marty\Downloads', r'c:\Users\Marty\Contacts', r'J:\backup'.
for the last case where you are using a directory/folder name, use
os.path.join() instead of manually placing the filepath separator.

if you combine these together, you should be able to rework your
script so that things work properly without having to use external
calls like os.system().

hope these help!
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2007,2001
"Python Fundamentals", Prentice Hall, (c)2009
    http://corepython.com

wesley.j.chun :: wescpy-at-gmail.com
python training and technical consulting
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com

From webmaster at mikehoy.net  Fri Dec  5 11:49:21 2008
From: webmaster at mikehoy.net (Mike Hoy)
Date: Fri, 5 Dec 2008 03:49:21 -0700
Subject: [Tutor] Jython question
Message-ID: <ca1a85bc0812050249l25799537g34070f976bb50754@mail.gmail.com>

Is this the right forum to ask a jython question?

I want to get started on using GUI with my python apps and I already
study Java so I thought maybe I should combine the two. I did some
playing around with it so far and I like what I see. I'll post my code
if you guys handle this.

Any thoughts?

-- 
Mike Hoy

From kent37 at tds.net  Fri Dec  5 12:46:25 2008
From: kent37 at tds.net (Kent Johnson)
Date: Fri, 5 Dec 2008 06:46:25 -0500
Subject: [Tutor] Writing to a file problem....
In-Reply-To: <BLU120-W47BE3ADEFE5628D1C56DDBC4FE0@phx.gbl>
References: <BLU120-W47BE3ADEFE5628D1C56DDBC4FE0@phx.gbl>
Message-ID: <1c2a2c590812050346i10890454o37ee94dcc874ddaa@mail.gmail.com>

On Fri, Dec 5, 2008 at 3:51 AM, Marty Pitts <mortimerp at live.com> wrote:


> #5. We use the zip command to put files in a zip archive
> zip_command = "c:\Users\Marty\Zip\Zip -!rv '%s' %s" % (target, ' '.join(source))

It might help to print zip_command, to make sure it is what you
expect. You can take the printed command and try it on the command
line yourself.

Kent

From TexasJerky100 at aol.com  Thu Dec  4 21:28:49 2008
From: TexasJerky100 at aol.com (TexasJerky100 at aol.com)
Date: Thu, 4 Dec 2008 15:28:49 EST
Subject: [Tutor] Random equation generator
Message-ID: <d25.3e9a3f1f.36699781@aol.com>

I am starting out with 7 fixed reference points.  From  there I want  a 
program that can randomly
generate linear equations.  After the equations are generated I would  then 
like to randomly insert
the 7 fixed reference points into the equations and calculate the  results.  
I currently have several
programs that can generate random string of words from a file that contains  
a list of word but is not
much help creating random equations.
  Do you know if there is such a program that can do what  I am  trying to 
get accomplished??
 
Thanks
 
Frank Hopkins
Houston, Tx
**************Make your life easier with all your friends, email, and 
favorite sites in one place.  Try it now. 
(http://www.aol.com/?optin=new-dp&icid=aolcom40vanity&ncid=emlcntaolcom00000010)
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From roadierich at googlemail.com  Fri Dec  5 14:30:03 2008
From: roadierich at googlemail.com (Rich Lovely)
Date: Fri, 5 Dec 2008 13:30:03 +0000
Subject: [Tutor] Random equation generator
In-Reply-To: <d25.3e9a3f1f.36699781@aol.com>
References: <d25.3e9a3f1f.36699781@aol.com>
Message-ID: <E934B435-FA3C-4A35-96F3-346EA0EBF9AF@googlemail.com>

When you say linear, I'm assuming fitting y=mx+c, and passing through  
points?

The line through points (x1, y1) and (x2,y2) is

y - y1 = (y2-y1) / (x2-x1) * (x-x1)

That multiplies out to:

y = (y2-y1)/(x2-x1) * x - (y2-y1)/(x2-x1) + y1
That gives m = (y2-y1)/(x2-x1) and c =  y1 - (y2-y1)/(x2-x1)

you can then create a class to represent the line:

class Line(object):
     def __init__(self, (x1,y1), (x2,y2)):
         "create a line passing through points (x1,y1) and (x2,y2)  
(inputted as tuples)"
         self.m = (y2-y1)/(x2-x1)
         self.c = y1 - self.m

     def is_on_line(self,(x,y)):
         'Test if point represtented by an (x,y) tuple is on the line"
         if self. m * x + self.c == y:
             return True
         else:
             return False

     def __str__(self):
         "returns the equation of the line in the form y=mx+c.  Might  
be quite long if floats are involved."
         print "y=%dx + %d" % (self.m, self.c)


Then all you have to do is choose a pair of points, then iterate over  
the list, testing each point in turn, wash, rinse and repeat.

Does that help?

On 4 Dec 2008, at 20:28, TexasJerky100 at aol.com wrote:

>    I am starting out with 7 fixed reference points.  From there I  
> want  a program that can randomly
> generate linear equations.  After the equations are generated I  
> would then like to randomly insert
> the 7 fixed reference points into the equations and calculate the  
> results.  I currently have several
> programs that can generate random string of words from a file that  
> contains a list of word but is not
> much help creating random equations.
>   Do you know if there is such a program that can do what  I am  
> trying to get accomplished??
>
> Thanks
>
> Frank Hopkins
> Houston, Tx
>
>
>
> Make your life easier with all your friends, email, and favorite  
> sites in one place. Try it now.
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor

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From nephish at gmail.com  Fri Dec  5 19:05:38 2008
From: nephish at gmail.com (shawn bright)
Date: Fri, 5 Dec 2008 12:05:38 -0600
Subject: [Tutor] best way to run several processes over and over
Message-ID: <384c93600812051005qac907c1ta6d6c684ba19cc52@mail.gmail.com>

Hey all.

I have a rather large app that uses 14 threads that all run at the same time.

i use threading.Thread().start() to set them off.

each one runs somthing like this

def run():
    while 1:
        do a bunch of stuff
         time.sleep(60)

i have the option i guess of having fewer threads, and just calling an
outside script for some of the actions, like this

def run():
    while 1:
        do a bunch of stuff
         time.sleep(60)
         os.system("run_other_scripts.py")

Does one have an advantage over the other?

thanks
shawn

From alan.gauld at btinternet.com  Fri Dec  5 19:29:20 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Fri, 5 Dec 2008 18:29:20 -0000
Subject: [Tutor] best way to run several processes over and over
References: <384c93600812051005qac907c1ta6d6c684ba19cc52@mail.gmail.com>
Message-ID: <ghbrts$fin$1@ger.gmane.org>

"shawn bright" <nephish at gmail.com> wrote
> I have a rather large app that uses 14 threads that all run at the 
> same time.
> each one runs somthing like this
>
> def run():
>    while 1:
>        do a bunch of stuff
>         time.sleep(60)
>
> i have the option i guess of having fewer threads, and just calling 
> an
> outside script for some of the actions, like this
>
> def run():
>    while 1:
>        do a bunch of stuff
>         time.sleep(60)
>         os.system("run_other_scripts.py")
>
> Does one have an advantage over the other?

In general threads use a lot less resource than processes so your
existing approach should be better. BUT the sleep(60)  bothers me
slightly. A one minute delay is an age in computer terms. It might
be better to see if you can build the delay outside the threading
and have each thread run just once then die. Then restart the
threads after 60 seconds at the top level.

But whether that is really any better would require you to try it and
see I suspect. Guessing the effect of these kinds of changes is
little more than speculation...

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From denis.spir at free.fr  Sat Dec  6 08:50:51 2008
From: denis.spir at free.fr (spir)
Date: Sat, 06 Dec 2008 08:50:51 +0100
Subject: [Tutor] Writing to a file problem....
In-Reply-To: <BLU120-W1117633E4BC8AC7719760C4FE0@phx.gbl>
References: <BLU120-W47BE3ADEFE5628D1C56DDBC4FE0@phx.gbl>
	<1c2a2c590812050346i10890454o37ee94dcc874ddaa@mail.gmail.com>
	<4939AFC0.1080206@free.fr>
	<BLU120-W1117633E4BC8AC7719760C4FE0@phx.gbl>
Message-ID: <493A2EDB.7030608@free.fr>

Marty Pitts a ?crit :
> 
> 
>> Date: Fri, 5 Dec 2008 23:48:32 +0100
>> From: denis.spir at free.fr
>> To: mortimerp at live.com
>> Subject: Re: [Tutor] Writing to a file problem....
>>
>>> zip_command = "c:\Users\Marty\Zip\Zip -!rv '%s' %s" % (target, ' '.join(source))
>> What if you just double the '\' -- you did it properly for you "j:\\..." path.
>> denis
> 
> I tried that as well a bunch of variations such as r'j:\Backup\ and 'j:\\Backup\\' and 'j:/Backup/'
> 
> None of which seems to have worked.

Sorry.
Also, is the '!' really a valid part of a zip argument?
Have you tried for a test e.g.

c:\Users\Marty\Zip\Zip -!rv 'test_target' test_source.txt

and

c:\Users\Marty\Zip\Zip -!rv 'test_target' test_source1.txt test_source2.txt

on the command line? (test_sources existing)
If yes, meaning that the overall zip_command format is right, then logially the 
only source of noise precisely is 'source'. Obviously, it must be a sequence of 
valid name files. Try:

print "%s\n%s\n%s" % (
source
, ' '.join(source)
, ( "c:\Users\Marty\Zip\Zip -!rv '%s' %s" % (target, ' '.join(source)) )
)

to really check how you call zip. There must be something wrong, no?
By the way, I just checked the output format above, and it gave me:
c:\Users\Marty\Zip\Zip -!rv 'test.txt' test1.text test2.txt
How come that the target is surrounded with ''? For zip, all of that arg list 
is plain text anyway... Is it necessary for zip to identify target? Or for 
filenames that include spaces? I would try without apostrophes, anyway, and the 
contrary, meaning to quote source list, too:

' '.join([("'%s'" %name) for name in source]) (untested)

(Now, I think that this last version has higher chances to be right, because of 
the space_in_file_name issue. Try to use "", too.)
Hope this helps.

denis


From lie.1296 at gmail.com  Sat Dec  6 09:41:10 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sat, 6 Dec 2008 08:41:10 +0000 (UTC)
Subject: [Tutor] Sorting a dictionary on a value in a list.
References: <8191FB37-C507-446C-933F-246C5073689D@gmail.com>
	<f90615120812031658g6b49d229y1b60cefc3d9f89b4@mail.gmail.com>
	<1c2a2c590812031742m57ed6f0av1b34fa8f6331a548@mail.gmail.com>
	<045316B5-CB8D-4C92-9CA4-E23FC5B3B08D@gmail.com>
Message-ID: <ghddr6$15v$1@ger.gmane.org>

On Thu, 04 Dec 2008 10:48:54 -0800, Lawrence Wickline wrote:

> Thanks for the help I think I got it.
> 
> As far as lines go I believe it will be processing hundreds of thousands
> of lines if not a million or more lines per run. I haven't gotten to do
> a full run but it has been running acceptably fast on my test files.
> 
> I ended up putting it into a main function and adding:
> 
> if __name__ == "__main__":
>     main()
> 

In most cases, in processing involving networking, the bottleneck is the 
network speed itself. To speed things up by optimizing your own code 
might not make your download significantly faster (getting 60 seconds 
faster is great for scripts that usually runs for 70 seconds, but is a 
waste of development time for scripts that usually run for 1 hour)

Usually a multi-threading downloader might be a better chance to 
improvement, especially for 1)  downloading from different site, 2) the 
remote sites have speed limit, 3) you have faster download link than the 
server can gives


From ptmcg at austin.rr.com  Sat Dec  6 10:20:51 2008
From: ptmcg at austin.rr.com (Paul McGuire)
Date: Sat, 6 Dec 2008 03:20:51 -0600
Subject: [Tutor] Random equation generator
In-Reply-To: <mailman.27171.1228549858.3486.tutor@python.org>
References: <mailman.27171.1228549858.3486.tutor@python.org>
Message-ID: <2A737786909B4C99B8ED668074F077C3@AWA2>

I would say, though, that you should be careful in your implementation of
is_on_line, for floating point round-off errors.  Try this at the command
prompt (Python 2.5.2, with __future__ division imported):

>>> 49 * (1/49) == 1
False
>>> 1 - 49 * (1/49)
1.1102230246251565e-016

I would suggest a slightly modified version of is_on_line:

class Line(object):
     EPSILON = 1e-15
     ...

     def is_on_line(self,(x,y)):
         'Test if point represtented by an (x,y) tuple is on the line'
         return abs(self. m * x + self.c - y) < Line.EPSILON

-- Paul



From roadierich at googlemail.com  Sat Dec  6 17:05:42 2008
From: roadierich at googlemail.com (Rich Lovely)
Date: Sat, 6 Dec 2008 16:05:42 +0000
Subject: [Tutor] Random equation generator
In-Reply-To: <c6a.44a1d3ab.366a8c20@aol.com>
References: <c6a.44a1d3ab.366a8c20@aol.com>
Message-ID: <E25AB670-9F04-4CC4-B4D8-4F5159523A2F@googlemail.com>

Please use the reply-all button when responding, so that your message  
gets sent to the list as well.

If that's the sort of equation you're after, than the easiest way  
would probably to decide on a generalised form:
> y=(2x-1)*4x
y = 4*x**2 - 4x
> y=2+5(x-1)
y = 5*x - 3
> y=(2x+5)+(5x-25)
y = 10*x**2 + 75*x - 125

> y=((x+13)/((x-18))*(2x-1)
y = (2*x**2 - 19*x -13) / (x - 18)

Except for the last equation, they are all of the "general form" ax^2  
+bx + c.

These can be generated using tools from the random module:
(pseudo python)
equation = randint(minimum, maximum) * x ** 2 +  
randint(minimum,maximum) * x + randint(minimum,maximum)

if you want to generate equations in the form of the last one you  
mentioned, it will be a bit more difficult.

You could add a random number of terms with a random power, but  
actually impliementing it might be a bit harder:

import random
def generate_terms(minimum, maximum):
     "generate a list of random terms for an equation of the form  
(a*x)**b + ...  "
     return [(random.randint(minimum, maximum), random.randint(-1,1))  
for x in xrange(random.randint(1, 10))]

class Line(object):
     epsilon = 1e-15
     def __init__(self, equation_terms):
         self._equation_terms = equation_terms
     def is_on_line(self, (x,y)):
         calulated_y = sum((a * x) ** b for a,b in self._equation_terms)
         return abs(y - calculated_y) <= self.epsilon #see message  
from Paul

Then, instead of picking two points, you can do:

line = Line(generate_terms(-25, 25))

then proceed as with my previous message.

getting a nice string representation won't be as easy... unless you're  
happy with seeing x**-1's dotted around.

You'll need to tweak the values within the generate_terms function to  
get exactly what you want.


Alternatively (and I'm probably going to get shouted at for suggesting  
it), you could write something that generates random python equations,  
and use some variety of eval() to get a value out of it...

Does that help?

On 5 Dec 2008, at 13:52, TexasJerky100 at aol.com wrote:

>    Thanks for the response.   This will help me passing the points  
> and compairing the results.
> I however still need to find something that will generate the actual  
> linear equations or similar equations in a
> random fashion.  For instance lets say the program would first  
> generate the actual equations.
>
> y=(2x-1)*4x
> y=2+5(x-1)
> y=(2x+5)+(5x-25)
> y=((x+13)/((x-18))*(2x-1)
>
> Then I could use your program to pass through the values.
>
>
> Frank Hopkins
> Houston, Tx
>
>
>
>
>
>
> In a message dated 12/5/2008 7:29:42 A.M. Central Standard Time, roadierich at googlemail.com 
>  writes:
> When you say linear, I'm assuming fitting y=mx+c, and passing  
> through points?
>
> The line through points (x1, y1) and (x2,y2) is
>
> y - y1 = (y2-y1) / (x2-x1) * (x-x1)
>
> That multiplies out to:
>
> y = (y2-y1)/(x2-x1) * x - (y2-y1)/(x2-x1) + y1
> That gives m = (y2-y1)/(x2-x1) and c =  y1 - (y2-y1)/(x2-x1)
>
> you can then create a class to represent the line:
>
> class Line(object):
>     def __init__(self, (x1,y1), (x2,y2)):
>         "create a line passing through points (x1,y1) and (x2,y2)  
> (inputted as tuples)"
>         self.m = (y2-y1)/(x2-x1)
>         self.c = y1 - self.m
>
>     def is_on_line(self,(x,y)):
>         'Test if point represtented by an (x,y) tuple is on the line"
>         if self. m * x + self.c == y:
>             return True
>         else:
>             return False
>
>     def __str__(self):
>         "returns the equation of the line in the form y=mx+c.  Might  
> be quite long if floats are involved."
>         print "y=%dx + %d" % (self.m, self.c)
>
>
> Then all you have to do is choose a pair of points, then iterate  
> over the list, testing each point in turn, wash, rinse and repeat.
>
> Does that help?
>
> On 4 Dec 2008, at 20:28, TexasJerky100 at aol.com wrote:
>
>>    I am starting out with 7 fixed reference points.  From there I  
>> want  a program that can randomly
>> generate linear equations.  After the equations are generated I  
>> would then like to randomly insert
>> the 7 fixed reference points into the equations and calculate the  
>> results.  I currently have several
>> programs that can generate random string of words from a file that  
>> contains a list of word but is not
>> much help creating random equations.
>>   Do you know if there is such a program that can do what  I am  
>> trying to get accomplished??
>>
>> Thanks
>>
>> Frank Hopkins
>> Houston, Tx
>>
>>
>>
>> Make your life easier with all your friends, email, and favorite  
>> sites in one place. Try it now.
>> _______________________________________________
>> Tutor maillist  -  Tutor at python.org
>> http://mail.python.org/mailman/listinfo/tutor
>
> =
>
>
>
> Make your life easier with all your friends, email, and favorite  
> sites in one place. Try it now.

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From TexasJerky100 at aol.com  Sat Dec  6 17:34:06 2008
From: TexasJerky100 at aol.com (TexasJerky100 at aol.com)
Date: Sat, 6 Dec 2008 11:34:06 EST
Subject: [Tutor] Random equation generator
Message-ID: <d59.3359e87a.366c037e@aol.com>

I think this maybe will work out.  I might have  to just go with the 
generalized form as you suggest
and forget about the random aspect.
 
 
 
 
 
In a message dated 12/6/2008 10:05:16 A.M. Central Standard Time,  
roadierich at googlemail.com writes:

Please  use the reply-all button when responding, so that your message gets 
sent to  the list as well.  


If that's the sort of equation you're after, than the easiest way would  
probably to decide on a generalised form:
 
y=(2x-1)*4x

y = 4*x**2 - 4x

y=2+5(x-1)

y = 5*x - 3

y=(2x+5)+(5x-25)




y = 10*x**2 + 75*x - 125 


y=((x+13)/((x-18))*(2x-1)

y  = (2*x**2 - 19*x -13) / (x - 18)


Except for the last equation, they are all of the "general form" ax^2 +bx  + 
c.


These can be generated using tools from the random module:
(pseudo python)
equation = randint(minimum, maximum) * x ** 2 + randint(minimum,maximum)  * x 
+ randint(minimum,maximum)


if you want to generate equations in the form of the last one you  mentioned, 
it will be a bit more difficult.


You could add a random number of terms with a random power, but actually  
impliementing it might be a bit harder:


import random
def generate_terms(minimum, maximum):
    "generate a list of random terms for an equation of  the form (a*x)**b + 
...  "
    return [(random.randint(minimum, maximum),  random.randint(-1,1)) for x 
in xrange(random.randint(1, 10))]
    
class Line(object):
    epsilon = 1e-15 
    def __init__(self, equation_terms):
        self._equation_terms =  equation_terms
    def is_on_line(self, (x,y)):
        calulated_y = sum((a * x) ** b for a,b  in self._equation_terms)
        return abs(y - calculated_y) <=  self.epsilon #see message from Paul


Then, instead of picking two points, you can do:


line = Line(generate_terms(-25, 25))


then proceed as with my previous message.


getting a nice string representation won't be as easy... unless you're  happy 
with seeing x**-1's dotted around.


You'll need to tweak the values within the generate_terms function to get  
exactly what you want.




Alternatively (and I'm probably going to get shouted at for suggesting  it), 
you could write something that generates random python equations, and use  
some variety of eval() to get a value out of it...  


Does that help?


On 5 Dec 2008, at 13:52, _TexasJerky100 at aol.com_ 
(mailto:TexasJerky100 at aol.com)  wrote:



Thanks for the response.   This will help me  passing the points and 
compairing the results.
I however still need to find something that will generate the actual  linear 
equations or similar equations in a
random fashion.  For instance lets say the program would first  generate the 
actual equations.
 
y=(2x-1)*4x
y=2+5(x-1)
y=(2x+5)+(5x-25)
y=((x+13)/((x-18))*(2x-1)
 
 
Then I could use your program to pass through the values.

 
 
Frank Hopkins
Houston, Tx
 
 
 
 
 
 
 
In a message dated 12/5/2008 7:29:42 A.M. Central Standard Time, 
_roadierich at googlemail.com_ (mailto:roadierich at googlemail.com)   writes:

When  you say linear, I'm assuming fitting y=mx+c, and passing through 
points?  


The line through points (x1, y1) and (x2,y2) is


y - y1 = (y2-y1) / (x2-x1) * (x-x1)


That multiplies out to:


y = (y2-y1)/(x2-x1) * x - (y2-y1)/(x2-x1) + y1
That gives m = (y2-y1)/(x2-x1) and c =  y1 -  (y2-y1)/(x2-x1)


you can then create a class to represent the line:


class Line(object):
    def __init__(self, (x1,y1), (x2,y2)):
        "create a line passing through  points (x1,y1) and (x2,y2) (inputted 
as tuples)"
        self.m = (y2-y1)/(x2-x1)
        self.c = y1 - self.m


def is_on_line(self,(x,y)):
        'Test if point represtented by an  (x,y) tuple is on the line"
        if self. m * x + self.c == y:
            return True
        else:
            return False


def __str__(self):
        "returns the equation of the line in  the form y=mx+c.  Might be 
quite long if floats are involved."
        print "y=%dx + %d" % (self.m,  self.c)




Then all you have to do is choose a pair of points, then iterate over  the 
list, testing each point in turn, wash, rinse and repeat. 


Does that help?
    

 
On 4 Dec 2008, at 20:28, _TexasJerky100 at aol.com_ 
(mailto:TexasJerky100 at aol.com)   wrote:



I am starting out with 7 fixed reference points.   From there I want  a 
program that can randomly
generate linear equations.  After the equations are generated  I would then 
like to randomly insert
the 7 fixed reference points into the equations and calculate the  results.  
I currently have several
programs that can generate random string of words from a file that  contains 
a list of word but is not
much help creating random equations.
  Do you know if there is such a program that can do  what  I am trying to 
get accomplished??
 
Thanks
 
Frank Hopkins
Houston, Tx



 
____________________________________
 Make your life easier with all your friends, email, and favorite sites  in 
one place. _Try  it  now_ 
(http://www.aol.com/?optin=new-dp&icid=aolcom40vanity&ncid=emlcntaolcom00000010) .

_______________________________________________
Tutor  maillist  -  _Tutor at python.org_ (mailto:Tutor at python.org) 
_http://mail.python.org/mailman/listinfo/tutor_ 
(http://mail.python.org/mailman/listinfo/tutor) 





=




 
____________________________________
 Make your life easier with all your friends, email, and favorite sites in  
one place. _Try  it  now_ 
(http://www.aol.com/?optin=new-dp&icid=aolcom40vanity&ncid=emlcntaolcom00000010) .





=

**************Make your life easier with all your friends, email, and 
favorite sites in one place.  Try it now. 
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From newgat11 at yahoo.com  Sat Dec  6 19:01:19 2008
From: newgat11 at yahoo.com (the New me)
Date: Sat, 6 Dec 2008 10:01:19 -0800 (PST)
Subject: [Tutor] Sorting on different fields
Message-ID: <901698.73530.qm@web51009.mail.re2.yahoo.com>



I would like to be able to sort a list of rows, 
each row has (say 4) fields to sort on,

primary key to sort on first, then the second one and so on,

any suggestions and where to look (may be),

Thanks a bunch

Peter


      

From kent37 at tds.net  Sat Dec  6 19:31:59 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sat, 6 Dec 2008 13:31:59 -0500
Subject: [Tutor] Sorting on different fields
In-Reply-To: <901698.73530.qm@web51009.mail.re2.yahoo.com>
References: <901698.73530.qm@web51009.mail.re2.yahoo.com>
Message-ID: <1c2a2c590812061031l1a085c29j78a79820c721c2c8@mail.gmail.com>

On Sat, Dec 6, 2008 at 1:01 PM, the New me <newgat11 at yahoo.com> wrote:
>
>
> I would like to be able to sort a list of rows,
> each row has (say 4) fields to sort on,
>
> primary key to sort on first, then the second one and so on,
>
> any suggestions and where to look (may be),

http://personalpages.tds.net/~kent37/kk/00007.html#e7sorting-on-multiple-keys

Kent

From damontimm at gmail.com  Sun Dec  7 00:08:33 2008
From: damontimm at gmail.com (Damon Timm)
Date: Sat, 6 Dec 2008 18:08:33 -0500
Subject: [Tutor] Newbie Wondering About Threads
Message-ID: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>

Hi Everyone - I am a complete and utter Python newbie (as of today,
honestly) -- am interested in expanding my programming horizons beyond
bash scripting and thought Python would be a nice match for me.

To start, I thought I may try re-writing some of my bash scripts in
Python as a learning tool for me ... and the first one I wanted to
talkle was a script that converts .flac audio files into .mp3 files
... basic idea is I supply a sourceDirectory and targetDirectory and
then recursively convert the source file tree into an identical target
file tree filled with mp3 files.

I'm sure this has been done before (by those much wiser than me) but I
figured I can learn something as I go ... for what I've accomplished
so far, it seems pretty ugly!  But I'm learning ...

Anyhow, I think I got the basics down but I had a thought: can I
thread this program to utilize all of my cores?  And if so, how?

Right now, the lame audio encoder is only hitting one core ... I could
do all this faster if I could pass a variable that says: open 2 or 4
threads instead.

Here is what I've been working on so far -- would appreciate any
insight you may have.

Thanks,
Damon

#!/usr/bin/env python

import os
import sys
import fnmatch
from os import system

fileList = []
rootDir = sys.argv[1]
targetDir = sys.argv[2]

def shell_quote(s):
    """Quote and escape the given string (if necessary) for inclusion in
          a shell command"""
    return "\"%s\"" % s.replace('"', '\\"')

def _mkdir(newdir):
    """works the way a good mkdir should :)
        - already exists, silently complete
        - regular file in the way, raise an exception
        - parent directory(ies) does not exist, make them as well
        http://code.activestate.com/recipes/82465/
    """
    if os.path.isdir(newdir):
        pass
    elif os.path.isfile(newdir):
        raise OSError("a file with the same name as the desired " \
        "dir, '%s', already exists." % newdir)
    else:
        head, tail = os.path.split(newdir)
        if head and not os.path.isdir(head):
            _mkdir(head)
        #print "_mkdir %s" % repr(newdir)
        if tail:
            os.mkdir(newdir)

# get all the flac files and directory structures
for dirpath, subFolders, files in os.walk(rootDir):	
    for file in files:
        if fnmatch.fnmatch(file, '*.flac'):
            flacFileInfo =
[os.path.join(dirpath,file),dirpath+"/",file,dirpath.lstrip(rootDir)+"/"]
            fileList.append(flacFileInfo)

# create new directory structure and mp3 files
for sourceFile,dir,flacfile,strip in fileList:
    mp3File = shell_quote(targetDir + strip + flacfile.strip('.flac') + ".mp3")
    mp3FileDir = targetDir + strip
    sourceFile = shell_quote(sourceFile)

    _mkdir(mp3FileDir)

    flacCommand = "flac --decode --stdout --silent " + sourceFile + "
| lame -V4 --slient - " + mp3File
    system(flacCommand)

From damontimm at gmail.com  Sun Dec  7 03:43:11 2008
From: damontimm at gmail.com (Damon Timm)
Date: Sat, 6 Dec 2008 21:43:11 -0500
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
Message-ID: <262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>

On Sat, Dec 6, 2008 at 6:25 PM, Python Nutter <pythonnutter at gmail.com> wrote:
> I'm on my phone so excuse the simple reply.
> From what I skimmed you are wrapping shell commands which is what I do
> all the time. Some hints. 1) look into popen or subprocess in place of
> execute for more flexibility. I use popen a lot and assigning a popen
> call to an object name let's you parse the output and make informed
> decisions depending on what the shell program outputs.

So I took a peak at subprocess.Popen --> looks like that's the
direction I would be headed for parallel processes ... a real simple
way to see it work for me was:

p2 = subprocess.Popen(["lame","--silent","test.wav","test.mp3"])
p3 = subprocess.Popen(["lame","--silent","test2.wav","test2.mp3"])
p2.wait()
p3.wait()

top showed that both cores get busy and it takes half the time!  So
that's great -- when I tried to add the flac decoding through stdout I
was able to accomplish it as well ... I was mimicing the command of
"flac --decode --stdout test.flac | lame - test.mp3" ... see:

p = subprocess.Popen(["flac","--decode","--stdout","test.flac"],
stdout=subprocess.PIPE)
p2 = subprocess.Popen(["lame","-","test.mp3"], stdin=subprocess.PIPE)
p2.communicate(p.communicate()[0])

That did the trick - it worked!  However, it was *very* slow!  The
python script has a "real" time of 2m22.504s whereas if I run it from
the command line it is only 0m18.594s.  Not sure why this is ...

The last piece of my puzzle though, I am having trouble wrapping my
head around ... I will have a list of files
["file1.flac","file2.flac","file3.flac","etc"] and I want the program
to tackle compressing two at a time ... but not more than two at a
time (or four, or eight, or whatever) because that's not going to help
me at all (I have dual cores right now) ... I am having trouble
thinking how I can create the algorithm that would do this for me ...

Thanks everyone.  Maybe after a good night's sleep it will come to me.
 If you have any ideas - would love to hear them.

Damon

From mwalsh at mwalsh.org  Sun Dec  7 06:33:15 2008
From: mwalsh at mwalsh.org (Martin Walsh)
Date: Sat, 06 Dec 2008 23:33:15 -0600
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
Message-ID: <493B601B.10703@mwalsh.org>

Damon Timm wrote:
> On Sat, Dec 6, 2008 at 6:25 PM, Python Nutter <pythonnutter at gmail.com> wrote:
>> I'm on my phone so excuse the simple reply.
>> From what I skimmed you are wrapping shell commands which is what I do
>> all the time. Some hints. 1) look into popen or subprocess in place of
>> execute for more flexibility. I use popen a lot and assigning a popen
>> call to an object name let's you parse the output and make informed
>> decisions depending on what the shell program outputs.
> 
> So I took a peak at subprocess.Popen --> looks like that's the
> direction I would be headed for parallel processes ... a real simple
> way to see it work for me was:
> 
> p2 = subprocess.Popen(["lame","--silent","test.wav","test.mp3"])
> p3 = subprocess.Popen(["lame","--silent","test2.wav","test2.mp3"])
> p2.wait()
> p3.wait()
> 
> top showed that both cores get busy and it takes half the time!  So
> that's great -- when I tried to add the flac decoding through stdout I
> was able to accomplish it as well ... I was mimicing the command of
> "flac --decode --stdout test.flac | lame - test.mp3" ... see:
> 
> p = subprocess.Popen(["flac","--decode","--stdout","test.flac"],
> stdout=subprocess.PIPE)
> p2 = subprocess.Popen(["lame","-","test.mp3"], stdin=subprocess.PIPE)
> p2.communicate(p.communicate()[0])
> 
> That did the trick - it worked!  However, it was *very* slow!  The
> python script has a "real" time of 2m22.504s whereas if I run it from
> the command line it is only 0m18.594s.  Not sure why this is ...

I'm not certain this completely explains the poor performance, if at
all, but the communicate method of Popen objects will wait until EOF is
reached and the process ends. So IIUC, in your example the process 'p'
runs to completion and only then is its stdout (p.communicate()[0])
passed to stdin of 'p2' by the outer communicate call.

You might try something like this (untested!) ...

p1 = subprocess.Popen(
    ["flac","--decode","--stdout","test.flac"],
    stdout=subprocess.PIPE, stderr=subprocess.PIPE
)
p2 = subprocess.Popen(
    ["lame","-","test.mp3"], stdin=p1.stdout, # <--
    stdout=subprocess.PIPE, stderr=subprocess.PIPE
)
p2.communicate()

... where you directly assign the stdin of 'p2' to be the stdout of 'p1'.

> 
> The last piece of my puzzle though, I am having trouble wrapping my
> head around ... I will have a list of files
> ["file1.flac","file2.flac","file3.flac","etc"] and I want the program
> to tackle compressing two at a time ... but not more than two at a
> time (or four, or eight, or whatever) because that's not going to help
> me at all (I have dual cores right now) ... I am having trouble
> thinking how I can create the algorithm that would do this for me ...

Interesting problem, and not an easy one IMHO, unless you're content
with waiting for a pair of processes to complete before starting two
more. In which case you can just grab two filenames at a time from the
list, define the Popen calls, and wait for (or communicate with) both
before continuing with another pair.

But since you probably want your script to stay busy, and it's
reasonable to assume (I think!) that one of the processes may finish
much sooner or much later than the other... well, it is a bit tricky
(for me, anyway).

Here is my simplistic, not-very-well-thought-out, attempt in
pseudo-code, perhaps it will get you started ...

paths = ["file1.flac","file2.flac", ... "file11.flac"]
procs = []
while paths or procs:
    procs = [p for p in procs if p.poll() is None]
    while paths and len(procs) < 2:
        flac = paths.pop(0)
        procs.append(Popen(['...', flac], ...))
    time.sleep(1)

The idea here is to keep track of running processes in a list, remove
them when they've terminated, and start (append) new processes as
necessary up to the desired max, only while there are files remaining or
processes running.

HTH,
Marty



From newgat11 at yahoo.com  Sun Dec  7 06:47:16 2008
From: newgat11 at yahoo.com (the New me)
Date: Sat, 6 Dec 2008 21:47:16 -0800 (PST)
Subject: [Tutor] Sorting on different fields
In-Reply-To: <1c2a2c590812061031l1a085c29j78a79820c721c2c8@mail.gmail.com>
Message-ID: <323605.57582.qm@web51005.mail.re2.yahoo.com>


Thanks Kent:

Is there an example for sorting on 2 or 3 fields,

I saw this page http://personalpages.tds.net/~kent37/kk/00007.html#e7sorting-on-multiple-keys

It just gives a cursory note:
To sort a list of items with primary and secondary sort keys, provide a key function that returns a tuple of keys. In Python 2.5, both itemgetter() and attrgetter() accept multiple arguments and return functions that create the correct tuples.

that does nt do it for me,
Python is supposed to be programmer user freindly,
is there a straightforward example?

like in SQL one can easily say 
Order by field1 field2 field3

when it comes to sort, books on python give this gimmiky phrase: you can do easily using ...
but no example!!

is one supposed to make a class with attr and item and how are these constructed from the fields being given, and how is the whole row sorted by the field(s) that are part of the row.
the books dont explain that, 
how are the rows sorted, by field1 say, then by field2, etc,
how is one supposed to make the class, so that these things are attributes in the rows.

am sure there must be something on the internet, 
but again it is not satisfactory, 
or the people writing the examples are so smart or everybody else is dum?

Thanks all




--- On Sat, 12/6/08, Kent Johnson <kent37 at tds.net> wrote:

> From: Kent Johnson <kent37 at tds.net>
> Subject: Re: [Tutor] Sorting on different fields
> To: newgat11 at yahoo.com
> Cc: tutor at python.org
> Date: Saturday, December 6, 2008, 1:31 PM
> On Sat, Dec 6, 2008 at 1:01 PM, the New me
> <newgat11 at yahoo.com> wrote:
> >
> >
> > I would like to be able to sort a list of rows,
> > each row has (say 4) fields to sort on,
> >
> > primary key to sort on first, then the second one and
> so on,
> >
> > any suggestions and where to look (may be),
> 
> http://personalpages.tds.net/~kent37/kk/00007.html#e7sorting-on-multiple-keys
> 
> Kent


      

From lie.1296 at gmail.com  Sun Dec  7 08:58:11 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sun, 7 Dec 2008 07:58:11 +0000 (UTC)
Subject: [Tutor] Newbie Wondering About Threads
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
Message-ID: <ghfvmh$8b5$1@ger.gmane.org>

On Sat, 06 Dec 2008 21:43:11 -0500, Damon Timm wrote:

> On Sat, Dec 6, 2008 at 6:25 PM, Python Nutter <pythonnutter at gmail.com>
> wrote:
>> I'm on my phone so excuse the simple reply. From what I skimmed you are
>> wrapping shell commands which is what I do all the time. Some hints. 1)
>> look into popen or subprocess in place of execute for more flexibility.
>> I use popen a lot and assigning a popen call to an object name let's
>> you parse the output and make informed decisions depending on what the
>> shell program outputs.
> 
> So I took a peak at subprocess.Popen --> looks like that's the direction
> I would be headed for parallel processes ... a real simple way to see it
> work for me was:
> 
> p2 = subprocess.Popen(["lame","--silent","test.wav","test.mp3"]) 
> p3 = subprocess.Popen(["lame","--silent","test2.wav","test2.mp3"]) 
> p2.wait()
> p3.wait()

I think when you do that (p2.wait() then p3.wait() ), if p3 finishes 
first, you wouldn't start another p3 until p2 have finished (i.e. until 
p2.wait() returns) and if p2 finishes first, you wouldn't start another 
p2 until p3 finishes (i.e. until p3.wait() returns ).

The solution would be to start and wait() the subprocessess in two 
threads. Use threading module or -- if you use python2.6 -- the new 
multiprocessing module.

Alternatively, you could do a "non-blocking wait", i.e. poll the thread.

while True:
    if p1.poll(): # start another p1
    if p2.poll(): # start another p2

> 
> top showed that both cores get busy and it takes half the time!  So
> that's great -- when I tried to add the flac decoding through stdout I
> was able to accomplish it as well ... I was mimicing the command of
> "flac --decode --stdout test.flac | lame - test.mp3" ... see:
> 
> p = subprocess.Popen(["flac","--decode","--stdout","test.flac"],
> stdout=subprocess.PIPE)
> p2 = subprocess.Popen(["lame","-","test.mp3"], stdin=subprocess.PIPE)
> p2.communicate(p.communicate()[0])
> 
> That did the trick - it worked!  However, it was *very* slow!  The
> python script has a "real" time of 2m22.504s whereas if I run it from
> the command line it is only 0m18.594s.  Not sure why this is ...
> 
> The last piece of my puzzle though, I am having trouble wrapping my head
> around ... I will have a list of files
> ["file1.flac","file2.flac","file3.flac","etc"] and I want the program to
> tackle compressing two at a time ... but not more than two at a time (or
> four, or eight, or whatever) because that's not going to help me at all
> (I have dual cores right now) ... I am having trouble thinking how I can
> create the algorithm that would do this for me ...
> 
> Thanks everyone.  Maybe after a good night's sleep it will come to me.
>  If you have any ideas - would love to hear them.


From lie.1296 at gmail.com  Sun Dec  7 11:31:11 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sun, 7 Dec 2008 10:31:11 +0000 (UTC)
Subject: [Tutor] Sorting on different fields
References: <1c2a2c590812061031l1a085c29j78a79820c721c2c8@mail.gmail.com>
	<323605.57582.qm@web51005.mail.re2.yahoo.com>
Message-ID: <ghg8lf$8b5$2@ger.gmane.org>

On Sat, 06 Dec 2008 21:47:16 -0800, the New me wrote:

> is there a straightforward example?

>>> import operator
>>> k = [[1, 2, 3, 4], [4, 3, 2, 1], [1, 3, 2, 4], [2, 4, 3, 1]]
>>> sorted(l, key=operator.itemgetter(3, 2))
[[4, 3, 2, 1], [2, 4, 3, 1], [1, 3, 2, 4], [1, 2, 3, 4]]
>>> for k in sorted(l, key=operator.itemgetter(0, 2)): print k
... 
[1, 3, 2, 4]
[1, 2, 3, 4]
[2, 4, 3, 1]
[4, 3, 2, 1]
>>> def genkey(item):
...     return item[2]
... 
>>> for k in sorted(l, key=genkey): print k
... 
[4, 3, 2, 1]
[1, 3, 2, 4]
[1, 2, 3, 4]
[2, 4, 3, 1]
>>> def genkey(item):
...     return item[2], item[1]
... 
>>> for k in sorted(l, key=genkey): print k
... 
[4, 3, 2, 1]
[1, 3, 2, 4]
[1, 2, 3, 4]
[2, 4, 3, 1]


From kent37 at tds.net  Sun Dec  7 14:31:43 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 7 Dec 2008 08:31:43 -0500
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
Message-ID: <1c2a2c590812070531u17feef24g1672d86a8738945c@mail.gmail.com>

On Sat, Dec 6, 2008 at 9:43 PM, Damon Timm <damontimm at gmail.com> wrote:


> The last piece of my puzzle though, I am having trouble wrapping my
> head around ... I will have a list of files
> ["file1.flac","file2.flac","file3.flac","etc"] and I want the program
> to tackle compressing two at a time ... but not more than two at a
> time (or four, or eight, or whatever) because that's not going to help
> me at all (I have dual cores right now) ... I am having trouble
> thinking how I can create the algorithm that would do this for me ...

A simple way to do this would be to use poll() instead of wait(). Then
you can check both processes for completion in a loop and start a new
process when one of the current ones ends. You could keep the list of
active processes in a list. Make sure you put a sleep() in the polling
loop, otherwise the loop will consume your CPU!

Another approach is to use a thread pool with one worker for each
process. The thread would call wait() on its child process; when it
finishes the thread will take a new task off the queue. There are
several thread pool recipes in the Python cookbook, for example
http://code.activestate.com/recipes/203871/
http://code.activestate.com/recipes/576576/ (this one has many links
to other pool implementations)

Kent

From damontimm at gmail.com  Sun Dec  7 14:58:52 2008
From: damontimm at gmail.com (Damon Timm)
Date: Sun, 7 Dec 2008 08:58:52 -0500
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <493B601B.10703@mwalsh.org>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
	<493B601B.10703@mwalsh.org>
Message-ID: <262679b50812070558y5c63dc61ra81346bbd122476f@mail.gmail.com>

On Sun, Dec 7, 2008 at 12:33 AM, Martin Walsh <mwalsh at mwalsh.org> wrote:
> I'm not certain this completely explains the poor performance, if at
> all, but the communicate method of Popen objects will wait until EOF is
> reached and the process ends. So IIUC, in your example the process 'p'
> runs to completion and only then is its stdout (p.communicate()[0])
> passed to stdin of 'p2' by the outer communicate call.
>
> You might try something like this (untested!) ...
>
> p1 = subprocess.Popen(
>    ["flac","--decode","--stdout","test.flac"],
>    stdout=subprocess.PIPE, stderr=subprocess.PIPE
> )
> p2 = subprocess.Popen(
>    ["lame","-","test.mp3"], stdin=p1.stdout, # <--
>    stdout=subprocess.PIPE, stderr=subprocess.PIPE
> )
> p2.communicate()

That did the trick!  Got it back down to 20s ... which is what it was
taking on the command line.  Thanks for that!

> Here is my simplistic, not-very-well-thought-out, attempt in
> pseudo-code, perhaps it will get you started ...
>
> paths = ["file1.flac","file2.flac", ... "file11.flac"]
> procs = []
> while paths or procs:
>    procs = [p for p in procs if p.poll() is None]
>    while paths and len(procs) < 2:
>        flac = paths.pop(0)
>        procs.append(Popen(['...', flac], ...))
>    time.sleep(1)

I think I got a little lost with the "procs = [p for p in procs if
p.poll() is None]" statement -- I'm not sure exactly what that is
doing ... but otherwise, I think that makes sense ... will have to try
it out (if not one of the more "robust" thread pool suggestions
(below).

On Sun, Dec 7, 2008 at 2:58 AM, Lie Ryan <lie.1296 at gmail.com> wrote:
> I think when you do that (p2.wait() then p3.wait() ), if p3 finishes
> first, you wouldn't start another p3 until p2 have finished (i.e. until
> p2.wait() returns) and if p2 finishes first, you wouldn't start another
> p2 until p3 finishes (i.e. until p3.wait() returns ).
>
> The solution would be to start and wait() the subprocessess in two
> threads. Use threading module or -- if you use python2.6 -- the new
> multiprocessing module.
>
> Alternatively, you could do a "non-blocking wait", i.e. poll the thread.
>
> while True:
>    if p1.poll(): # start another p1
>    if p2.poll(): # start another p2

Yea, looks like it - I think the trick, for me, will be getting a
dynamic list that can be iterated through ... I experimented a little
with the .poll() function and I think I follow how it is working ...
but really, I am going to have to do a little more "pre-thinking" than
I had to do with the bash version ... not sure if I should create a
class containing the list of flac files or just a number of functions
to handle the list ... whatever way it ends up being, is going to take
a little thought to get it straightened out.  And the objected
oriented part is different than bash -- so, I have to "think
different" too.

On Sun, Dec 7, 2008 at 8:31 AM, Kent Johnson <kent37 at tds.net> wrote:
> A simple way to do this would be to use poll() instead of wait(). Then
> you can check both processes for completion in a loop and start a new
> process when one of the current ones ends. You could keep the list of
> active processes in a list. Make sure you put a sleep() in the polling
> loop, otherwise the loop will consume your CPU!

Thanks for that tip - I already throttled my CPU and had to abort the
first time (without the sleep() function) ... smile.

> Another approach is to use a thread pool with one worker for each
> process. The thread would call wait() on its child process; when it
> finishes the thread will take a new task off the queue. There are
> several thread pool recipes in the Python cookbook, for example
> http://code.activestate.com/recipes/203871/
> http://code.activestate.com/recipes/576576/ (this one has many links
> to other pool implementations)

Oh neat!  I will be honest, more than one screen full of code and I
get a little overwhelmed (at this point) but I am going to check that
idea out.  I was thinking something along these lines, where I can
send all the input/ouput variables along with a number argument
(threads) to a class/function that would then handle everything ... so
using a thread pool may make sense ...

Looks like I would create a loop that went through the list of all the
files to be converted and then sent them all off, one by one, to the
thread pool -- which would then just dish them out so that no more
than 2 (if I chose that) would be converting at a time?  I gotta try
and wrap my head around it ... also, I will be using two subprocesses
to accomplish a single command (one for stdoutput and the other taking
stdinput) as well ... so they have to be packaged together somehow ...
hmm!

Great help everyone.  Not quite as simple as single threading but am
learning quite a bit.  One day, I will figure it out.  Smile.

Damon

From dineshbvadhia at hotmail.com  Sun Dec  7 15:48:27 2008
From: dineshbvadhia at hotmail.com (Dinesh B Vadhia)
Date: Sun, 7 Dec 2008 06:48:27 -0800
Subject: [Tutor] Python on 64-bit ...
Message-ID: <COL103-DS1272DBF22CCE40C6E0851EA3FC0@phx.gbl>

I ask this question in trepidation but does anyone have experience of Python on 64-bit Windows Vista - there I said it!   Feedback on performance and memory usage would be useful to know.  Thanks!

Dinesh
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From kent37 at tds.net  Sun Dec  7 16:47:53 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 7 Dec 2008 10:47:53 -0500
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <262679b50812070558y5c63dc61ra81346bbd122476f@mail.gmail.com>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
	<493B601B.10703@mwalsh.org>
	<262679b50812070558y5c63dc61ra81346bbd122476f@mail.gmail.com>
Message-ID: <1c2a2c590812070747w36ae6da9i4f8ba9343af43a62@mail.gmail.com>

On Sun, Dec 7, 2008 at 8:58 AM, Damon Timm <damontimm at gmail.com> wrote:
> On Sun, Dec 7, 2008 at 12:33 AM, Martin Walsh <mwalsh at mwalsh.org> wrote:

>> Here is my simplistic, not-very-well-thought-out, attempt in
>> pseudo-code, perhaps it will get you started ...
>>
>> paths = ["file1.flac","file2.flac", ... "file11.flac"]
>> procs = []
>> while paths or procs:
>>    procs = [p for p in procs if p.poll() is None]
>>    while paths and len(procs) < 2:
>>        flac = paths.pop(0)
>>        procs.append(Popen(['...', flac], ...))
>>    time.sleep(1)
>
> I think I got a little lost with the "procs = [p for p in procs if
> p.poll() is None]" statement

It's called a list comprehension
http://personalpages.tds.net/~kent37/kk/00003.html

Essentially it creates a new list from all the elements it the old
list that are still running.

> On Sun, Dec 7, 2008 at 2:58 AM, Lie Ryan <lie.1296 at gmail.com> wrote:

> Yea, looks like it - I think the trick, for me, will be getting a
> dynamic list that can be iterated through ... I experimented a little
> with the .poll() function and I think I follow how it is working ...
> but really, I am going to have to do a little more "pre-thinking" than
> I had to do with the bash version ... not sure if I should create a
> class containing the list of flac files or just a number of functions
> to handle the list ... whatever way it ends up being, is going to take
> a little thought to get it straightened out.  And the objected
> oriented part is different than bash -- so, I have to "think
> different" too.

I don't think you need any classes for this. A simple list of file
names should be fine. A function that takes a file name as a
parameter, starts a process to process the file, and returns the
resulting Popen object would also be helpful.

> On Sun, Dec 7, 2008 at 8:31 AM, Kent Johnson <kent37 at tds.net> wrote:

> Oh neat!  I will be honest, more than one screen full of code and I
> get a little overwhelmed (at this point) but I am going to check that
> idea out.  I was thinking something along these lines, where I can
> send all the input/ouput variables along with a number argument
> (threads) to a class/function that would then handle everything ... so
> using a thread pool may make sense ...
>
> Looks like I would create a loop that went through the list of all the
> files to be converted and then sent them all off, one by one, to the
> thread pool -- which would then just dish them out so that no more
> than 2 (if I chose that) would be converting at a time?

Yes, that's right.

>  I gotta try
> and wrap my head around it ... also, I will be using two subprocesses
> to accomplish a single command (one for stdoutput and the other taking
> stdinput) as well ... so they have to be packaged together somehow ...

A function as mentioned above would help. For the threaded solution
the function could just start the child process and wait for it to
finish, it doesn't have to return anything. Each thread will block on
its associated child.

Kent

From lie.1296 at gmail.com  Sun Dec  7 18:14:14 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sun, 7 Dec 2008 17:14:14 +0000 (UTC)
Subject: [Tutor] 'for' loops
References: <493484D2.50603@socal.rr.com> <gh22bl$rno$1@ger.gmane.org>
Message-ID: <ghh096$jg4$1@ger.gmane.org>

On Tue, 02 Dec 2008 01:17:41 +0000, Alan Gauld wrote:

> while loops are used much less in Python than in other languages because
> for loops are so powerful.

Actually, I think python's for-loop is so powerful that while loop could 
be removed from the language and no power would be lost (although many 
idioms are much better (and faster) written in while loop). This is 
because python allows infinite-length iterable, you can emulate "while 
True" loop with something like this:

eternity = __import__('itertools').count()
for ever in eternity:
    print "can't stoooop...."

# the code above is slightly obfuscated, 
# I wouldn't normally write it like that
# ...
# [1]

> while lops are generally used in cases where you don't know how many
> times you need to loop or you want to loop 'forever'.
> 
> while True:
>     print 'Can't stop me now!'
> 
> will keep on looping until you close the program
> 
> c = 0
> while c != -1:
>     c = int(raw_input('Enter a number(-1 to stop) ')) 
>     print c
> 
> will keep looping until the user enters -1

while that can be turned into something like this:

for ever in eternity:
    c = int(raw_input('Enter a number(-1 to stop) ')) 
    print c

OR

from itertools import repeat
from functools import partial
def ask():
    def stop(): raise StopIteration
    asker = partial(raw_input, 'Enter a number(-1 to stop) ')
    for n in repeat(asker):
        n = n()
        yield n if n != '-1' else stop()

for c in ask():
    print c

> More info and a comparison with JabaScript and VBScript can be found in
> my tutor in the looping topic.

[1] I cheated slightly, there is a while loop in the C code for itertools
[2] I'm not suggesting that while loop should go away, I'm illustrating 
the power of the for(ce).


From lie.1296 at gmail.com  Sun Dec  7 18:25:50 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sun, 7 Dec 2008 17:25:50 +0000 (UTC)
Subject: [Tutor] try except block for multiple statements
References: <fbf64d2b0812011744s503e2473g71b46f65d09dcd8a@mail.gmail.com>
Message-ID: <ghh0uu$jg4$2@ger.gmane.org>

On Mon, 01 Dec 2008 20:44:20 -0500, Bryan Fodness wrote:

> I would like to use a try except to see if a value exists.  But, when I
> use the following, if a does not exist it exits.  I understand why this
> does this, but is there a way to get b,c, and d if a does not exist
> without using a try except for every statement?
> 
> try:
>     fo.write("a = %s\n" %plan.a)
>     fo.write("b = %s\n" %plan.b)
>     fo.write("c = %s\n" %plan.c)
>     fo.write("d = %s\n" %plan.d)
> except AttributeError:
>     pass

Or:
texts = ["a = %s\n" % plan.a, 
         "b = %s\n" % plan.b, 
         "c = %s\n" % plan.c, 
         "d = %s\n" % plan.d
        ]

for text in texts:
    try:
        fo.write(text)
    except AttributeError:
        pass


From newgat11 at yahoo.com  Sun Dec  7 18:58:17 2008
From: newgat11 at yahoo.com (the New me)
Date: Sun, 7 Dec 2008 09:58:17 -0800 (PST)
Subject: [Tutor] Tutor Digest, Vol 58, Issue 22
Message-ID: <714025.14863.qm@web51006.mail.re2.yahoo.com>


That worked,

I tried it with string elements also

Thanks a bunch



--- On Sun, 12/7/08, tutor-request at python.org <tutor-request at python.org> wrote:

> From: tutor-request at python.org <tutor-request at python.org>
> Subject: Tutor Digest, Vol 58, Issue 22
> To: tutor at python.org
> Date: Sunday, December 7, 2008, 6:00 AM
> Send Tutor mailing list submissions to
> 	tutor at python.org
> 
> To subscribe or unsubscribe via the World Wide Web, visit
> 	http://mail.python.org/mailman/listinfo/tutor
> or, via email, send a message with subject or body
> 'help' to
> 	tutor-request at python.org
> 
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> 	tutor-owner at python.org
> 
> When replying, please edit your Subject line so it is more
> specific
> than "Re: Contents of Tutor digest..."
> 
> 
> Today's Topics:
> 
>    1. Re: Newbie Wondering About Threads (Lie Ryan)
>    2. Re: Sorting on different fields (Lie Ryan)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Sun, 7 Dec 2008 07:58:11 +0000 (UTC)
> From: Lie Ryan <lie.1296 at gmail.com>
> Subject: Re: [Tutor] Newbie Wondering About Threads
> To: tutor at python.org
> Message-ID: <ghfvmh$8b5$1 at ger.gmane.org>
> Content-Type: text/plain; charset=UTF-8
> 
> On Sat, 06 Dec 2008 21:43:11 -0500, Damon Timm wrote:
> 
> > On Sat, Dec 6, 2008 at 6:25 PM, Python Nutter
> <pythonnutter at gmail.com>
> > wrote:
> >> I'm on my phone so excuse the simple reply.
> From what I skimmed you are
> >> wrapping shell commands which is what I do all the
> time. Some hints. 1)
> >> look into popen or subprocess in place of execute
> for more flexibility.
> >> I use popen a lot and assigning a popen call to an
> object name let's
> >> you parse the output and make informed decisions
> depending on what the
> >> shell program outputs.
> > 
> > So I took a peak at subprocess.Popen --> looks like
> that's the direction
> > I would be headed for parallel processes ... a real
> simple way to see it
> > work for me was:
> > 
> > p2 =
> subprocess.Popen(["lame","--silent","test.wav","test.mp3"])
> 
> > p3 =
> subprocess.Popen(["lame","--silent","test2.wav","test2.mp3"])
> 
> > p2.wait()
> > p3.wait()
> 
> I think when you do that (p2.wait() then p3.wait() ), if p3
> finishes 
> first, you wouldn't start another p3 until p2 have
> finished (i.e. until 
> p2.wait() returns) and if p2 finishes first, you
> wouldn't start another 
> p2 until p3 finishes (i.e. until p3.wait() returns ).
> 
> The solution would be to start and wait() the subprocessess
> in two 
> threads. Use threading module or -- if you use python2.6 --
> the new 
> multiprocessing module.
> 
> Alternatively, you could do a "non-blocking
> wait", i.e. poll the thread.
> 
> while True:
>     if p1.poll(): # start another p1
>     if p2.poll(): # start another p2
> 
> > 
> > top showed that both cores get busy and it takes half
> the time!  So
> > that's great -- when I tried to add the flac
> decoding through stdout I
> > was able to accomplish it as well ... I was mimicing
> the command of
> > "flac --decode --stdout test.flac | lame -
> test.mp3" ... see:
> > 
> > p =
> subprocess.Popen(["flac","--decode","--stdout","test.flac"],
> > stdout=subprocess.PIPE)
> > p2 =
> subprocess.Popen(["lame","-","test.mp3"],
> stdin=subprocess.PIPE)
> > p2.communicate(p.communicate()[0])
> > 
> > That did the trick - it worked!  However, it was
> *very* slow!  The
> > python script has a "real" time of 2m22.504s
> whereas if I run it from
> > the command line it is only 0m18.594s.  Not sure why
> this is ...
> > 
> > The last piece of my puzzle though, I am having
> trouble wrapping my head
> > around ... I will have a list of files
> >
> ["file1.flac","file2.flac","file3.flac","etc"]
> and I want the program to
> > tackle compressing two at a time ... but not more than
> two at a time (or
> > four, or eight, or whatever) because that's not
> going to help me at all
> > (I have dual cores right now) ... I am having trouble
> thinking how I can
> > create the algorithm that would do this for me ...
> > 
> > Thanks everyone.  Maybe after a good night's sleep
> it will come to me.
> >  If you have any ideas - would love to hear them.
> 
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Sun, 7 Dec 2008 10:31:11 +0000 (UTC)
> From: Lie Ryan <lie.1296 at gmail.com>
> Subject: Re: [Tutor] Sorting on different fields
> To: tutor at python.org
> Message-ID: <ghg8lf$8b5$2 at ger.gmane.org>
> Content-Type: text/plain; charset=UTF-8
> 
> On Sat, 06 Dec 2008 21:47:16 -0800, the New me wrote:
> 
> > is there a straightforward example?
> 
> >>> import operator
> >>> k = [[1, 2, 3, 4], [4, 3, 2, 1], [1, 3, 2, 4],
> [2, 4, 3, 1]]
> >>> sorted(l, key=operator.itemgetter(3, 2))
> [[4, 3, 2, 1], [2, 4, 3, 1], [1, 3, 2, 4], [1, 2, 3, 4]]
> >>> for k in sorted(l, key=operator.itemgetter(0,
> 2)): print k
> ... 
> [1, 3, 2, 4]
> [1, 2, 3, 4]
> [2, 4, 3, 1]
> [4, 3, 2, 1]
> >>> def genkey(item):
> ...     return item[2]
> ... 
> >>> for k in sorted(l, key=genkey): print k
> ... 
> [4, 3, 2, 1]
> [1, 3, 2, 4]
> [1, 2, 3, 4]
> [2, 4, 3, 1]
> >>> def genkey(item):
> ...     return item[2], item[1]
> ... 
> >>> for k in sorted(l, key=genkey): print k
> ... 
> [4, 3, 2, 1]
> [1, 3, 2, 4]
> [1, 2, 3, 4]
> [2, 4, 3, 1]
> 
> 
> 
> ------------------------------
> 
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
> 
> 
> End of Tutor Digest, Vol 58, Issue 22
> *************************************



      

From robert.johansson at math.umu.se  Sun Dec  7 18:34:18 2008
From: robert.johansson at math.umu.se (Robert Johansson)
Date: Sun, 7 Dec 2008 18:34:18 +0100
Subject: [Tutor] Psyco module
Message-ID: <000901c95892$08655d20$19301760$@johansson@math.umu.se>

Dear all, I'm trying to get my Python stuff to work on my new computer but I
have problems getting the Psyco module installed. First I tried Python 2.6
(which worked fine) but discovered that Psyco wasn't prepared for it. I
uninstalled Python 2.6 and when for 2.5.2 instead, but the problem with
installing Psyco remains. Anyone how knows what to do?

 

/Robert

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From kent37 at tds.net  Sun Dec  7 20:45:12 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 7 Dec 2008 14:45:12 -0500
Subject: [Tutor] try except block for multiple statements
In-Reply-To: <ghh0uu$jg4$2@ger.gmane.org>
References: <fbf64d2b0812011744s503e2473g71b46f65d09dcd8a@mail.gmail.com>
	<ghh0uu$jg4$2@ger.gmane.org>
Message-ID: <1c2a2c590812071145m48160d1chfea4eac186954d46@mail.gmail.com>

On Sun, Dec 7, 2008 at 12:25 PM, Lie Ryan <lie.1296 at gmail.com> wrote:

> texts = ["a = %s\n" % plan.a,
>         "b = %s\n" % plan.b,
>         "c = %s\n" % plan.c,
>         "d = %s\n" % plan.d
>        ]
>
> for text in texts:
>    try:
>        fo.write(text)
>    except AttributeError:
>        pass

No, the AttributeError will come during the creation of texts, not in the loop.

Kent

From kent37 at tds.net  Sun Dec  7 20:45:55 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 7 Dec 2008 14:45:55 -0500
Subject: [Tutor] Psyco module
In-Reply-To: <6717622033615662971@unknownmsgid>
References: <6717622033615662971@unknownmsgid>
Message-ID: <1c2a2c590812071145y4d2b3e77hdb09baa2182df828@mail.gmail.com>

On Sun, Dec 7, 2008 at 12:34 PM, Robert Johansson
<robert.johansson at math.umu.se> wrote:
> Dear all, I'm trying to get my Python stuff to work on my new computer but I
> have problems getting the Psyco module installed. First I tried Python 2.6
> (which worked fine) but discovered that Psyco wasn't prepared for it. I
> uninstalled Python 2.6 and when for 2.5.2 instead, but the problem with
> installing Psyco remains. Anyone how knows what to do?

What OS? What problem do you have?

Kent

From damontimm at gmail.com  Sun Dec  7 21:10:46 2008
From: damontimm at gmail.com (Damon Timm)
Date: Sun, 7 Dec 2008 15:10:46 -0500
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <1c2a2c590812070747w36ae6da9i4f8ba9343af43a62@mail.gmail.com>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
	<493B601B.10703@mwalsh.org>
	<262679b50812070558y5c63dc61ra81346bbd122476f@mail.gmail.com>
	<1c2a2c590812070747w36ae6da9i4f8ba9343af43a62@mail.gmail.com>
Message-ID: <262679b50812071210s651f35c4hac9e6a5f7dd98e11@mail.gmail.com>

On Sun, Dec 7, 2008 at 10:47 AM, Kent Johnson <kent37 at tds.net> wrote:
> A function as mentioned above would help. For the threaded solution
> the function could just start the child process and wait for it to
> finish, it doesn't have to return anything. Each thread will block on
> its associated child.

I think I did it!  Woo hoo!  (cheers all around! drinks on me!)

First, I found that using the Popen.communicate() function wasn't
going to work (because it sits there and waits for until it's done
before continuing); so, I ditched that, created my own little function
that returned the Popen object and went from there ... I mixed in one
super-long audio file file with all the others it seems to work
without a hitch (so far) ... watching top I see both processors
running at max during the lame processing.

Check it out (there are probably sexier ways to populate the *.mp3
files but I was more interested in the threads):
---
import time
import subprocess

totProcs = 2 #number of processes to spawn before waiting
flacFiles = [["test.flac","test.mp3"],["test2.flac","test2.mp3"],\
        ["test3.flac","test3.mp3"],["test4.flac","test4.mp3"],\
        ["test5.flac","test5.mp3"],["test6.flac","test6.mp3"]]
procs = []

def flac_to_mp3(flacfile,mp3file):
    print "beginning to process " + flacfile
    p = subprocess.Popen(["flac","--decode","--stdout","--silent",flacfile],
stdout=subprocess.PIPE)
    p1 = subprocess.Popen(["lame","--silent","-",mp3file], stdin=p.stdout)
    return p1

while flacFiles or procs:
    procs = [p for p in procs if p.poll() is None]
    while flacFiles and len(procs) < totProcs:
        file = flacFiles.pop(0)
        procs.append(flac_to_mp3(file[0],file[1]))
    time.sleep(1)
------[EOF]------

Thanks again - onward I go!

Damon

From chudxx at gmail.com  Sun Dec  7 22:14:14 2008
From: chudxx at gmail.com (R. Santos)
Date: Sun, 7 Dec 2008 13:14:14 -0800
Subject: [Tutor] selecting attributes of all elements in numpy arrays
Message-ID: <41c7a4a50812071314vdad7143wd64892a76dcd894d@mail.gmail.com>

I have a numpy recarray (rd) with a datetime  field (bar_dt) and I
want to filter the recarray by year.  So far, the only way I've been
able to do this is by using
rd[np.array([i.year for i in rd.bar_dt])==2008].

Is there a better way to do this?  It seems like I must be overlooking
something.

Thanks for any help.

From kent37 at tds.net  Mon Dec  8 03:35:34 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 7 Dec 2008 21:35:34 -0500
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <262679b50812071210s651f35c4hac9e6a5f7dd98e11@mail.gmail.com>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
	<493B601B.10703@mwalsh.org>
	<262679b50812070558y5c63dc61ra81346bbd122476f@mail.gmail.com>
	<1c2a2c590812070747w36ae6da9i4f8ba9343af43a62@mail.gmail.com>
	<262679b50812071210s651f35c4hac9e6a5f7dd98e11@mail.gmail.com>
Message-ID: <1c2a2c590812071835j1dac192cm5c88df65397fed01@mail.gmail.com>

On Sun, Dec 7, 2008 at 3:10 PM, Damon Timm <damontimm at gmail.com> wrote:

> I think I did it!  Woo hoo!  (cheers all around! drinks on me!)

Cool! Where are we meeting for drinks? ;-)

> flacFiles = [["test.flac","test.mp3"],["test2.flac","test2.mp3"],\
>        ["test3.flac","test3.mp3"],["test4.flac","test4.mp3"],\
>        ["test5.flac","test5.mp3"],["test6.flac","test6.mp3"]]

There is no need to include both the flac file name and the mp3 file
name if the roots match. You can use os.path functions to split the
extension or the quick-and-dirty way:
  mp3file = flacfile.rsplit('.', 1)[0] + '.mp3'

Kent

From damontimm at gmail.com  Mon Dec  8 03:46:00 2008
From: damontimm at gmail.com (Damon Timm)
Date: Sun, 7 Dec 2008 21:46:00 -0500
Subject: [Tutor] Newbie Wondering About Threads
In-Reply-To: <1c2a2c590812071835j1dac192cm5c88df65397fed01@mail.gmail.com>
References: <262679b50812061508p50306f2dg51d5aa2c5421c293@mail.gmail.com>
	<af90b3410812061525t1df83164yc4e9057012f41f66@mail.gmail.com>
	<262679b50812061843oe8ebf9fkc964e2ac5f986d3e@mail.gmail.com>
	<493B601B.10703@mwalsh.org>
	<262679b50812070558y5c63dc61ra81346bbd122476f@mail.gmail.com>
	<1c2a2c590812070747w36ae6da9i4f8ba9343af43a62@mail.gmail.com>
	<262679b50812071210s651f35c4hac9e6a5f7dd98e11@mail.gmail.com>
	<1c2a2c590812071835j1dac192cm5c88df65397fed01@mail.gmail.com>
Message-ID: <262679b50812071846y52e6eadel4726f49c14a9af62@mail.gmail.com>

On Sun, Dec 7, 2008 at 9:35 PM, Kent Johnson <kent37 at tds.net> wrote:
> There is no need to include both the flac file name and the mp3 file
> name if the roots match. You can use os.path functions to split the
> extension or the quick-and-dirty way:
>  mp3file = flacfile.rsplit('.', 1)[0] + '.mp3'

That is *so* what I was looking for!

You guys are awesome.

Damon

>
> Kent
>

From pythonnutter at gmail.com  Mon Dec  8 12:49:07 2008
From: pythonnutter at gmail.com (Python Nutter)
Date: Mon, 8 Dec 2008 22:49:07 +1100
Subject: [Tutor] Psyco module
In-Reply-To: <1c2a2c590812071145y4d2b3e77hdb09baa2182df828@mail.gmail.com>
References: <6717622033615662971@unknownmsgid>
	<1c2a2c590812071145y4d2b3e77hdb09baa2182df828@mail.gmail.com>
Message-ID: <af90b3410812080349p731ccd69i8a470d410ca93519@mail.gmail.com>

It only runs on Intel 386-compatible processors. Once we know what CPU
you are using then we can figure it out better.

From lawrence.wickline at gmail.com  Mon Dec  8 17:55:40 2008
From: lawrence.wickline at gmail.com (Lawrence Wickline)
Date: Mon, 8 Dec 2008 08:55:40 -0800
Subject: [Tutor] Sorting a dictionary on a value in a list.
In-Reply-To: <ghddr6$15v$1@ger.gmane.org>
References: <8191FB37-C507-446C-933F-246C5073689D@gmail.com>
	<f90615120812031658g6b49d229y1b60cefc3d9f89b4@mail.gmail.com>
	<1c2a2c590812031742m57ed6f0av1b34fa8f6331a548@mail.gmail.com>
	<045316B5-CB8D-4C92-9CA4-E23FC5B3B08D@gmail.com>
	<ghddr6$15v$1@ger.gmane.org>
Message-ID: <9A73889B-3727-4289-BDDE-43642B5267EB@gmail.com>


On Dec 6, 2008, at 12:41 AM, Lie Ryan wrote:
>
> In most cases, in processing involving networking, the bottleneck is  
> the
> network speed itself. To speed things up by optimizing your own code
> might not make your download significantly faster (getting 60 seconds
> faster is great for scripts that usually runs for 70 seconds, but is a
> waste of development time for scripts that usually run for 1 hour)
>
> Usually a multi-threading downloader might be a better chance to
> improvement, especially for 1)  downloading from different site, 2)  
> the
> remote sites have speed limit, 3) you have faster download link than  
> the
> server can gives


In this particular case everything is on the local network. This is  
actually part of a hadoop map/reduce system I am learning, so reducing  
cpu is of high value. if network pull times become and issue the  
cluster can be expanded and the time between pulls can be  reduced. As  
of this morning I am being directed to make the reducer usable both in  
the mapper and then again as a reducer.  This has forced me to rework  
everything to work so that it can be called as a module.

I have never learned java so that wasn't' an option and the more I am  
working with it python seems to be the perfect fit for hadoop type  
work. Really fun stuff.


From sander.sweers at gmail.com  Mon Dec  8 18:15:36 2008
From: sander.sweers at gmail.com (Sander Sweers)
Date: Mon, 8 Dec 2008 18:15:36 +0100
Subject: [Tutor] File IO flush
Message-ID: <b65fbb130812080915na9f4e95je960cb80d6f11ff4@mail.gmail.com>

Hello All, I was playing around with the zipfile module and wrote a
simple script to unzip a zip file. I then looked around on the
internet and found the recipe 252508 [1] on the active state cookbook
website.

In this recipe the author calls flush() and then close() on a file
object being written to disk. Now I understand what flush does but
would close() also flush the buffers to disk?

Thanks
Sander

[1] http://code.activestate.com/recipes/252508/

From kent37 at tds.net  Mon Dec  8 18:55:55 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 8 Dec 2008 12:55:55 -0500
Subject: [Tutor] File IO flush
In-Reply-To: <b65fbb130812080915na9f4e95je960cb80d6f11ff4@mail.gmail.com>
References: <b65fbb130812080915na9f4e95je960cb80d6f11ff4@mail.gmail.com>
Message-ID: <1c2a2c590812080955p309b992eide1f26d4940b291f@mail.gmail.com>

On Mon, Dec 8, 2008 at 12:15 PM, Sander Sweers <sander.sweers at gmail.com> wrote:
> Hello All, I was playing around with the zipfile module and wrote a
> simple script to unzip a zip file. I then looked around on the
> internet and found the recipe 252508 [1] on the active state cookbook
> website.
>
> In this recipe the author calls flush() and then close() on a file
> object being written to disk. Now I understand what flush does but
> would close() also flush the buffers to disk?

Yes, close() will flush first; AFAIK there is no reason to call
flush() immediately before close() on the same file object.

Kent

From jay at splitstreams.com  Mon Dec  8 19:01:00 2008
From: jay at splitstreams.com (Jay Deiman)
Date: Mon, 08 Dec 2008 12:01:00 -0600
Subject: [Tutor] rrdtool examples.
In-Reply-To: <1228440339.19777.21.camel@M13425>
References: <1228440339.19777.21.camel@M13425>
Message-ID: <493D60DC.5020802@splitstreams.com>

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Jeremiah Jester wrote:
> Is anyone on here using the python-rrdtool module for graphing and
> analysis? If so, do you have some sample scripts you could show me.
> There doesn't seem to be a lot out there as far as real world python
> examples.
> 
> Thanks,
> JJ

Actually, I was just playing around with the rrdtool library for python
last week.  It turns out that you basically just use the command line
options as options for the different method calls (like create()).  All
you really have to do is check out the man pages for rrdtool to have all
the documentation you need for the rrdtool python module.  You literally
pass in the command line opts just as they would appear on the command
line.  Here is a quick little script that I whipped up for playing purposes:
- ------------------------

#!/usr/bin/env python

import rrdtool , time , random

stime = int(time.time()) - 5 * 86400
dpoints = 1000
etime = stime + (dpoints * 300)
fname = 'test.rrd'
gfname = 'test.png'

rrdtool.create('test.rrd' ,
        '--start' , str(stime) ,
        'DS:speed:COUNTER:600:U:U' ,
        'RRA:AVERAGE:0.5:1:576' ,
        'RRA:AVERAGE:0.5:6:336'
)

ctime = stime
cmiles = 0
for i in xrange(dpoints):
    bump = random.randint(1 , 20)
    cmiles += bump
    ctime += 300
    rrdtool.update(fname , '%d:%d' % (ctime , cmiles))

rrdtool.graph(gfname ,
        '--start' , str(etime - (24 * 3600)) ,
        '--end' , str(etime) ,
        '--vertical-label' , 'Speed m/h' ,
        '--imgformat' , 'PNG' ,
        '--title' , 'Speeds' ,
        '--lower-limit' , '0' ,
        'DEF:myspeed=%s:speed:AVERAGE' % fname ,
        'CDEF:mph=myspeed,3600,*' ,
        'VDEF:msmax=mph,MAXIMUM' ,
        'VDEF:msavg=mph,AVERAGE' ,
        'VDEF:msmin=mph,MINIMUM' ,
        'VDEF:mspct=mph,95,PERCENT' ,
        'LINE1:mph#FF0000:My Speed' ,
        r'GPRINT:msmax:Max\: %6.1lf mph' ,
        r'GPRINT:msavg:Avg\: %6.1lf mph' ,
        r'GPRINT:msmin:Min\: %6.1lf mph\l' ,
        r'GPRINT:mspct:95th Perc\: %6.1lf mph\l'
)

- ------------------------

That, coupled with the rrdtool man pages (which are very good, complete
with examples) should be enough to get you started.

- --
Jay Deiman

\033:wq!
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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=h7CZ
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From jeremiah.jester at panasonic.aero  Mon Dec  8 20:11:11 2008
From: jeremiah.jester at panasonic.aero (Jeremiah Jester)
Date: Mon, 08 Dec 2008 11:11:11 -0800
Subject: [Tutor] rrdtool examples.
In-Reply-To: <493D60DC.5020802@splitstreams.com>
References: <1228440339.19777.21.camel@M13425>
	<493D60DC.5020802@splitstreams.com>
Message-ID: <1228763471.9472.18.camel@M13425>

Thanks Jay. This helps!

JJ

On Mon, 2008-12-08 at 10:01 -0800, Jay Deiman wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Jeremiah Jester wrote:
> > Is anyone on here using the python-rrdtool module for graphing and
> > analysis? If so, do you have some sample scripts you could show me.
> > There doesn't seem to be a lot out there as far as real world python
> > examples.
> >
> > Thanks,
> > JJ
> 
> Actually, I was just playing around with the rrdtool library for
> python
> last week.  It turns out that you basically just use the command line
> options as options for the different method calls (like create()).
> All
> you really have to do is check out the man pages for rrdtool to have
> all
> the documentation you need for the rrdtool python module.  You
> literally
> pass in the command line opts just as they would appear on the command
> line.  Here is a quick little script that I whipped up for playing
> purposes:
> - ------------------------
> 
> #!/usr/bin/env python
> 
> import rrdtool , time , random
> 
> stime = int(time.time()) - 5 * 86400
> dpoints = 1000
> etime = stime + (dpoints * 300)
> fname = 'test.rrd'
> gfname = 'test.png'
> 
> rrdtool.create('test.rrd' ,
>         '--start' , str(stime) ,
>         'DS:speed:COUNTER:600:U:U' ,
>         'RRA:AVERAGE:0.5:1:576' ,
>         'RRA:AVERAGE:0.5:6:336'
> )
> 
> ctime = stime
> cmiles = 0
> for i in xrange(dpoints):
>     bump = random.randint(1 , 20)
>     cmiles += bump
>     ctime += 300
>     rrdtool.update(fname , '%d:%d' % (ctime , cmiles))
> 
> rrdtool.graph(gfname ,
>         '--start' , str(etime - (24 * 3600)) ,
>         '--end' , str(etime) ,
>         '--vertical-label' , 'Speed m/h' ,
>         '--imgformat' , 'PNG' ,
>         '--title' , 'Speeds' ,
>         '--lower-limit' , '0' ,
>         'DEF:myspeed=%s:speed:AVERAGE' % fname ,
>         'CDEF:mph=myspeed,3600,*' ,
>         'VDEF:msmax=mph,MAXIMUM' ,
>         'VDEF:msavg=mph,AVERAGE' ,
>         'VDEF:msmin=mph,MINIMUM' ,
>         'VDEF:mspct=mph,95,PERCENT' ,
>         'LINE1:mph#FF0000:My Speed' ,
>         r'GPRINT:msmax:Max\: %6.1lf mph' ,
>         r'GPRINT:msavg:Avg\: %6.1lf mph' ,
>         r'GPRINT:msmin:Min\: %6.1lf mph\l' ,
>         r'GPRINT:mspct:95th Perc\: %6.1lf mph\l'
> )
> 
> - ------------------------
> 
> That, coupled with the rrdtool man pages (which are very good,
> complete
> with examples) should be enough to get you started.
> 
> - --
> Jay Deiman
> 
> \033:wq!
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v2.0.9 (GNU/Linux)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
> 
> iEYEARECAAYFAkk9YNwACgkQQ0lr+ZVKSBiWTQCgoBuzQVeRHBlrJ7GONQAL0RFT
> qOwAn3cnbZot0q1qGf6mOFHS8QgQc53o
> =h7CZ
> -----END PGP SIGNATURE-----
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
> 
> 
> 



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From damontimm at gmail.com  Tue Dec  9 01:05:36 2008
From: damontimm at gmail.com (Damon Timm)
Date: Mon, 8 Dec 2008 19:05:36 -0500
Subject: [Tutor] list.index() question
Message-ID: <262679b50812081605s1888bf06vcbca2de976f89013@mail.gmail.com>

Hi again!

(Now that everyone was so helpful the first time you'll never get rid of me!)

I had a question about using the index() function on a list -- as I
walk the directory path, I want to see if a directory contains any
files ending in a certain type ... if it does, I wanna do some stuff
... if not, I would like to move on ... .

for dirpath, subFolders, files in os.walk(rootDir):
     try:
         i = files.index("*.flac") #how do I make it search for files
that end in ".flac" ?
         for file in files:
                #do some things in here to sort my files
     except ValueError:
         pass

Basically: how do I make it match *.flac ?  I couldn't find anything
on google (searching for "python index" just gets me a lot of indexes
of python docs - wink)

Thanks again,

Damon

From john at fouhy.net  Tue Dec  9 01:29:54 2008
From: john at fouhy.net (John Fouhy)
Date: Tue, 9 Dec 2008 13:29:54 +1300
Subject: [Tutor] list.index() question
In-Reply-To: <262679b50812081605s1888bf06vcbca2de976f89013@mail.gmail.com>
References: <262679b50812081605s1888bf06vcbca2de976f89013@mail.gmail.com>
Message-ID: <5e58f2e40812081629m1927e787u53c252e760533974@mail.gmail.com>

On 09/12/2008, Damon Timm <damontimm at gmail.com> wrote:
>  Basically: how do I make it match *.flac ?  I couldn't find anything
>  on google (searching for "python index" just gets me a lot of indexes
>  of python docs - wink)

Hi Damon,

The fnmatch module will help here.  It basically implements unix-style
filename patterns.  For example:

import os
import fnmatch

files = os.listdir('.')
flac_files = fnmatch(files, '*.flac')

So, to test whether you have any flac files, you can just test whether
fnmatch(files, '*.flac') is empty.

If you wanted to roll your own solution (the fnmatch module is a bit
obscure, I think), you could do something with os.path.splitext:

files = os.listdir('.')
extensions = [os.path.splitext(f)[1] for f in files]
if '.flac' in extensions:
  print 'FLAC files found!'

HTH!

-- 
John.

From alan.gauld at btinternet.com  Tue Dec  9 01:47:17 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 9 Dec 2008 00:47:17 -0000
Subject: [Tutor] list.index() question
References: <262679b50812081605s1888bf06vcbca2de976f89013@mail.gmail.com>
Message-ID: <ghkf6k$c07$1@ger.gmane.org>


"Damon Timm" <damontimm at gmail.com> wrote

> walk the directory path, I want to see if a directory contains any
> files ending in a certain type ... if it does, I wanna do some stuff

Check out the glob module.

> for dirpath, subFolders, files in os.walk(rootDir):
>     try:
>         i = files.index("*.flac") #how do I make it search for files
> that end in ".flac" ?

If yu call glob.glob() with the dirpath you will get a list of all
the flac files in the current dir.

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From kent37 at tds.net  Tue Dec  9 01:55:24 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 8 Dec 2008 19:55:24 -0500
Subject: [Tutor] list.index() question
In-Reply-To: <262679b50812081605s1888bf06vcbca2de976f89013@mail.gmail.com>
References: <262679b50812081605s1888bf06vcbca2de976f89013@mail.gmail.com>
Message-ID: <1c2a2c590812081655s53847e9er74f4f0e7db7377ee@mail.gmail.com>

On Mon, Dec 8, 2008 at 7:05 PM, Damon Timm <damontimm at gmail.com> wrote:
> Hi again!
>
> (Now that everyone was so helpful the first time you'll never get rid of me!)

That's fine, pretty soon you'll be answering other people's questions :-)

> I had a question about using the index() function on a list -- as I
> walk the directory path, I want to see if a directory contains any
> files ending in a certain type ... if it does, I wanna do some stuff
> ... if not, I would like to move on ... .

index() searches for a specific matching item, it doesn't have any
wildcard ability.

> for dirpath, subFolders, files in os.walk(rootDir):
>     try:
>         i = files.index("*.flac") #how do I make it search for files
> that end in ".flac" ?
>         for file in files:
>                #do some things in here to sort my files
>     except ValueError:
>         pass

I'm not sure what you want to do, but if you just want to operate on
files that end with .flac, you can just say
for file in files:
  if not file.endswith('.flac'):
    continue

though 'file' is not a good variable name, there is a builtin of that name.

> Basically: how do I make it match *.flac ?  I couldn't find anything
> on google (searching for "python index" just gets me a lot of indexes
> of python docs - wink)

There is actually an index:
http://docs.python.org/genindex.html

Kent

From damontimm at gmail.com  Tue Dec  9 02:17:15 2008
From: damontimm at gmail.com (Damon Timm)
Date: Mon, 8 Dec 2008 20:17:15 -0500
Subject: [Tutor] list.index() question
In-Reply-To: <1c2a2c590812081655s53847e9er74f4f0e7db7377ee@mail.gmail.com>
References: <262679b50812081605s1888bf06vcbca2de976f89013@mail.gmail.com>
	<1c2a2c590812081655s53847e9er74f4f0e7db7377ee@mail.gmail.com>
Message-ID: <262679b50812081717y11590b2eu2dbe37d30b9f8ea8@mail.gmail.com>

On Mon, Dec 8, 2008 at 7:55 PM, Kent Johnson <kent37 at tds.net> wrote:
> index() searches for a specific matching item, it doesn't have any
> wildcard ability.

Ah ha!

> There is actually an index:
> http://docs.python.org/genindex.html

Heh heh - and the info I was looking for is at:
http://docs.python.org/library/stdtypes.html#index-584 ... I've become
google dependent ... if it's not on google I don't know where to look.

Thanks for the .endswith() tip.

On 12/8/08 7:47 PM, Alan Gauld wrote:
> Check out the glob module.
>
>> for dirpath, subFolders, files in os.walk(rootDir):
>>     try:
>>         i = files.index("*.flac") #how do I make it search for files
>> that end in ".flac" ?
>
> If yu call glob.glob() with the dirpath you will get a list of all
> the flac files in the current dir.

Heading to check out glob.glob() now ...

On 12/8/08 7:29 PM, John Fouhy wrote:
> The fnmatch module will help here.  It basically implements unix-style
> filename patterns.  For example:
>
> import os
> import fnmatch
>
> files = os.listdir('.')
> flac_files = fnmatch(files, '*.flac')
>
> So, to test whether you have any flac files, you can just test whether
> fnmatch(files, '*.flac') is empty.
>
> If you wanted to roll your own solution (the fnmatch module is a bit
> obscure, I think), you could do something with os.path.splitext:
>
> files = os.listdir('.')
> extensions = [os.path.splitext(f)[1] for f in files]
> if '.flac' in extensions:
>   print 'FLAC files found!'

And then to look at fnmatch!

Thanks for the direction -- on my way ...

On 12/8/08 7:55 PM, Kent Johnson wrote:
> On Mon, Dec 8, 2008 at 7:05 PM, Damon Timm <damontimm at gmail.com> wrote:
>> Hi again!
>>
>> (Now that everyone was so helpful the first time you'll never get rid of me!)
>
> That's fine, pretty soon you'll be answering other people's questions :-)

Not quite there yet ... one day, maybe.  I can show people where the
index for index is!

Damon

From lie.1296 at gmail.com  Tue Dec  9 22:06:19 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Tue, 9 Dec 2008 21:06:19 +0000 (UTC)
Subject: [Tutor] Sorting a dictionary on a value in a list.
References: <8191FB37-C507-446C-933F-246C5073689D@gmail.com>
	<f90615120812031658g6b49d229y1b60cefc3d9f89b4@mail.gmail.com>
	<1c2a2c590812031742m57ed6f0av1b34fa8f6331a548@mail.gmail.com>
	<045316B5-CB8D-4C92-9CA4-E23FC5B3B08D@gmail.com>
	<ghddr6$15v$1@ger.gmane.org>
	<9A73889B-3727-4289-BDDE-43642B5267EB@gmail.com>
Message-ID: <ghmmka$80n$2@ger.gmane.org>

On Mon, 08 Dec 2008 08:55:40 -0800, Lawrence Wickline wrote:

> On Dec 6, 2008, at 12:41 AM, Lie Ryan wrote:
>>
>> In most cases, in processing involving networking, the bottleneck is
>> the
>> network speed itself. To speed things up by optimizing your own code
>> might not make your download significantly faster (getting 60 seconds
>> faster is great for scripts that usually runs for 70 seconds, but is a
>> waste of development time for scripts that usually run for 1 hour)
>>
>> Usually a multi-threading downloader might be a better chance to
>> improvement, especially for 1)  downloading from different site, 2) the
>> remote sites have speed limit, 3) you have faster download link than
>> the
>> server can gives
> 
> 
> In this particular case everything is on the local network. This is
> actually part of a hadoop map/reduce system I am learning, so reducing
> cpu is of high value. if network pull times become and issue the cluster
> can be expanded and the time between pulls can be  reduced. As of this
> morning I am being directed to make the reducer usable both in the
> mapper and then again as a reducer.  This has forced me to rework
> everything to work so that it can be called as a module.
> 

Just don't forget about the profile and cProfile module, it might reveal 
hidden bottlenecks.


From gmorris at serif.com  Wed Dec 10 13:48:38 2008
From: gmorris at serif.com (Gareth at Serif)
Date: Wed, 10 Dec 2008 04:48:38 -0800 (PST)
Subject: [Tutor]  MP3Info class usage
Message-ID: <20934673.post@talk.nabble.com>


Has anyone ever used MP3Info to retrieve the ID3 tags from an MP3?  It seems
to be a well written class that can access ID3 tags in v.1 or v.2, but I've
not used classes before and I'm struggling to figure out how to use it.

Given that, for testing purposses, I have a property called 'testfile' set
to the path of a valid MP3 file, I then try to output the artist name with
the following, where ID3v2 is a class defined in MP3Info:
song = ID3v2(testfile)
print '\nArtist is: %s' % (song.artist)

When I execute this script I get an error, "AttributeError: 'str' object has
no attribute 'seek'".  Is this a bug in the class or am I not using it
correctly?  Has anyone any better suggestions for retreiving ID3 tags from
an MP3 file using python?

Regards,
Gareth
-- 
View this message in context: http://www.nabble.com/MP3Info-class-usage-tp20934673p20934673.html
Sent from the Python - tutor mailing list archive at Nabble.com.


From tmz at pobox.com  Wed Dec 10 15:05:34 2008
From: tmz at pobox.com (Todd Zullinger)
Date: Wed, 10 Dec 2008 09:05:34 -0500
Subject: [Tutor] MP3Info class usage
In-Reply-To: <20934673.post@talk.nabble.com>
References: <20934673.post@talk.nabble.com>
Message-ID: <20081210140534.GM13722@inocybe.teonanacatl.org>

Gareth at Serif wrote:
> Has anyone any better suggestions for retreiving ID3 tags from an
> MP3 file using python?

I'd recommend eyeD3? and/or mutagen? for tag reading.  Both are pretty
easy to use.

? http://eyed3.nicfit.net/
? http://code.google.com/p/quodlibet/wiki/Development/Mutagen

-- 
Todd        OpenPGP -> KeyID: 0xBEAF0CE3 | URL: www.pobox.com/~tmz/pgp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A paranoid is someone who knows a little of what's going on.
    -- William S. Burroughs

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From damontimm at gmail.com  Wed Dec 10 15:12:46 2008
From: damontimm at gmail.com (Damon Timm)
Date: Wed, 10 Dec 2008 09:12:46 -0500
Subject: [Tutor] MP3Info class usage
In-Reply-To: <20081210140534.GM13722@inocybe.teonanacatl.org>
References: <20934673.post@talk.nabble.com>
	<20081210140534.GM13722@inocybe.teonanacatl.org>
Message-ID: <262679b50812100612v78d5b49fh1acb94d861249ebf@mail.gmail.com>

On 12/10/08, Todd Zullinger <tmz at pobox.com> wrote:
> I'd recommend eyeD3? and/or mutagen? for tag reading.  Both are pretty
> easy to use.

I would second eyeD3 -- I use the command line version and it is
pretty versatile.

D

>
> ? http://eyed3.nicfit.net/
> ? http://code.google.com/p/quodlibet/wiki/Development/Mutagen
>
> --
> Todd        OpenPGP -> KeyID: 0xBEAF0CE3 | URL: www.pobox.com/~tmz/pgp
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> A paranoid is someone who knows a little of what's going on.
>    -- William S. Burroughs
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>
>

From kent37 at tds.net  Wed Dec 10 15:20:25 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 10 Dec 2008 09:20:25 -0500
Subject: [Tutor] MP3Info class usage
In-Reply-To: <20934673.post@talk.nabble.com>
References: <20934673.post@talk.nabble.com>
Message-ID: <1c2a2c590812100620n396a6ecs5afa8fa2caf0e524@mail.gmail.com>

On Wed, Dec 10, 2008 at 7:48 AM, Gareth at Serif <gmorris at serif.com> wrote:

> Given that, for testing purposses, I have a property called 'testfile' set
> to the path of a valid MP3 file, I then try to output the artist name with
> the following, where ID3v2 is a class defined in MP3Info:
> song = ID3v2(testfile)
> print '\nArtist is: %s' % (song.artist)
>
> When I execute this script I get an error, "AttributeError: 'str' object has
> no attribute 'seek'".

The ID3v2 constructor wants a file object as a parameter, not a
string. It is trying to call testfile.seek() which causes the error
you see.

Try ID3v2(open(testfile))

Kent

From lie.1296 at gmail.com  Wed Dec 10 15:55:20 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Wed, 10 Dec 2008 14:55:20 +0000 (UTC)
Subject: [Tutor] MP3Info class usage
References: <20934673.post@talk.nabble.com>
Message-ID: <ghol8o$6ud$2@ger.gmane.org>

On Wed, 10 Dec 2008 04:48:38 -0800, Gareth at Serif wrote:

> Has anyone ever used MP3Info to retrieve the ID3 tags from an MP3?  It
> seems to be a well written class that can access ID3 tags in v.1 or v.2,
> but I've not used classes before and I'm struggling to figure out how to
> use it.
> 
> Given that, for testing purposses, I have a property called 'testfile'
> set to the path of a valid MP3 file, I then try to output the artist
> name with the following, where ID3v2 is a class defined in MP3Info: song
> = ID3v2(testfile)
> print '\nArtist is: %s' % (song.artist)
> 
> When I execute this script I get an error, "AttributeError: 'str' object
> has no attribute 'seek'".  Is this a bug in the class or am I not using
> it correctly?  Has anyone any better suggestions for retreiving ID3 tags
> from an MP3 file using python?
> 
> Regards,
> Gareth

You need to know about file interface. The testfile you gave is neither a 
file object nor a file-like object but a string while the function ID3v2 
expects a file or file-like object. In short, ID3v2 tries to call 
testfile.seek() which doesn't exists.


From jtp at nc.rr.com  Wed Dec 10 16:18:24 2008
From: jtp at nc.rr.com (James)
Date: Wed, 10 Dec 2008 10:18:24 -0500
Subject: [Tutor] sending html and text emails
Message-ID: <e107b4ff0812100718u722788e9r5ed0c646a9bd966@mail.gmail.com>

All,

I'm trying to figure out a way to send html email using Python. I've
found scripts such as the one in the link below:

http://www.stevecoursen.com/2008/10/sending-html-email-from-python.html/

These don't seem to work well. I took a (very) basic html page and had
the script in the page above read that page and then set up the text /
html email. When my client received the message it was filled with
visible html tags.

The ultimate goal is to have a script that displays a simple HTML
table that's easily readable by anyone using a client capable of
interpreting html emails.

Thoughts?

-j

From nephish at gmail.com  Wed Dec 10 19:23:48 2008
From: nephish at gmail.com (shawn bright)
Date: Wed, 10 Dec 2008 12:23:48 -0600
Subject: [Tutor] how to run a process forever
Message-ID: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>

Hey gents,

I have an interesting problem. I need to have a python script start
when a computer boots up, and i need it to run forever.
I also am going to run a script by cron that will check to see if the
process is running, if not, i need a python script to execute
the script.

What would be a good way to go about this?

A few ways are possible, just asking for what you guys might thing the
best solution is.

thanks,

shawn

From steve at alchemy.com  Wed Dec 10 19:28:37 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Wed, 10 Dec 2008 10:28:37 -0800
Subject: [Tutor] how to run a process forever
In-Reply-To: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>
References: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>
Message-ID: <20081210182837.GC87165@dragon.alchemy.com>

On Wed, Dec 10, 2008 at 12:23:48PM -0600, shawn bright wrote:
> Hey gents,
> 
> I have an interesting problem. I need to have a python script start
> when a computer boots up, and i need it to run forever.
> I also am going to run a script by cron that will check to see if the
> process is running, if not, i need a python script to execute
> the script.

Maybe I'm misunderstanding your meaning, but usually programs which do
this don't do anything unusual other than... well... simply run forever
in the background (launched from the startup scripts or cron, disassociated
from any TTY, of course).  A watchdog re-launcher cron script is also
not uncommon.

If your script isn't actively doing something it's good to put it to
sleep until some interesting event (or timer) wakes it up.

Was there something beyond that you were looking for?

-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From srilyk at gmail.com  Wed Dec 10 19:34:32 2008
From: srilyk at gmail.com (W W)
Date: Wed, 10 Dec 2008 12:34:32 -0600
Subject: [Tutor] how to run a process forever
In-Reply-To: <20081210182837.GC87165@dragon.alchemy.com>
References: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>
	<20081210182837.GC87165@dragon.alchemy.com>
Message-ID: <333efb450812101034h34afa1f3k8d9cd59d1c8199bf@mail.gmail.com>

while True:
is also a common way to make your program "run forever". Although you still
need to create some sleep/wait function or it will eat up your available
processes (so I'm told).

-HTH,
Wayne

On Wed, Dec 10, 2008 at 12:28 PM, Steve Willoughby <steve at alchemy.com>wrote:

> On Wed, Dec 10, 2008 at 12:23:48PM -0600, shawn bright wrote:
> > Hey gents,
> >
> > I have an interesting problem. I need to have a python script start
> > when a computer boots up, and i need it to run forever.
> > I also am going to run a script by cron that will check to see if the
> > process is running, if not, i need a python script to execute
> > the script.
>
> Maybe I'm misunderstanding your meaning, but usually programs which do
> this don't do anything unusual other than... well... simply run forever
> in the background (launched from the startup scripts or cron, disassociated
> from any TTY, of course).  A watchdog re-launcher cron script is also
> not uncommon.
>
> If your script isn't actively doing something it's good to put it to
> sleep until some interesting event (or timer) wakes it up.
>
> Was there something beyond that you were looking for?
>
> --
> Steve Willoughby    |  Using billion-dollar satellites
> steve at alchemy.com   |  to hunt for Tupperware.
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



-- 
To be considered stupid and to be told so is more painful than being called
gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness,
every vice, has found its defenders, its rhetoric, its ennoblement and
exaltation, but stupidity hasn't. - Primo Levi
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From nephish at gmail.com  Wed Dec 10 20:15:18 2008
From: nephish at gmail.com (shawn bright)
Date: Wed, 10 Dec 2008 13:15:18 -0600
Subject: [Tutor] how to run a process forever
In-Reply-To: <333efb450812101034h34afa1f3k8d9cd59d1c8199bf@mail.gmail.com>
References: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>
	<20081210182837.GC87165@dragon.alchemy.com>
	<333efb450812101034h34afa1f3k8d9cd59d1c8199bf@mail.gmail.com>
Message-ID: <384c93600812101115g3496fdb1x5b780ffbb65a9943@mail.gmail.com>

Sorry, was not very specific in my request.

say i have a script like

while 1:
    do_something_cool()
    time.sleep(2)

i am running this on a linux computer. How would i check that it is
running? (from cron part)
and how do i kick it off when i boot the computer? ( the init script part)

thanks for your responses.
shawn

On Wed, Dec 10, 2008 at 12:34 PM, W W <srilyk at gmail.com> wrote:
> while True:
> is also a common way to make your program "run forever". Although you still
> need to create some sleep/wait function or it will eat up your available
> processes (so I'm told).
> -HTH,
> Wayne
> On Wed, Dec 10, 2008 at 12:28 PM, Steve Willoughby <steve at alchemy.com>
> wrote:
>>
>> On Wed, Dec 10, 2008 at 12:23:48PM -0600, shawn bright wrote:
>> > Hey gents,
>> >
>> > I have an interesting problem. I need to have a python script start
>> > when a computer boots up, and i need it to run forever.
>> > I also am going to run a script by cron that will check to see if the
>> > process is running, if not, i need a python script to execute
>> > the script.
>>
>> Maybe I'm misunderstanding your meaning, but usually programs which do
>> this don't do anything unusual other than... well... simply run forever
>> in the background (launched from the startup scripts or cron,
>> disassociated
>> from any TTY, of course).  A watchdog re-launcher cron script is also
>> not uncommon.
>>
>> If your script isn't actively doing something it's good to put it to
>> sleep until some interesting event (or timer) wakes it up.
>>
>> Was there something beyond that you were looking for?
>>
>> --
>> Steve Willoughby    |  Using billion-dollar satellites
>> steve at alchemy.com   |  to hunt for Tupperware.
>> _______________________________________________
>> Tutor maillist  -  Tutor at python.org
>> http://mail.python.org/mailman/listinfo/tutor
>
>
>
> --
> To be considered stupid and to be told so is more painful than being called
> gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness,
> every vice, has found its defenders, its rhetoric, its ennoblement and
> exaltation, but stupidity hasn't. - Primo Levi
>

From steve at alchemy.com  Wed Dec 10 20:29:10 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Wed, 10 Dec 2008 11:29:10 -0800
Subject: [Tutor] how to run a process forever
In-Reply-To: <384c93600812101115g3496fdb1x5b780ffbb65a9943@mail.gmail.com>
References: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>
	<20081210182837.GC87165@dragon.alchemy.com>
	<333efb450812101034h34afa1f3k8d9cd59d1c8199bf@mail.gmail.com>
	<384c93600812101115g3496fdb1x5b780ffbb65a9943@mail.gmail.com>
Message-ID: <20081210192910.GG87165@dragon.alchemy.com>

On Wed, Dec 10, 2008 at 01:15:18PM -0600, shawn bright wrote:
> Sorry, was not very specific in my request.
> 
> say i have a script like
> 
> while 1:
>     do_something_cool()
>     time.sleep(2)

Ah, ok.  First of all, my preference would be to say "while True:"
there, seems more clear to me.  A more complex program might have
different "do this forever" logic, but an infinite loop is pretty
common as well.

The sleep is a very important step for making sure that the script
doesn't spin forever.  Better would be to sleep as long as practical,
or wake up on some event (assuming you don't just need this to run
something every set interval of time).

> i am running this on a linux computer. How would i check that it is
> running? (from cron part)

Typically you have your program write its PID to a file.  The cron
script can check that file and see if that process is still alive before
deciding to start another.

Or, you could just look at the processes and look for your script by
name.

Or any of a few other semaphore kinds of things (a file your script
touches periodically, and if it's more than n minutes old is a sign
your script has locked up/died is one simple example).

> and how do i kick it off when i boot the computer? ( the init script part)

Unix-like systems have a script run when the system is booted.  BSD
systems usually put this is /etc/rc.local.  Linux usually has a 
directory of scripts, one per application, in /etc/init.d, with symlinks
from /etc/rc<n>.d indicating which run level <n> you want that service
started.  See your distro's documentation for details specific to your
flavor of Linux.

You'll want to run it in the background without any associated terminal.
In a Bourne-type shell, this usually looks like this:

     /path/to/myscript </dev/null >/dev/null 2>&1 &

-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From nephish at gmail.com  Wed Dec 10 21:06:38 2008
From: nephish at gmail.com (shawn bright)
Date: Wed, 10 Dec 2008 14:06:38 -0600
Subject: [Tutor] how to run a process forever
In-Reply-To: <20081210192910.GG87165@dragon.alchemy.com>
References: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>
	<20081210182837.GC87165@dragon.alchemy.com>
	<333efb450812101034h34afa1f3k8d9cd59d1c8199bf@mail.gmail.com>
	<384c93600812101115g3496fdb1x5b780ffbb65a9943@mail.gmail.com>
	<20081210192910.GG87165@dragon.alchemy.com>
Message-ID: <384c93600812101206j8728394qf89c92c4ae1056da@mail.gmail.com>

cool thanks for the help.
-shawn

On Wed, Dec 10, 2008 at 1:29 PM, Steve Willoughby <steve at alchemy.com> wrote:
> On Wed, Dec 10, 2008 at 01:15:18PM -0600, shawn bright wrote:
>> Sorry, was not very specific in my request.
>>
>> say i have a script like
>>
>> while 1:
>>     do_something_cool()
>>     time.sleep(2)
>
> Ah, ok.  First of all, my preference would be to say "while True:"
> there, seems more clear to me.  A more complex program might have
> different "do this forever" logic, but an infinite loop is pretty
> common as well.
>
> The sleep is a very important step for making sure that the script
> doesn't spin forever.  Better would be to sleep as long as practical,
> or wake up on some event (assuming you don't just need this to run
> something every set interval of time).
>
>> i am running this on a linux computer. How would i check that it is
>> running? (from cron part)
>
> Typically you have your program write its PID to a file.  The cron
> script can check that file and see if that process is still alive before
> deciding to start another.
>
> Or, you could just look at the processes and look for your script by
> name.
>
> Or any of a few other semaphore kinds of things (a file your script
> touches periodically, and if it's more than n minutes old is a sign
> your script has locked up/died is one simple example).
>
>> and how do i kick it off when i boot the computer? ( the init script part)
>
> Unix-like systems have a script run when the system is booted.  BSD
> systems usually put this is /etc/rc.local.  Linux usually has a
> directory of scripts, one per application, in /etc/init.d, with symlinks
> from /etc/rc<n>.d indicating which run level <n> you want that service
> started.  See your distro's documentation for details specific to your
> flavor of Linux.
>
> You'll want to run it in the background without any associated terminal.
> In a Bourne-type shell, this usually looks like this:
>
>     /path/to/myscript </dev/null >/dev/null 2>&1 &
>
> --
> Steve Willoughby    |  Using billion-dollar satellites
> steve at alchemy.com   |  to hunt for Tupperware.
>

From tiagosaboga at gmail.com  Thu Dec 11 00:56:13 2008
From: tiagosaboga at gmail.com (Tiago Saboga)
Date: Wed, 10 Dec 2008 21:56:13 -0200
Subject: [Tutor] how to run a process forever
In-Reply-To: <20081210192910.GG87165@dragon.alchemy.com>
References: <384c93600812101023o3715f5aao1940bb09c79b8255@mail.gmail.com>
	<20081210182837.GC87165@dragon.alchemy.com>
	<333efb450812101034h34afa1f3k8d9cd59d1c8199bf@mail.gmail.com>
	<384c93600812101115g3496fdb1x5b780ffbb65a9943@mail.gmail.com>
	<20081210192910.GG87165@dragon.alchemy.com>
Message-ID: <20081210235613.GB1388@localdomain>

On Wed, Dec 10, 2008 at 11:29:10AM -0800, Steve Willoughby wrote:
> On Wed, Dec 10, 2008 at 01:15:18PM -0600, shawn bright wrote:
> > i am running this on a linux computer. How would i check that it is
> > running? (from cron part)
> 
> Typically you have your program write its PID to a file.  The cron
> script can check that file and see if that process is still alive before
> deciding to start another.

If you are in a debian-based system, see start-stop-daemon (possibly
available in other distros too).

Tiago Saboga.

From kent37 at tds.net  Thu Dec 11 04:18:37 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 10 Dec 2008 22:18:37 -0500
Subject: [Tutor] sending html and text emails
In-Reply-To: <e107b4ff0812100718u722788e9r5ed0c646a9bd966@mail.gmail.com>
References: <e107b4ff0812100718u722788e9r5ed0c646a9bd966@mail.gmail.com>
Message-ID: <1c2a2c590812101918i690bd168je0f8b0edde24e5d6@mail.gmail.com>

On Wed, Dec 10, 2008 at 10:18 AM, James <jtp at nc.rr.com> wrote:
> All,
>
> I'm trying to figure out a way to send html email using Python. I've
> found scripts such as the one in the link below:
>
> http://www.stevecoursen.com/2008/10/sending-html-email-from-python.html/
>
> These don't seem to work well. I took a (very) basic html page and had
> the script in the page above read that page and then set up the text /
> html email. When my client received the message it was filled with
> visible html tags.
>
> The ultimate goal is to have a script that displays a simple HTML
> table that's easily readable by anyone using a client capable of
> interpreting html emails.

It might help to see your code, if it is different at all from what is
on that page. What was printed?

Here is a redacted version of a function that worked for me. This
sends HTML only - no text part:

from email.mime.text import MIMEText
from email.Utils import formatdate

def emailReport():

    report = ... # Get HTML text from somewhere

    msg = MIMEText(report, 'html', 'utf-8')

    msg['Subject'] = 'report'
    msg['From'] = 'me at example.com'
    msg['To'] = 'you at example.com'
    msg['Date'] = formatdate()

    server = smtplib.SMTP(settings.EMAIL_HOST, settings.EMAIL_PORT)
    server.sendmail('me at example.com', 'you at example.com', msg.as_string())

    try:
        server.quit()
    except:
         return

Kent

From vadud3 at gmail.com  Thu Dec 11 17:49:16 2008
From: vadud3 at gmail.com (Asif Iqbal)
Date: Thu, 11 Dec 2008 11:49:16 -0500
Subject: [Tutor] MIME parser
Message-ID: <a60f25fc0812110849y4d03e9ffl517907fe0dded85f@mail.gmail.com>

I am looking for a way to feed a message from stdin to a python based
mime parser, detach all attachments and drop them to a dir, and then
send the email to the recipient.  The attachment(s) will be replaced
by an URL to a link.

So basically decouple the attachments (>1MB in size) and modify the
body by inserting an URL in the footer.

Has anyone done anything like this?


-- 
Asif Iqbal
PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu

From ravikondamuru at gmail.com  Thu Dec 11 19:04:14 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Thu, 11 Dec 2008 10:04:14 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
Message-ID: <36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>

Hi,
I am writing a script to read list output from a C executable. How should c
program be written so that python can read the output as a list?
Any pointers to info on this appreciated.
thanks,
Ravi.
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From bgailer at gmail.com  Thu Dec 11 19:19:01 2008
From: bgailer at gmail.com (bob gailer)
Date: Thu, 11 Dec 2008 13:19:01 -0500
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
Message-ID: <49415995.4040409@gmail.com>

Ravi Kondamuru wrote:
> Hi,
> I am writing a script to read list output from a C executable. How 
> should c program be written so that python can read the output as a list?
> Any pointers to info on this appreciated.

Funny that a C programmer is asking for pointers, when C has lots of 
pointers and Python has none. <chuckle>

Python I/O reads strings. So you must encode the list in some manner 
into a string and decode it into a list in the Python program.

Take a look as json. http://www.json.org/

There are links to C and Python. You should be able there to find how to 
encode in C and decode in Python.

You could "roll your own" encoding" but I think json would be easier.

Remember to reply-all so a copy goes to the list.

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From steve at alchemy.com  Thu Dec 11 19:27:22 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Thu, 11 Dec 2008 10:27:22 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
Message-ID: <49415B8A.3080701@alchemy.com>

Ravi Kondamuru wrote:
> Hi,
> I am writing a script to read list output from a C executable. How 
> should c program be written so that python can read the output as a list?
> Any pointers to info on this appreciated.

The possibilities are truly wide open on this.  Python can read a 
variety of standard formats (and of course can have custom code to read 
anything.  Depending on what the data involved actually are, you need to 
decide what format works best.

A simple approach is to have the C program write simple CSV output, and 
use Python's csv module to read it.  A more complex solution might be to 
use XML.  There are approximately 52,495,102 other possibilities 
available too, so you have lots of room to work out what's best for your 
  application.  More specific information on what you're trying to 
accomplish would help narrow it down as well.

From ravikondamuru at gmail.com  Thu Dec 11 19:29:10 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Thu, 11 Dec 2008 10:29:10 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <49415995.4040409@gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415995.4040409@gmail.com>
Message-ID: <36601b010812111029i32957114ve358cd2dc512afa9@mail.gmail.com>

I am expecting these lists to be huge and was hoping to avoid re-parsing in
python. Any way for the c program to return a list that python can directly
use.
Thanks for the pointer to json :) I am going to explore and evaluate
re-parsing overhead.
thanks,
Ravi.

On Thu, Dec 11, 2008 at 10:19 AM, bob gailer <bgailer at gmail.com> wrote:

> Ravi Kondamuru wrote:
>
>> Hi,
>> I am writing a script to read list output from a C executable. How should
>> c program be written so that python can read the output as a list?
>> Any pointers to info on this appreciated.
>>
>
> Funny that a C programmer is asking for pointers, when C has lots of
> pointers and Python has none. <chuckle>
>
> Python I/O reads strings. So you must encode the list in some manner into a
> string and decode it into a list in the Python program.
>
> Take a look as json. http://www.json.org/
>
> There are links to C and Python. You should be able there to findThats how
> to encode in C and decode in Python.
>
> You could "roll your own" encoding" but I think json would be easier.
>
> Remember to reply-all so a copy goes to the list.
>
> --
> Bob Gailer
> Chapel Hill NC 919-636-4239
>
>
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From ravikondamuru at gmail.com  Thu Dec 11 19:35:14 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Thu, 11 Dec 2008 10:35:14 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <49415B8A.3080701@alchemy.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
Message-ID: <36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>

I am trying to read a binary log file to extract system counters. These
counters will then be used to generate web-based graphs using the
chart-director api in python. For extracting the counters I planning to
write a program in C to read and give the output as lists for use by
chart-director. If possible i would like to do the parsing of data only once
in C on the log file and pass the processed output for direct use by
python.
I have thought about having to populate a database first but will prefer to
avoid having another intermediate datastore (apart from the log file).

thanks,
Ravi.

On Thu, Dec 11, 2008 at 10:27 AM, Steve Willoughby <steve at alchemy.com>wrote:

> Ravi Kondamuru wrote:
>
>> Hi,
>> I am writing a script to read list output from a C executable. How should
>> c program be written so that python can read the output as a list?
>> Any pointers to info on this appreciated.
>>
>
> The possibilities are truly wide open on this.  Python can read a variety
> of standard formats (and of course can have custom code to read anything.
>  Depending on what the data involved actually are, you need to decide what
> format works best.
>
> A simple approach is to have the C program write simple CSV output, and use
> Python's csv module to read it.  A more complex solution might be to use
> XML.  There are approximately 52,495,102 other possibilities available too,
> so you have lots of room to work out what's best for your  application.
>  More specific information on what you're trying to accomplish would help
> narrow it down as well.
>
-------------- next part --------------
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From bgailer at gmail.com  Thu Dec 11 19:39:40 2008
From: bgailer at gmail.com (bob gailer)
Date: Thu, 11 Dec 2008 13:39:40 -0500
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111029i32957114ve358cd2dc512afa9@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	
	<49415995.4040409@gmail.com>
	<36601b010812111029i32957114ve358cd2dc512afa9@mail.gmail.com>
Message-ID: <49415E6C.7080502@gmail.com>

Ravi Kondamuru wrote:
> I am expecting these lists to be huge and was hoping to avoid 
> re-parsing in python. Any way for the c program to return a list that 
> python can directly use.

Not as far as I know. Lists in Python are internal objects. If you were 
able to package the C and Python programs together (C extension, SWIG, 
...???) then you could write the Python object directly from the C program.

What will the Python program do with the lists? And what does huge mean. 
Does it have to be a list? Is performance an issue or storage space or what?

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From bgailer at gmail.com  Thu Dec 11 19:41:25 2008
From: bgailer at gmail.com (bob gailer)
Date: Thu, 11 Dec 2008 13:41:25 -0500
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
Message-ID: <49415ED5.3030902@gmail.com>

Ravi Kondamuru wrote:
> I am trying to read a binary log file to extract system counters. 
> These counters will then be used to generate web-based graphs using 
> the chart-director api in python. For extracting the counters I 
> planning to write a program in C to read and give the output as lists 
> for use by chart-director. If possible i would like to do the parsing 
> of data only once in C on the log file and pass the processed output 
> for direct use by python. 
>
> I have thought about having to populate a database first but will 
> prefer to avoid having another intermediate datastore (apart from the 
> log file).

As you might guess I was typing my response before reading the above. So 
you answered my question.

NOW: why not read and parse the log file in Python?

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From steve at alchemy.com  Thu Dec 11 19:44:52 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Thu, 11 Dec 2008 10:44:52 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111029i32957114ve358cd2dc512afa9@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	<49415995.4040409@gmail.com>
	<36601b010812111029i32957114ve358cd2dc512afa9@mail.gmail.com>
Message-ID: <49415FA4.4020807@alchemy.com>

Ravi Kondamuru wrote:
> I am expecting these lists to be huge and was hoping to avoid re-parsing 
> in python. Any way for the c program to return a list that python can 

Mind if I ask the obvious question here?  Why are you wanting to avoid 
parsing in Python?  Any time you have one program (in any language) 
leave data behind for another program to consume, you're going to have 
some level of interpretation on the data, whether you're reading raw 
bytes and assuming you know how to put them together again or parsing 
ASCII characters or whatever.

Try something simple first and see if you get reasonable performance 
from it before you get too paranoid about avoiding something that might 
not be where you need to focus your attention.  Optimizing too early in 
the development effort often leads to wasted time on the things that 
surprisingly don't contribute to the real performance issues in a program.

If you're output is binary data (like a stream of bytes or words), 
Python can read that with a small bit of code to put those bytes into 
integer values in a list.  I'd suggest something like CSV as a first 
try, though, since that way the data will be intelligible for debugging 
purposes, leaves the possibility open for other scripts to read and 
alter the data too, and is very simple for Python to read via standard 
library modules too.

> directly use.
> Thanks for the pointer to json :) I am going to explore and evaluate 
> re-parsing overhead.
> thanks,
> Ravi.
> 
> On Thu, Dec 11, 2008 at 10:19 AM, bob gailer <bgailer at gmail.com 
> <mailto:bgailer at gmail.com>> wrote:
> 
>     Ravi Kondamuru wrote:
> 
>         Hi,
>         I am writing a script to read list output from a C executable.
>         How should c program be written so that python can read the
>         output as a list?
>         Any pointers to info on this appreciated.
> 
> 
>     Funny that a C programmer is asking for pointers, when C has lots of
>     pointers and Python has none. <chuckle>
> 
>     Python I/O reads strings. So you must encode the list in some manner
>     into a string and decode it into a list in the Python program.
> 
>     Take a look as json. http://www.json.org/
> 
>     There are links to C and Python. You should be able there to
>     findThats how to encode in C and decode in Python.
> 
>     You could "roll your own" encoding" but I think json would be easier.
> 
>     Remember to reply-all so a copy goes to the list.
> 
>     -- 
>     Bob Gailer
>     Chapel Hill NC 919-636-4239
> 
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor


From steve at alchemy.com  Thu Dec 11 19:45:51 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Thu, 11 Dec 2008 10:45:51 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
Message-ID: <49415FDF.3080601@alchemy.com>

Ravi Kondamuru wrote:
> I am trying to read a binary log file to extract system counters. These 
> counters will then be used to generate web-based graphs using the 
> chart-director api in python. For extracting the counters I planning to 
> write a program in C to read and give the output as lists for use by 
> chart-director. If possible i would like to do the parsing of data only 
> once in C on the log file and pass the processed output for direct use 
> by python. 

Wait..
Why not have Python read the binary log file itself, parse it and make 
the API calls right there?  Why do you even need the C program?


> 
> I have thought about having to populate a database first but will prefer 
> to avoid having another intermediate datastore (apart from the log file).
> 
> thanks,
> Ravi.
> 
> On Thu, Dec 11, 2008 at 10:27 AM, Steve Willoughby <steve at alchemy.com 
> <mailto:steve at alchemy.com>> wrote:
> 
>     Ravi Kondamuru wrote:
> 
>         Hi,
>         I am writing a script to read list output from a C executable.
>         How should c program be written so that python can read the
>         output as a list?
>         Any pointers to info on this appreciated.
> 
> 
>     The possibilities are truly wide open on this.  Python can read a
>     variety of standard formats (and of course can have custom code to
>     read anything.  Depending on what the data involved actually are,
>     you need to decide what format works best.
> 
>     A simple approach is to have the C program write simple CSV output,
>     and use Python's csv module to read it.  A more complex solution
>     might be to use XML.  There are approximately 52,495,102 other
>     possibilities available too, so you have lots of room to work out
>     what's best for your  application.  More specific information on
>     what you're trying to accomplish would help narrow it down as well.
> 
> 


From ravikondamuru at gmail.com  Thu Dec 11 19:59:14 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Thu, 11 Dec 2008 10:59:14 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <49415FDF.3080601@alchemy.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
	<49415FDF.3080601@alchemy.com>
Message-ID: <36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>

Reasons for C:
1. The log files I am working are 60-100MB files. I *assumed* using C will
reduce the parse time.
2. The records themselves are variable length and hence was concerned about
the complexity for implementation in python.
3. Since I am not using a database, each request to refresh the graph
(changing time duration for display) will have to re-parse the file all over
again. And hence speed in parsing the log is important.

Hope that explains
thanks,
Ravi.

On Thu, Dec 11, 2008 at 10:45 AM, Steve Willoughby <steve at alchemy.com>wrote:

> Ravi Kondamuru wrote:
>
>> I am trying to read a binary log file to extract system counters. These
>> counters will then be used to generate web-based graphs using the
>> chart-director api in python. For extracting the counters I planning to
>> write a program in C to read and give the output as lists for use by
>> chart-director. If possible i would like to do the parsing of data only once
>> in C on the log file and pass the processed output for direct use by python.
>>
>>
>
> Wait..
> Why not have Python read the binary log file itself, parse it and make the
> API calls right there?  Why do you even need the C program?
>
>
>
>> I have thought about having to populate a database first but will prefer
>> to avoid having another intermediate datastore (apart from the log file).
>>
>> thanks,
>> Ravi.
>>
>> On Thu, Dec 11, 2008 at 10:27 AM, Steve Willoughby <steve at alchemy.com<mailto:
>> steve at alchemy.com>> wrote:
>>
>>    Ravi Kondamuru wrote:
>>
>>        Hi,
>>        I am writing a script to read list output from a C executable.
>>        How should c program be written so that python can read the
>>        output as a list?
>>        Any pointers to info on this appreciated.
>>
>>
>>    The possibilities are truly wide open on this.  Python can read a
>>    variety of standard formats (and of course can have custom code to
>>    read anything.  Depending on what the data involved actually are,
>>    you need to decide what format works best.
>>
>>    A simple approach is to have the C program write simple CSV output,
>>    and use Python's csv module to read it.  A more complex solution
>>    might be to use XML.  There are approximately 52,495,102 other
>>    possibilities available too, so you have lots of room to work out
>>    what's best for your  application.  More specific information on
>>    what you're trying to accomplish would help narrow it down as well.
>>
>>
>>
>
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From denis.spir at free.fr  Thu Dec 11 20:16:46 2008
From: denis.spir at free.fr (spir)
Date: Thu, 11 Dec 2008 20:16:46 +0100
Subject: [Tutor] [Fwd: Re:  reading output from a c executable.]
Message-ID: <4941671E.1040400@free.fr>


Ravi Kondamuru a ?crit :
> I am trying to read a binary log file to extract system counters. These
> counters will then be used to generate web-based graphs using the
> chart-director api in python. For extracting the counters I planning to
> write a program in C to read and give the output as lists for use by
> chart-director. If possible i would like to do the parsing of data onlyonce
> in C on the log file and pass the processed output for direct use by
> python.
> I have thought about having to populate a database first but will prefer to
> avoid having another intermediate datastore (apart from the log file).
> 
> thanks,
> Ravi.
> 
> On Thu, Dec 11, 2008 at 10:27 AM, Steve Willoughby <steve at alchemy.com>wrote:
> 
>> Ravi Kondamuru wrote:
>>
>>> Hi,
>>> I am writing a script to read list output from a C executable. How should
>>> c program be written so that python can read the output as a list?
>>> Any pointers to info on this appreciated.
>>>
>> The possibilities are truly wide open on this.  Python can read a variety
>> of standard formats (and of course can have custom code to read anything.
>>  Depending on what the data involved actually are, you need to decide what
>> format works best.
>>
>> A simple approach is to have the C program write simple CSV output, and use
>> Python's csv module to read it.  A more complex solution might be to use
>> XML.  There are approximately 52,495,102 other possibilities availabletoo,
>> so you have lots of room to work out what's best for your  application.
>>  More specific information on what you're trying to accomplish would help
>> narrow it down as well.

What type are these system counters? If you want to avoid reparsing in python,
why not let C write a valid python literal, then simply import? (depends on
what "huge" means for you). Assuming they are ints:
=========
counters.py:
counters = [
123,
456,
789,
...
]
=======
prog.py:
from counters import counters

denis




From zstumgoren at gmail.com  Thu Dec 11 20:31:39 2008
From: zstumgoren at gmail.com (Serdar Tumgoren)
Date: Thu, 11 Dec 2008 14:31:39 -0500
Subject: [Tutor] advice on regex matching for dates?
Message-ID: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>

Hey everyone,

I was wondering if there is a way to use the datetime module to check for
variations on a month name when performing a regex match?

In the script below, I created a regex pattern that checks for dates in the
following pattern:  "August 31, 2007". If there's a match, I can then print
the capture date and the line from which it was extracted.

While it works in this isolated case, it struck me as not very flexible.
What happens when I inevitably get data that has dates formatted in a
different way? Do I have to create some type of library that contains
variations on each month name (i.e. - January, Jan., 01, 1...) and use that
to parse each line?

Or is there some way to use datetime to check for date patterns when using
regex? Is there a "best practice" in this area that I'm unaware of in this
area?

Apologies if this question has been answered elsewhere. I wasn't sure how to
research this topic (beyond standard datetime docs), but I'd be happy to RTM
if someone can point me to some resources.

Any suggestions are welcome (including optimizations of the code below).

Regards,
Serdar

#!/usr/bin/env python

import re, sys

sourcefile = open(sys.argv[1],'r')

pattern =
re.compile(r'(?P<month>January|February|March|April|May|June|July|August|September|October|November|December)\s(?P<day>\d{1,2}),\s(?P<year>\d{4})')

pattern2 = re.compile(r'Return to List')

counter = 0

for line in sourcefile:
    x = pattern.search(line)
    break_point = pattern2.match(line)

    if x:
        counter +=1
        print "%s %d, %d <== %s" % ( x.group('month'), int(x.group('day')),
int(x.group('year')), line ),
    elif break_point:
        break

print counter
sourcefile.close()
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From steve at alchemy.com  Thu Dec 11 20:34:45 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Thu, 11 Dec 2008 11:34:45 -0800
Subject: [Tutor] [Fwd: Re:  reading output from a c executable.]
In-Reply-To: <4941671E.1040400@free.fr>
References: <4941671E.1040400@free.fr>
Message-ID: <49416B55.6080306@alchemy.com>

With the amount of information provided so far, I'd say you need to step 
back and question your initial assumptions.  Python shouldn't have a 
great deal of trouble reading variable-length binary data blocks, and 
the overhead of doing that is probably a lot less than it would be to 
have another program read that, output some intermediate format, and 
then have the Python script parse that (and whether you're writing code 
yourself, or blindly eval()ing source created by the C program, or 
reading some other format, it's *still* having to do that).

My recommendation: have the Python script read the binary data directly 
and act upon it, and avoid all the overhead and extra steps you're 
trying to design into your solution here.

If that doesn't run fast enough, consider coding a small file-reading 
module in C, *as a C-implemented Python module*, and import that into 
your program.  But try it in plain Python first and see what it's like.

From kent37 at tds.net  Thu Dec 11 21:11:50 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 11 Dec 2008 15:11:50 -0500
Subject: [Tutor] advice on regex matching for dates?
In-Reply-To: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>
References: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>
Message-ID: <1c2a2c590812111211r2ea8dee3r1b3d5dab4699448d@mail.gmail.com>

On Thu, Dec 11, 2008 at 2:31 PM, Serdar Tumgoren <zstumgoren at gmail.com> wrote:
> Hey everyone,
>
> I was wondering if there is a way to use the datetime module to check for
> variations on a month name when performing a regex match?

Parsing arbitrary dates is hard, in fact the most general case is not
solvable since 7/8/07 could refer to July 8 or August 7 and the
century must be guessed.

The only approach I know of is to try the formats you expect until you
find one that works. Mark Pilgrim's feedparser has a pretty robust
date parser you might look at; look at the _parse_date() function in
this module:
http://code.google.com/p/feedparser/source/browse/trunk/feedparser/feedparser.py

Kent

From vadud3 at gmail.com  Thu Dec 11 18:25:26 2008
From: vadud3 at gmail.com (Asif Iqbal)
Date: Thu, 11 Dec 2008 17:25:26 +0000
Subject: [Tutor] MIME parser
In-Reply-To: <a60f25fc0812110849y4d03e9ffl517907fe0dded85f@mail.gmail.com>
References: <a60f25fc0812110849y4d03e9ffl517907fe0dded85f@mail.gmail.com>
Message-ID: <20081211172525.GC21103@qwestip.net>

On Thu, Dec 11, 2008 at 11:49:16AM, Asif Iqbal wrote:
> I am looking for a way to feed a message from stdin to a python based
> mime parser, detach all attachments and drop them to a dir, and then
> send the email to the recipient.  The attachment(s) will be replaced
> by an URL to a link.
> 
> So basically decouple the attachments (>1MB in size) and modify the
> body by inserting an URL in the footer.
> 
> Has anyone done anything like this?
> 

I am looking at email pkg. Now I need to find a way to feed the msg
from stdin and then detach all attachments and update the body with 
urls pointing to attachments

> 

-- 
Asif Iqbal
Google Chat: vadud3 at gmail.com
PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?

From ravikondamuru at gmail.com  Thu Dec 11 22:36:41 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Thu, 11 Dec 2008 13:36:41 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
	<49415FDF.3080601@alchemy.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
Message-ID: <36601b010812111336k42667f9bq4f8da9582cac4c43@mail.gmail.com>

This was a great info exchange for me.
I am going to try out the all-python solution and see how it works out.
thank you all,
Ravi.

On Thu, Dec 11, 2008 at 10:59 AM, Ravi Kondamuru <ravikondamuru at gmail.com>wrote:

> Reasons for C:
> 1. The log files I am working are 60-100MB files. I *assumed* using C will
> reduce the parse time.
> 2. The records themselves are variable length and hence was concerned about
> the complexity for implementation in python.
> 3. Since I am not using a database, each request to refresh the graph
> (changing time duration for display) will have to re-parse the file all over
> again. And hence speed in parsing the log is important.
>
> Hope that explains
> thanks,
> Ravi.
>
>
> On Thu, Dec 11, 2008 at 10:45 AM, Steve Willoughby <steve at alchemy.com>wrote:
>
>> Ravi Kondamuru wrote:
>>
>>> I am trying to read a binary log file to extract system counters. These
>>> counters will then be used to generate web-based graphs using the
>>> chart-director api in python. For extracting the counters I planning to
>>> write a program in C to read and give the output as lists for use by
>>> chart-director. If possible i would like to do the parsing of data only once
>>> in C on the log file and pass the processed output for direct use by python.
>>>
>>>
>>
>> Wait..
>> Why not have Python read the binary log file itself, parse it and make the
>> API calls right there?  Why do you even need the C program?
>>
>>
>>
>>> I have thought about having to populate a database first but will prefer
>>> to avoid having another intermediate datastore (apart from the log file).
>>>
>>> thanks,
>>> Ravi.
>>>
>>> On Thu, Dec 11, 2008 at 10:27 AM, Steve Willoughby <steve at alchemy.com<mailto:
>>> steve at alchemy.com>> wrote:
>>>
>>>    Ravi Kondamuru wrote:
>>>
>>>        Hi,
>>>        I am writing a script to read list output from a C executable.
>>>        How should c program be written so that python can read the
>>>        output as a list?
>>>        Any pointers to info on this appreciated.
>>>
>>>
>>>    The possibilities are truly wide open on this.  Python can read a
>>>    variety of standard formats (and of course can have custom code to
>>>    read anything.  Depending on what the data involved actually are,
>>>    you need to decide what format works best.
>>>
>>>    A simple approach is to have the C program write simple CSV output,
>>>    and use Python's csv module to read it.  A more complex solution
>>>    might be to use XML.  There are approximately 52,495,102 other
>>>    possibilities available too, so you have lots of room to work out
>>>    what's best for your  application.  More specific information on
>>>    what you're trying to accomplish would help narrow it down as well.
>>>
>>>
>>>
>>
>
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From bryan.fodness at gmail.com  Thu Dec 11 22:34:30 2008
From: bryan.fodness at gmail.com (Bryan Fodness)
Date: Thu, 11 Dec 2008 16:34:30 -0500
Subject: [Tutor] no attribute
Message-ID: <fbf64d2b0812111334t7a2b5ddep5182007a6e7cb47c@mail.gmail.com>

I am trying to change values in a file.  The following code does not seem to
find the attribute.

def anonymize(obj, attr):
    try:
        obj.attr = 'Anonymize'
    except AttributeError:
        pass

for fname in os.listdir(os.curdir):
    plan=ReadFile(fname)
    anonymize(plan, 'Name')

It seems to be the obj.attr in the function.  Can someone explain what I am
doing wrong?

Bryan
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From alan.gauld at btinternet.com  Thu Dec 11 22:56:19 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Thu, 11 Dec 2008 21:56:19 -0000
Subject: [Tutor] no attribute
References: <fbf64d2b0812111334t7a2b5ddep5182007a6e7cb47c@mail.gmail.com>
Message-ID: <ghs2a5$75b$1@ger.gmane.org>


"Bryan Fodness" <bryan.fodness at gmail.com> wrote

>I am trying to change values in a file.  The following code does not 
>seem to
> find the attribute.
>
> def anonymize(obj, attr):
>    try:
>        obj.attr = 'Anonymize'
>    except AttributeError:
>        pass

This code is looking for an attribute of obj called attr
It is not using the name of attr stored in the attr parameter.

To do that you will need to use the setattr function.

HTH


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From denis.spir at free.fr  Thu Dec 11 23:38:52 2008
From: denis.spir at free.fr (spir)
Date: Thu, 11 Dec 2008 23:38:52 +0100
Subject: [Tutor] advice on regex matching for dates?
In-Reply-To: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>
References: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>
Message-ID: <4941967C.2010504@free.fr>

Serdar Tumgoren a ?crit :
> Hey everyone,
> 
> I was wondering if there is a way to use the datetime module to check for
> variations on a month name when performing a regex match?
> 
> In the script below, I created a regex pattern that checks for dates in the
> following pattern:  "August 31, 2007". If there's a match, I can then print
> the capture date and the line from which it was extracted.
> 
> While it works in this isolated case, it struck me as not very flexible.
> What happens when I inevitably get data that has dates formatted in a
> different way? Do I have to create some type of library that contains
> variations on each month name (i.e. - January, Jan., 01, 1...) and use that
> to parse each line?
> 
> Or is there some way to use datetime to check for date patterns when using
> regex? Is there a "best practice" in this area that I'm unaware of in this
> area?
> 
> Apologies if this question has been answered elsewhere. I wasn't sure how to
> research this topic (beyond standard datetime docs), but I'd be happy to RTM
> if someone can point me to some resources.
> 
> Any suggestions are welcome (including optimizations of the code below).
> 
> Regards,
> Serdar
> 
> #!/usr/bin/env python
> 
> import re, sys
> 
> sourcefile = open(sys.argv[1],'r')
> 
> pattern =
> re.compile(r'(?P<month>January|February|March|April|May|June|July|August|September|October|November|December)\s(?P<day>\d{1,2}),\s(?P<year>\d{4})')
> 
> pattern2 = re.compile(r'Return to List')
> 
> counter = 0
> 
> for line in sourcefile:
>     x = pattern.search(line)
>     break_point = pattern2.match(line)
> 
>     if x:
>         counter +=1
>         print "%s %d, %d <== %s" % ( x.group('month'), int(x.group('day')),
> int(x.group('year')), line ),
>     elif break_point:
>         break
> 
> print counter
> sourcefile.close()

I just found a simple, but nice, trick to make regexes less unlegible. Using 
substrings to represent sub-patterns. E.g. instead of:

p = 
re.compile(r'(?P<month>January|February|March|April|May|June|July|August|September|October|November|December)\s(?P<day>\d{1,2}),\s(?P<year>\d{4})')

write first:

month = 
r'(?P<month>January|February|March|April|May|June|July|August|September|October|November|December)'
day = r'(?P<day>\d{1,2})'
year = r'(?P<year>\d{4})'

then:
p = re.compile( r"%s\s%s,\s%s" % (month,day,year) )
or even:
p = re.compile( r"%(month)s\s%(day)s,\s%(year)s" % 
{'month':month,'day':day,'year':year} )

denis



From john at fouhy.net  Thu Dec 11 23:45:56 2008
From: john at fouhy.net (John Fouhy)
Date: Fri, 12 Dec 2008 11:45:56 +1300
Subject: [Tutor] advice on regex matching for dates?
In-Reply-To: <4941967C.2010504@free.fr>
References: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>
	<4941967C.2010504@free.fr>
Message-ID: <5e58f2e40812111445v5b1c2f7ehe98cccf0c207c270@mail.gmail.com>

On 12/12/2008, spir <denis.spir at free.fr> wrote:
>  I just found a simple, but nice, trick to make regexes less unlegible.
> Using substrings to represent sub-patterns. E.g. instead of:
[...]

Another option is to use the re.VERBOSE flag.  This allows you to put
comments in your regular expression and use whitespace for formatting.
 See this article for an example:

http://diveintopython.org/regular_expressions/verbose.html

HTH!

-- 
John.

From eike.welk at gmx.net  Fri Dec 12 00:11:49 2008
From: eike.welk at gmx.net (Eike Welk)
Date: Fri, 12 Dec 2008 00:11:49 +0100
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111336k42667f9bq4f8da9582cac4c43@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
	<36601b010812111336k42667f9bq4f8da9582cac4c43@mail.gmail.com>
Message-ID: <200812120011.49764.eike.welk@gmx.net>

On Thursday 11 December 2008, Ravi Kondamuru wrote:
> This was a great info exchange for me.
> I am going to try out the all-python solution and see how it works
> out. thank you all,

You could try to optimize slow parts with the compiled Cython 
language. Nearly all Python code is legal Cython; but if you declare 
variables as C datatypes operations with these variables will be fast 
like in C.
http://www.cython.org/
Introduction for C programmers:
http://docs.cython.org/docs/language_basics.html

The language is geared a bit towards numerical computations. However 
Python strings are automatically converted to 'char *', so it is 
useful for you. 

Cython is a fork of Pyrex, which can keep up fairly well with real C 
programs:
http://www.scipy.org/PerformancePython#head-a73fa06d3c4f3bda71b3526d30d51c492d8f80df

Kind regards,
Eike.

From lie.1296 at gmail.com  Fri Dec 12 01:08:43 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Fri, 12 Dec 2008 00:08:43 +0000 (UTC)
Subject: [Tutor] no attribute
References: <fbf64d2b0812111334t7a2b5ddep5182007a6e7cb47c@mail.gmail.com>
	<ghs2a5$75b$1@ger.gmane.org>
Message-ID: <ghsa2b$4dn$1@ger.gmane.org>

On Thu, 11 Dec 2008 21:56:19 +0000, Alan Gauld wrote:

> "Bryan Fodness" <bryan.fodness at gmail.com> wrote
> 
>>I am trying to change values in a file.  The following code does not
>>seem to
>> find the attribute.
>>
>> def anonymize(obj, attr):
>>    try:
>>        obj.attr = 'Anonymize'
>>    except AttributeError:
>>        pass
> 
> This code is looking for an attribute of obj called attr It is not using
> the name of attr stored in the attr parameter.
> 
> To do that you will need to use the setattr function.
> 
> HTH

I don't think you'll even need setattr (for the piece of code given), 
because anonymize receives a fixed string. If that code is part of more 
complex code where the string might be anything setattr might be needed 
though.

What are you trying to do though?


From zstumgoren at gmail.com  Fri Dec 12 01:23:34 2008
From: zstumgoren at gmail.com (Serdar Tumgoren)
Date: Thu, 11 Dec 2008 19:23:34 -0500
Subject: [Tutor] advice on regex matching for dates?
In-Reply-To: <5e58f2e40812111445v5b1c2f7ehe98cccf0c207c270@mail.gmail.com>
References: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>
	<4941967C.2010504@free.fr>
	<5e58f2e40812111445v5b1c2f7ehe98cccf0c207c270@mail.gmail.com>
Message-ID: <cadf44510812111623n10bc0830wff9842ec95b43c29@mail.gmail.com>

Thanks to all for the replies!

The FeedParser example is mind-bending (at least for this noob), but of
course looks very powerful.  And thanks for the tips on cleaning up the
appearance of the code with sup-patterns. Those regex's can get hairy pretty
fast.
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From denis.spir at free.fr  Thu Dec 11 19:58:31 2008
From: denis.spir at free.fr (spir)
Date: Thu, 11 Dec 2008 19:58:31 +0100
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
Message-ID: <494162D7.7080202@free.fr>

Ravi Kondamuru a ?crit :
> I am trying to read a binary log file to extract system counters. These
> counters will then be used to generate web-based graphs using the
> chart-director api in python. For extracting the counters I planning to
> write a program in C to read and give the output as lists for use by
> chart-director. If possible i would like to do the parsing of data only once
> in C on the log file and pass the processed output for direct use by
> python.
> I have thought about having to populate a database first but will prefer to
> avoid having another intermediate datastore (apart from the log file).
> 
> thanks,
> Ravi.
> 
> On Thu, Dec 11, 2008 at 10:27 AM, Steve Willoughby <steve at alchemy.com>wrote:
> 
>> Ravi Kondamuru wrote:
>>
>>> Hi,
>>> I am writing a script to read list output from a C executable. How should
>>> c program be written so that python can read the output as a list?
>>> Any pointers to info on this appreciated.
>>>
>> The possibilities are truly wide open on this.  Python can read a variety
>> of standard formats (and of course can have custom code to read anything.
>>  Depending on what the data involved actually are, you need to decide what
>> format works best.
>>
>> A simple approach is to have the C program write simple CSV output, and use
>> Python's csv module to read it.  A more complex solution might be to use
>> XML.  There are approximately 52,495,102 other possibilities available too,
>> so you have lots of room to work out what's best for your  application.
>>  More specific information on what you're trying to accomplish would help
>> narrow it down as well.

What type are these system counters? If you want to avoid reparsing in python, 
why not let C write a valid python literal, then simply import? (depends on 
what "huge" means for you). Assuming they are ints:
=========
counters.py:
counters = [
123,
456,
789,
...
]
=======
prog.py:
from counters import counters

denis


From bgailer at gmail.com  Fri Dec 12 04:54:22 2008
From: bgailer at gmail.com (bob gailer)
Date: Thu, 11 Dec 2008 22:54:22 -0500
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	<49415B8A.3080701@alchemy.com>	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>	<49415FDF.3080601@alchemy.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
Message-ID: <4941E06E.1090608@gmail.com>

Ravi Kondamuru wrote:
> Reasons for C:
> 1. The log files I am working are 60-100MB files. I *assumed* using C 
> will reduce the parse time.
> 2. The records themselves are variable length and hence was concerned 
> about the complexity for implementation in python.
> 3. Since I am not using a database, each request to refresh the graph 
> (changing time duration for display) will have to re-parse the file 
> all over again. And hence speed in parsing the log is important.

There should never be a need to reparse the same file. Please present 
the case more specifically.

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From Gang.Chen at nokia.com  Fri Dec 12 04:44:37 2008
From: Gang.Chen at nokia.com (Chen Gang (Nokia-D/Beijing))
Date: Fri, 12 Dec 2008 11:44:37 +0800
Subject: [Tutor] how to convert '\xf0' to 0xf0?
Message-ID: <1229053477.20204.0.camel@localhost.localdomain>



From steve at alchemy.com  Fri Dec 12 05:50:29 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Thu, 11 Dec 2008 20:50:29 -0800
Subject: [Tutor] how to convert '\xf0' to 0xf0?
In-Reply-To: <1229053477.20204.0.camel@localhost.localdomain>
References: <1229053477.20204.0.camel@localhost.localdomain>
Message-ID: <4941ED95.1020206@alchemy.com>

ord('\xf0')

From alan.gauld at btinternet.com  Fri Dec 12 10:01:22 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Fri, 12 Dec 2008 09:01:22 -0000
Subject: [Tutor] how to convert '\xf0' to 0xf0?
References: <1229053477.20204.0.camel@localhost.localdomain>
Message-ID: <ght994$3o5$1@ger.gmane.org>

What exactly do you want to achieve? I suspect its not what you asked!

To convert the character whose hex value of F0 to an integer value of 
F0
you can use ord() (or just reinterpret the character as a string
using the struct module).

>>> ord('\xf0')
240

To display the hex value of a character as a hex string you can use
string formatting or the hex() function:

>>> c = '\xF0'
>>> "0x%x" % ord(c)
'0xf0'
>>> "0x%X" % ord(c)
'0xF0'
>>> hex(ord(c))
'0xf0'

Remember that the representation of a number is always a string.
The value of a number is always binary and can be represented in
any base with the default in Python being decimal.

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld



From ravikondamuru at gmail.com  Fri Dec 12 12:13:16 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Fri, 12 Dec 2008 03:13:16 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <4941E06E.1090608@gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
	<49415FDF.3080601@alchemy.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
	<4941E06E.1090608@gmail.com>
Message-ID: <36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>

Denis, These are 32bit, 64bit counters (essentially numbers).
Bob, There are well over 10K counters in the log file that are updated every
5 secs. If a counter1's graph was requested, log will have to be parsed once
to get the data points. If a user asked for a counter2, now it needs to be
retrieved from the log file. Which essentially means having to go through
the logfile again. This is because i want to try to avoid using a database
to store values after parsing the file.
thanks,
Ravi.


On Thu, Dec 11, 2008 at 7:54 PM, bob gailer <bgailer at gmail.com> wrote:

> Ravi Kondamuru wrote:
>
>> Reasons for C:
>> 1. The log files I am working are 60-100MB files. I *assumed* using C will
>> reduce the parse time.
>> 2. The records themselves are variable length and hence was concerned
>> about the complexity for implementation in python.
>> 3. Since I am not using a database, each request to refresh the graph
>> (changing time duration for display) will have to re-parse the file all over
>> again. And hence speed in parsing the log is important.
>>
>
> There should never be a need to reparse the same file. Please present the
> case more specifically.
>
>
> --
> Bob Gailer
> Chapel Hill NC 919-636-4239
>
>
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From lie.1296 at gmail.com  Fri Dec 12 12:33:55 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Fri, 12 Dec 2008 11:33:55 +0000 (UTC)
Subject: [Tutor] reading output from a c executable.
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
	<49415FDF.3080601@alchemy.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
	<4941E06E.1090608@gmail.com>
	<36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
Message-ID: <ghti72$rf2$1@ger.gmane.org>

On Fri, 12 Dec 2008 03:13:16 -0800, Ravi Kondamuru wrote:

> Denis, These are 32bit, 64bit counters (essentially numbers). Bob, There
> are well over 10K counters in the log file that are updated every 5
> secs. If a counter1's graph was requested, log will have to be parsed
> once to get the data points. If a user asked for a counter2, now it
> needs to be retrieved from the log file. Which essentially means having
> to go through the logfile again. This is because i want to try to avoid
> using a database to store values after parsing the file. thanks,
> Ravi.

Instead of using a file, why not use pipes? Using pipes is surely much 
faster than reading from a file, and using pipes allow you to send log 
entries in "messages" which means you don't need to reparse the whole 
logfile on every update, just the parts that have changed.


From lie.1296 at gmail.com  Fri Dec 12 12:43:46 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Fri, 12 Dec 2008 11:43:46 +0000 (UTC)
Subject: [Tutor] advice on regex matching for dates?
References: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>
	<4941967C.2010504@free.fr>
Message-ID: <ghtip8$rf2$2@ger.gmane.org>

On Thu, 11 Dec 2008 23:38:52 +0100, spir wrote:

> Serdar Tumgoren a ?crit :
>> Hey everyone,
>> 
>> I was wondering if there is a way to use the datetime module to check
>> for variations on a month name when performing a regex match?
>> 
>> In the script below, I created a regex pattern that checks for dates in
>> the following pattern:  "August 31, 2007". If there's a match, I can
>> then print the capture date and the line from which it was extracted.
>> 
>> While it works in this isolated case, it struck me as not very
>> flexible. What happens when I inevitably get data that has dates
>> formatted in a different way? Do I have to create some type of library
>> that contains variations on each month name (i.e. - January, Jan., 01,
>> 1...) and use that to parse each line?
>> 
>> Or is there some way to use datetime to check for date patterns when
>> using regex? Is there a "best practice" in this area that I'm unaware
>> of in this area?
>> 
>> Apologies if this question has been answered elsewhere. I wasn't sure
>> how to research this topic (beyond standard datetime docs), but I'd be
>> happy to RTM if someone can point me to some resources.
>> 
>> Any suggestions are welcome (including optimizations of the code
>> below).
>> 
>> Regards,
>> Serdar
>> 
>> #!/usr/bin/env python
>> 
>> import re, sys
>> 
>> sourcefile = open(sys.argv[1],'r')
>> 
>> pattern =
>> re.compile(r'(?P<month>January|February|March|April|May|June|July|
August|September|October|November|December)\s(?P<day>\d{1,2}),\s(?P<year>
\d{4})')
>> 
>> pattern2 = re.compile(r'Return to List')
>> 
>> counter = 0
>> 
>> for line in sourcefile:
>>     x = pattern.search(line)
>>     break_point = pattern2.match(line)
>> 
>>     if x:
>>         counter +=1
>>         print "%s %d, %d <== %s" % ( x.group('month'),
>>         int(x.group('day')),
>> int(x.group('year')), line ),
>>     elif break_point:
>>         break
>> 
>> print counter
>> sourcefile.close()
> 
> I just found a simple, but nice, trick to make regexes less unlegible.
> Using substrings to represent sub-patterns. E.g. instead of:
> 
> p =
> re.compile(r'(?P<month>January|February|March|April|May|June|July|
August|September|October|November|December)\s(?P<day>\d{1,2}),\s(?P<year>
\d{4})')
> 
> write first:
> 
> month =
> r'(?P<month>January|February|March|April|May|June|July|August|September|
October|November|December)'
> day = r'(?P<day>\d{1,2})'
> year = r'(?P<year>\d{4})'
> 
> then:
> p = re.compile( r"%s\s%s,\s%s" % (month,day,year) ) or even:
> p = re.compile( r"%(month)s\s%(day)s,\s%(year)s" %
> {'month':month,'day':day,'year':year} )
> 

You might realize that that wouldn't help much and might even hide bugs 
(or make it harder to see). regex IS hairy in the first place. 

I'd vote for namespace in regex to allow a pattern inside a special pair 
tags to be completely ignorant of anything outside it. And also I'd vote 
for a compiled-pattern to be used as a subpattern. But then, with all 
those limbs, I might as well use a full-blown syntax parser instead.


From bgailer at gmail.com  Fri Dec 12 15:12:42 2008
From: bgailer at gmail.com (bob gailer)
Date: Fri, 12 Dec 2008 09:12:42 -0500
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	
	<49415B8A.3080701@alchemy.com>	
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>	
	<49415FDF.3080601@alchemy.com>	
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>	
	<4941E06E.1090608@gmail.com>
	<36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
Message-ID: <4942715A.2010202@gmail.com>

Ravi Kondamuru wrote:
> Denis, These are 32bit, 64bit counters (essentially numbers).
> Bob, There are well over 10K counters in the log file that are updated 
> every 5 secs. If a counter1's graph was requested, log will have to be 
> parsed once to get the data points. If a user asked for a counter2, 
> now it needs to be retrieved from the log file. Which essentially 
> means having to go through the logfile again. This is because i want 
> to try to avoid using a database to store values after parsing the file.

Thank you. When you said "same file" I did not realize that it meant 
"same name modified data"!

If the file is a mix of 32 and 64 bit numbers, how do you know the 
length of each counter?


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From bgailer at gmail.com  Fri Dec 12 15:30:11 2008
From: bgailer at gmail.com (bob gailer)
Date: Fri, 12 Dec 2008 09:30:11 -0500
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>	
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>	
	<49415B8A.3080701@alchemy.com>	
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>	
	<49415FDF.3080601@alchemy.com>	
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>	
	<4941E06E.1090608@gmail.com>
	<36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
Message-ID: <49427573.5020902@gmail.com>

Ravi Kondamuru wrote:
> Denis, These are 32bit, 64bit counters (essentially numbers).
> Bob, There are well over 10K counters in the log file that are updated 
> every 5 secs. If a counter1's graph was requested, log will have to be 
> parsed once to get the data points. If a user asked for a counter2, 
> now it needs to be retrieved from the log file. Which essentially 
> means having to go through the logfile again. This is because i want 
> to try to avoid using a database to store values after parsing the file.
Here is a little test program I wrote to check timing on a file of 
*100,000* 64 bit counters.

import time, struct
ctrs = 100000
s = time.time()
# create a file of 800,000 characters (100,000 64 bit numbers)
f = open('ravi.dat', 'wb')
for i in range(ctrs):
  f.write('abcdefgh') # it does not matter what we write as long as it 
is 8 bytes.
print time.time() - s

s = time.time()
l = []
# read the file
f = open('ravi.dat', 'rb').read()

# unpack each 8 characters into an integer and collect in a list
for b in range(0, ctrs, 8):
  n = struct.unpack('q', f[b:b+8])
  l.append(n)
print time.time() - s

Writing the file took 0.14 seconds on my computer
Reading and unpacking 0.04 seconds.
I think you can set performance issues aside.

There is a principle in programming that proposes:
1 - get a program running. Preferably in Python as development time is 
much faster.
2 - check its performance.
3 - refine as needed.

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From denis.spir at free.fr  Fri Dec 12 17:40:39 2008
From: denis.spir at free.fr (spir)
Date: Fri, 12 Dec 2008 17:40:39 +0100
Subject: [Tutor] regex sub/super patterns ( was:advice on regex matching
 for dates?)
In-Reply-To: <ghtip8$rf2$2@ger.gmane.org>
References: <cadf44510812111131t3674327ci57a2f90af7671593@mail.gmail.com>	<4941967C.2010504@free.fr>
	<ghtip8$rf2$2@ger.gmane.org>
Message-ID: <49429407.6040802@free.fr>

Lie Ryan a ?crit :

 >> I just found a simple, but nice, trick to make regexes less unlegible.
 >> Using substrings to represent sub-patterns. E.g. instead of:
 >>
 >> p =
 >> re.compile(r'(?P<month>January|February|March|April|May|June|July|
 > August|September|October|November|December)\s(?P<day>\d{1,2}),\s(?P<year>
 > \d{4})')
 >> write first:
 >>
 >> month =
 >> r'(?P<month>January|February|March|April|May|June|July|August|September|
 > October|November|December)'
 >> day = r'(?P<day>\d{1,2})'
 >> year = r'(?P<year>\d{4})'
 >>
 >> then:
 >> p = re.compile( r"%s\s%s,\s%s" % (month,day,year) ) or even:
 >> p = re.compile( r"%(month)s\s%(day)s,\s%(year)s" %
 >> {'month':month,'day':day,'year':year} )
 >>
 >
 > You might realize that that wouldn't help much and might even hide bugs
 > (or make it harder to see). regex IS hairy in the first place.
 >
 > I'd vote for namespace in regex to allow a pattern inside a special pair
 > tags to be completely ignorant of anything outside it. And also I'd vote
 > for a compiled-pattern to be used as a subpattern. But then, with all
 > those limbs, I might as well use a full-blown syntax parser instead.

Just tried to implement something like that for fun. The trick I chose is to 
reuse the {} in pattern strings, as (as far as I know) the curly braces are 
used only for repetition; hence there should be not conflict. A format would 
then look like that:

	format = r"...{subpatname}...{subpatname}..."

For instance:

	format = r"record: {num}{n} -- name:{id}"

(Look at the code below.)

Found 2 issues:
-1- Regex patterns haven't any 'string' attribute to recover the string they 
have beeen built from. As they aren't python objects, we cannot set anything on 
them. So that we need to play with strings directly. (Which means that, once 
the sub-pattern tested, we must copy its string.)
-2- There must be a scope to look for subpattern strings per name. the only 
practicle solution I could think at is to make super-patterns ,of full 
grammars, instances of a class that copes with the details. Subpattern strings 
have to be attrs of this object.

_______________________________________________
from re import compile as pattern
class Grammar(object):
	identifier = "[a-zA-Z_][a-zA-Z_0-9]*"
	sub_pattern = pattern("\{%s\}" % identifier)
	def subString(self,result):
		name = result.group()[1:-1]
		try:
			return self.__dict__[name]
		except KeyError:
			raise AttributeError("Cannot find sub-pattern string '%s'."	% name)
	def makePattern(self, format=None):
		format = self.format if format is None else format
		self.pattern_string = Grammar.sub_pattern.sub(self.subString,format)
		print "%s -->\n%s" % (self.format,self.pattern_string)
		self.pattern = pattern(self.pattern_string)
		return self.pattern

if __name__ == "__main__":
	record = Grammar()
	record.num	= r"n[?\.oO]\ ?"
	record.n 	= r"[0-9]+"
	record.id 	= r"[a-zA-Z_][a-zA-Z_0-9]*"
	record.format = r"record: {num}{n} -- name:{id}"
	record.makePattern()
	text = """
	record: no 123 -- name:blah
	record: n.456 -- name:foo
	record: n?789 -- name:foo_bar
	"""
	result = record.pattern.findall(text)
	print result,'\n'
	# with format attr and invalid format
	bloo_format = r"record: {num}{n} -- name:{id}{bloo_bar}"
	record.makePattern(bloo_format)
	result = record.pattern.findall(text)
	print result



From technorapture at gmail.com  Sat Dec 13 00:06:35 2008
From: technorapture at gmail.com (Shrutarshi Basu)
Date: Fri, 12 Dec 2008 18:06:35 -0500
Subject: [Tutor] Ask a class for it's methods
Message-ID: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>

I have a list containing strings like :

func1[]
func2[1,2]
func3[blah]

I want to turn them into method calls (with numeric or string
arguments) on a supplied object. I'm trying to figure out the best way
to do this. Since these lists could be very big, and the methods could
be rather complex (mainly graphics manipulation) I would like to start
by getting a list of the object's methods and make sure that all the
strings are valid. Is there a way to ask an object for a list of it's
methods (with argument requirements if possible)?
The next question is once I've validated the list, what's the easiest
way to turn the list element into a method call? I'll be parsing the
string to separate out the method name and arguments. If I store the
method name (say func1)  in a variable, say var, could I do
object.var() and have if call the func1 method in object?
Thanks for your help and I'll surely have more questions as I get along,
Thanks
Basu

-- 
The ByteBaker :
http://www.bytebaker.com

From alan.gauld at btinternet.com  Sat Dec 13 00:41:38 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Fri, 12 Dec 2008 23:41:38 -0000
Subject: [Tutor] Ask a class for it's methods
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
Message-ID: <ghusrk$bij$1@ger.gmane.org>


"Shrutarshi Basu" <technorapture at gmail.com> wrote

>I have a list containing strings like :
>
> func1[]
> func2[1,2]
> func3[blah]
>
> I want to turn them into method calls (with numeric or string
> arguments) on a supplied object.

The easiest way is to call getattr() which will return a reference
to the method if it exists.

> be rather complex (mainly graphics manipulation) I would like to 
> start
> by getting a list of the object's methods and make sure that all the
> strings are valid.

Why not just handle it using try/except?
Thats exactly what exceptions were designed for.

> Is there a way to ask an object for a list of it's
> methods (with argument requirements if possible)?

You can try dir() but that won't give you the parameters.
But again try/except can catch an invalid call and you can detect
whether the number of parameters is wrong in the except clause.

> method name (say func1)  in a variable, say var, could I do
> object.var() and have if call the func1 method in object?

no, but you can do this:

>>> class C:
...     def f(self, x): print x
...
>>> c = C()
>>> dir(c)
['__doc__', '__module__', 'f']
>>> m = getattr(c,'f')
>>> m(42)
42
>>> try: m(43,'foo')
... except TypeError:
...     # parse the error message here
...     print 'Method of', c, 'takes ??? arguments'
...
Method of <__main__.C instance at 0x01BF8350> takes ??? arguments
>>>

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From technorapture at gmail.com  Sat Dec 13 02:05:23 2008
From: technorapture at gmail.com (Shrutarshi Basu)
Date: Fri, 12 Dec 2008 20:05:23 -0500
Subject: [Tutor] Ask a class for it's methods
In-Reply-To: <ghusrk$bij$1@ger.gmane.org>
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
	<ghusrk$bij$1@ger.gmane.org>
Message-ID: <376fbdcf0812121705h5b554feei49304551bc1f482c@mail.gmail.com>

I normally would use exceptions, because I think exceptions are a
great idea. But since the functions may be time-consuming graphics
functions and the lists could easily be hundreds of such calls, I
don't want the user to sit around for something that might fail. Of
course, I'm just starting so my assumptions about time might not turn
out to be valid, so I could just use exceptions in the end. This is an
option I'm exploring.

Getattr and dir seem to be the way to go for now, so I'll be trying to
apply them over the weekend and see how it turns out. Any more ideas
welcome.
Thanks,
Basu

-- 
The ByteBaker :
http://www.bytebaker.com

From lie.1296 at gmail.com  Sat Dec 13 02:48:52 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sat, 13 Dec 2008 01:48:52 +0000 (UTC)
Subject: [Tutor] Ask a class for it's methods
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
	<ghusrk$bij$1@ger.gmane.org>
	<376fbdcf0812121705h5b554feei49304551bc1f482c@mail.gmail.com>
Message-ID: <ghv4a4$8th$6@ger.gmane.org>

On Fri, 12 Dec 2008 20:05:23 -0500, Shrutarshi Basu wrote:

> I normally would use exceptions, because I think exceptions are a great
> idea. But since the functions may be time-consuming graphics functions
> and the lists could easily be hundreds of such calls, I don't want the
> user to sit around for something that might fail. Of course, I'm just
> starting so my assumptions about time might not turn out to be valid, so
> I could just use exceptions in the end. This is an option I'm exploring.

The general rule of thumb is usually that exception is slow on the 
exceptional cases arise, while being faster if the try block doesn't 
fail. On the other hand, using if-block is usually slow all over, but not 
as slow as exception's exceptional cases.


From andreas at kostyrka.org  Sat Dec 13 02:59:34 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Sat, 13 Dec 2008 02:59:34 +0100
Subject: [Tutor] Ask a class for it's methods
In-Reply-To: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
Message-ID: <20081213015933.GA27333@hell.kostyrka.org>

On Fri, Dec 12, 2008 at 06:06:35PM -0500, Shrutarshi Basu wrote:
> I have a list containing strings like :
> 
> func1[]
> func2[1,2]
> func3[blah]
> 
> I want to turn them into method calls (with numeric or string
> arguments) on a supplied object. I'm trying to figure out the best way
> to do this. Since these lists could be very big, and the methods could
> be rather complex (mainly graphics manipulation) I would like to start
> by getting a list of the object's methods and make sure that all the
> strings are valid. Is there a way to ask an object for a list of it's
> methods (with argument requirements if possible)?

Well, there are ways, but they are not reliable by design. Objects can return dynamically
methods.

So use something like this:

if callable(getattr(obj, "func1")):
    # func1 exists.

Guess nowaday with Python3 released, you should not use callable, but instead
test on __call__

if hasattr(getattr(obj, "func1"), "__call__"):



> The next question is once I've validated the list, what's the easiest
> way to turn the list element into a method call? I'll be parsing the
> string to separate out the method name and arguments. If I store the
> method name (say func1)  in a variable, say var, could I do
> object.var() and have if call the func1 method in object?
getattr(object, var)() # calls the method named in var:

class A:
    def x(self, a, b):
        return a + b

instance = A()

name = "x"

args_positional = (1, 2)

print getattr(instance, name)(*args_positional) # prints 3

args_by_name = dict(a=1, b=2)

print getattr(instance, name)(**args_by_name) # prints 3 too.

Andreas

From lie.1296 at gmail.com  Sat Dec 13 09:03:10 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sat, 13 Dec 2008 08:03:10 +0000 (UTC)
Subject: [Tutor] Ask a class for it's methods
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
	<20081213015933.GA27333@hell.kostyrka.org>
Message-ID: <ghvq7u$qq0$2@ger.gmane.org>

On Sat, 13 Dec 2008 02:59:34 +0100, Andreas Kostyrka wrote:

> On Fri, Dec 12, 2008 at 06:06:35PM -0500, Shrutarshi Basu wrote:
>> I have a list containing strings like :
>> 
>> func1[]
>> func2[1,2]
>> func3[blah]
>> 
>> I want to turn them into method calls (with numeric or string
>> arguments) on a supplied object. I'm trying to figure out the best way
>> to do this. Since these lists could be very big, and the methods could
>> be rather complex (mainly graphics manipulation) I would like to start
>> by getting a list of the object's methods and make sure that all the
>> strings are valid. Is there a way to ask an object for a list of it's
>> methods (with argument requirements if possible)?
>
> Well, there are ways, but they are not reliable by design. Objects can
> return dynamically methods.
> 
> So use something like this:
> 
> if callable(getattr(obj, "func1")):
>     # func1 exists.
> 
> Guess nowaday with Python3 released, you should not use callable, but
> instead test on __call__
> 
> if hasattr(getattr(obj, "func1"), "__call__"):

or the more pythonic version would just call func() and catch exception 
if it's not callable:

try:
    func1()
except TypeError:
    print "func1 is not callable"


From andreas at kostyrka.org  Sat Dec 13 10:19:34 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Sat, 13 Dec 2008 10:19:34 +0100
Subject: [Tutor] Ask a class for it's methods
In-Reply-To: <ghvq7u$qq0$2@ger.gmane.org>
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
	<20081213015933.GA27333@hell.kostyrka.org>
	<ghvq7u$qq0$2@ger.gmane.org>
Message-ID: <20081213091934.GA28026@hell.kostyrka.org>

On Sat, Dec 13, 2008 at 08:03:10AM +0000, Lie Ryan wrote:
> On Sat, 13 Dec 2008 02:59:34 +0100, Andreas Kostyrka wrote:
> 
> > On Fri, Dec 12, 2008 at 06:06:35PM -0500, Shrutarshi Basu wrote:
> >> I have a list containing strings like :
> >> 
> >> func1[]
> >> func2[1,2]
> >> func3[blah]
> >> 
> >> I want to turn them into method calls (with numeric or string
> >> arguments) on a supplied object. I'm trying to figure out the best way
> >> to do this. Since these lists could be very big, and the methods could
> >> be rather complex (mainly graphics manipulation) I would like to start
> >> by getting a list of the object's methods and make sure that all the
> >> strings are valid. Is there a way to ask an object for a list of it's
> >> methods (with argument requirements if possible)?
> >
> > Well, there are ways, but they are not reliable by design. Objects can
> > return dynamically methods.
> > 
> > So use something like this:
> > 
> > if callable(getattr(obj, "func1")):
> >     # func1 exists.
> > 
> > Guess nowaday with Python3 released, you should not use callable, but
> > instead test on __call__
> > 
> > if hasattr(getattr(obj, "func1"), "__call__"):
> 
> or the more pythonic version would just call func() and catch exception 
> if it's not callable:
> 
> try:
>     func1()
> except TypeError:
>     print "func1 is not callable"

But it happens to be wrong :)

Consider:

def func1():
    raise TypeError("except does not care where in the callstack the exception happens!!!")

Common sources, IMHE, for TypeErrors include int(not_a_string_or_number), which raises a TypeError.

Andreas

From btkuhn at email.unc.edu  Sat Dec 13 15:52:44 2008
From: btkuhn at email.unc.edu (btkuhn at email.unc.edu)
Date: Sat, 13 Dec 2008 09:52:44 -0500
Subject: [Tutor] Working with lists
Message-ID: <20081213095244.n4clmwk3k4gkgk04@webmail4.isis.unc.edu>

Hi everyone,

I seem to use this pattern alot when writing functions and I'm 
wondering if there is a more efficient method. It comes up whenever I 
want to work with more than one item in a list; for instance, say I 
want to add each consecutive number in alist and output the new list. 
Ideally, I'd be able to write:

for num in list1:
newlist.append(num+nextnum)

This doesn't work, though because there's no way to access "nextnum" 
unless I implement a "count" variable like this:

count=1
for num in list1:
newlist.append(num+list1[count])
count+=1

Instead, it usually ends up easier to write:

for index in range (len(list1)-1):
newlist.append((list1[index]+list1[index+1]))

It's not a big deal to have to write the additional code, but problems 
arise when I use this structure in the context of more complex 
functions, when I am passing multiple lists of varying length, because 
it is easy to get confused with the index numbers and I can't do 
anything to the last value of the list, since I then get an 
"indexerror" because the function tries to call "list[i+1]".

Is there a simpler way to do a procedure like this?

Thanks.

From roadierich at googlemail.com  Sat Dec 13 17:49:20 2008
From: roadierich at googlemail.com (Richard Lovely)
Date: Sat, 13 Dec 2008 16:49:20 +0000
Subject: [Tutor] Working with lists
In-Reply-To: <20081213095244.n4clmwk3k4gkgk04@webmail4.isis.unc.edu>
References: <20081213095244.n4clmwk3k4gkgk04@webmail4.isis.unc.edu>
Message-ID: <f0b4202b0812130849n6fe330eflf1ffc11561d280a5@mail.gmail.com>

When you need indexes for a list you're iterating over, you want to
look at the function enumerate(), which returns an iterator yielding
(key, value) tuples.

If you're working with multiple lists, itertools.imap and
itertools.imap_longest are handy if you want to keep the lists in
lockstep:

>>> l1 = [1,2,3,4,5]
>>> l2 = ['a','b','c','d','e','f']
>>> for key, value in enumerate(l1):
>>>     print key, value
0 1
1 2
2 3
3 4
4 5
>>> import itertools
>>> for i1, i2 in itertools.izip(l1, l2):
>>>     print i1, i2
1 'a'
2 'b'
3 'c'
4 'd'
5 'e'
>>> for i1, i2 in intertools.izip_longest(l1, l2, fillvalue=0):
>>>     print i1, i2
1 'a'
2 'b'
3 'c'
4 'd'
5 'e'
0 'f'

Preventing yourself from using invalid indexes is harder, and depends
on exactly what you want to happen to the last value in the source
list.  To skip that last value, you could use something like the
following:
if value == longest_list[-1]:
    break

using -1 as an index will always return the last value of that list.
Passing a unique value to fillvalue on izip_longest is another way.  I
normally use a specially created class:

class EndOfList(object):
    pass

then you do:
for values in izip_longest(l1, l2... fillvalue=EndOfList)
    if EndOfList in values: # one of the lists has run out of values
        # do something special, then
        break

And another way of doing your first example, that's one of the
extremly useful tools in python's armoury:

newlist = [a+b for a,b in itertools.izip(l1[:-1], l1[1:])]
This is a list comprehension, and is a very useful tool when you want
to build a list from another list (or any other iterable).  The
'slices' each give you a list with one less item, the first missing
the last item, the second, the first item.

Hope there's the information somewhere in this somewhat jumbled
response to help you.


Richard "Roadie Rich" Lovely, part of the JNP|UK Famile
www.theJNP.com



2008/12/13  <btkuhn at email.unc.edu>:
> Hi everyone,
>
> I seem to use this pattern alot when writing functions and I'm wondering if
> there is a more efficient method. It comes up whenever I want to work with
> more than one item in a list; for instance, say I want to add each
> consecutive number in alist and output the new list. Ideally, I'd be able to
> write:
>
> for num in list1:
> newlist.append(num+nextnum)
>
> This doesn't work, though because there's no way to access "nextnum" unless
> I implement a "count" variable like this:
>
> count=1
> for num in list1:
> newlist.append(num+list1[count])
> count+=1
>
> Instead, it usually ends up easier to write:
>
> for index in range (len(list1)-1):
> newlist.append((list1[index]+list1[index+1]))
>
> It's not a big deal to have to write the additional code, but problems arise
> when I use this structure in the context of more complex functions, when I
> am passing multiple lists of varying length, because it is easy to get
> confused with the index numbers and I can't do anything to the last value of
> the list, since I then get an "indexerror" because the function tries to
> call "list[i+1]".
>
> Is there a simpler way to do a procedure like this?
>
> Thanks.
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

From alan.gauld at btinternet.com  Sat Dec 13 19:19:00 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sat, 13 Dec 2008 18:19:00 -0000
Subject: [Tutor] Working with lists
References: <20081213095244.n4clmwk3k4gkgk04@webmail4.isis.unc.edu>
Message-ID: <gi0uam$su9$1@ger.gmane.org>


<btkuhn at email.unc.edu> wrote

> Ideally, I'd be able to write:
>
> for num in list1:
> newlist.append(num+nextnum)
>
> This doesn't work, though because there's no way to access "nextnum" 
> unless I implement a "count" variable like this:

Or use an iterator:

>>> L = [1,2,3,4,5,6]
>>> i = iter(L)
>>> L2 = [n+i.next() for n in i]
>>> L2
[3, 7, 11]

Is that what you want?


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From lie.1296 at gmail.com  Sun Dec 14 03:35:35 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Sun, 14 Dec 2008 02:35:35 +0000 (UTC)
Subject: [Tutor] Ask a class for it's methods
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
	<20081213015933.GA27333@hell.kostyrka.org> <ghvq7u$qq0$2@ger.gmane.org>
	<20081213091934.GA28026@hell.kostyrka.org>
Message-ID: <gi1rdn$vrd$1@ger.gmane.org>

On Sat, 13 Dec 2008 10:19:34 +0100, Andreas Kostyrka wrote:

> On Sat, Dec 13, 2008 at 08:03:10AM +0000, Lie Ryan wrote:
>> On Sat, 13 Dec 2008 02:59:34 +0100, Andreas Kostyrka wrote:
>> 
>> > On Fri, Dec 12, 2008 at 06:06:35PM -0500, Shrutarshi Basu wrote:
>> >> I have a list containing strings like :
>> >> 
>> >> func1[]
>> >> func2[1,2]
>> >> func3[blah]
>> >> 
>> >> I want to turn them into method calls (with numeric or string
>> >> arguments) on a supplied object. I'm trying to figure out the best
>> >> way to do this. Since these lists could be very big, and the methods
>> >> could be rather complex (mainly graphics manipulation) I would like
>> >> to start by getting a list of the object's methods and make sure
>> >> that all the strings are valid. Is there a way to ask an object for
>> >> a list of it's methods (with argument requirements if possible)?
>> >
>> > Well, there are ways, but they are not reliable by design. Objects
>> > can return dynamically methods.
>> > 
>> > So use something like this:
>> > 
>> > if callable(getattr(obj, "func1")):
>> >     # func1 exists.
>> > 
>> > Guess nowaday with Python3 released, you should not use callable, but
>> > instead test on __call__
>> > 
>> > if hasattr(getattr(obj, "func1"), "__call__"):
>> 
>> or the more pythonic version would just call func() and catch exception
>> if it's not callable:
>> 
>> try:
>>     func1()
>> except TypeError:
>>     print "func1 is not callable"
> 
> But it happens to be wrong :)
> 
> Consider:
> 
> def func1():
>     raise TypeError("except does not care where in the callstack the
>     exception happens!!!")
> 
> Common sources, IMHE, for TypeErrors include
> int(not_a_string_or_number), which raises a TypeError.

Then it's the lower function's fault (i.e. bug) for not handling that 
exception, and if you really need it, it's trivial to check the "kind" of 
TypeError reraising the exception if it's not what we expect.

try:
    func1()
except TypeError, e:
    if not e.message.endswith('object is not callable'): 
        print 'There is something deeply wrong in your func1'
        raise
    print "func1 is not callable"


From metolone+gmane at gmail.com  Sun Dec 14 05:40:44 2008
From: metolone+gmane at gmail.com (Mark Tolonen)
Date: Sat, 13 Dec 2008 20:40:44 -0800
Subject: [Tutor] Working with lists
References: <20081213095244.n4clmwk3k4gkgk04@webmail4.isis.unc.edu>
Message-ID: <gi22oa$h15$1@ger.gmane.org>


<btkuhn at email.unc.edu> wrote in message 
news:20081213095244.n4clmwk3k4gkgk04 at webmail4.isis.unc.edu...
> Hi everyone,
>
> I seem to use this pattern alot when writing functions and I'm wondering 
> if there is a more efficient method. It comes up whenever I want to work 
> with more than one item in a list; for instance, say I want to add each 
> consecutive number in alist and output the new list. Ideally, I'd be able 
> to write:
>
> for num in list1:
> newlist.append(num+nextnum)
>
> This doesn't work, though because there's no way to access "nextnum" 
> unless I implement a "count" variable like this:
>
> count=1
> for num in list1:
> newlist.append(num+list1[count])
> count+=1
>
> Instead, it usually ends up easier to write:
>
> for index in range (len(list1)-1):
> newlist.append((list1[index]+list1[index+1]))
>
> It's not a big deal to have to write the additional code, but problems 
> arise when I use this structure in the context of more complex functions, 
> when I am passing multiple lists of varying length, because it is easy to 
> get confused with the index numbers and I can't do anything to the last 
> value of the list, since I then get an "indexerror" because the function 
> tries to call "list[i+1]".
>
> Is there a simpler way to do a procedure like this?

>From your description, do you want:

L = [1,2,3,4,5,6]   result = [3,5,6,9,11]?

I don't see anything in itertools, but this works:

>>> def ishift(L,n):
...         for i in xrange(len(L)-n+1):
...             yield L[i:i+n]
...
>>> for n in shift(L,2):
...         print n
...
[1, 2]
[2, 3]
[3, 4]
[4, 5]
[5, 6]
>>> for a,b,c in shift(L,3):
...         print a,b,c
...
1 2 3
2 3 4
3 4 5
4 5 6
>>> [sum(n) for n in ishift(L,2)]
[3, 5, 7, 9, 11]
>>> [sum(n) for n in ishift(L,3)]
[6, 9, 12, 15]

-Mark



From david at hlacik.eu  Sun Dec 14 13:38:31 2008
From: david at hlacik.eu (=?ISO-8859-2?Q?David_Hl=E1=E8ik?=)
Date: Sun, 14 Dec 2008 13:38:31 +0100
Subject: [Tutor] stable algorithm
Message-ID: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com>

Hi guys,

i am really sorry for making offtopic, hope you will not kill me, but
this is for me life important problem which needs to be solved within
next 12 hours..

I have to create stable algorithm for sorting n numbers from interval
[1,n^2] with time complexity O(n) .

Can someone please give me a hint. Would be very very thankful!

Thanks in advance!
D.

From ajoaugustine at gmail.com  Sun Dec 14 13:39:35 2008
From: ajoaugustine at gmail.com (Ajo Augustine)
Date: Sun, 14 Dec 2008 18:09:35 +0530
Subject: [Tutor] reading inputs from keyboard
Message-ID: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>

hi all;
can u let me know how  to  read an input string  from the keyboard?

-- 
Ajo
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From bgailer at gmail.com  Sun Dec 14 15:00:26 2008
From: bgailer at gmail.com (bob gailer)
Date: Sun, 14 Dec 2008 09:00:26 -0500
Subject: [Tutor] reading inputs from keyboard
In-Reply-To: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
References: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
Message-ID: <4945117A.1000500@gmail.com>

Ajo Augustine wrote:
> hi all;
> can u let me know how  to  read an input string  from the keyboard?

In Python 2.6 and lower:

raw_input(prompt)

Example program:

name = raw_input("Enter your name:")
print "Hello", name
raw_input("Press any key to exit.")

In Python 3

Example program:

name = input("Enter your name:")
print ("Hello", name)
input("Press any key to exit.")

The purpose of the last line - when you run the program by 
double-clicking or equivalent this keeps the window open so you can see 
the results.

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From ptmcg at austin.rr.com  Sun Dec 14 15:46:17 2008
From: ptmcg at austin.rr.com (Paul McGuire)
Date: Sun, 14 Dec 2008 08:46:17 -0600
Subject: [Tutor] Working with lists
In-Reply-To: <mailman.53.1229252420.31374.tutor@python.org>
References: <mailman.53.1229252420.31374.tutor@python.org>
Message-ID: <3E0E214CD0DB42FDA20AEDE2265C51EE@AWA2>

Even simpler than Rich Lovely's:

    newlist = [a+b for a,b in itertools.izip(l1[:-1], l1[1:])]
 
is to just use the built-in zip:

    newlist = [a+b for a,b in zip(l1[:-1], l1[1:])]

since you can be sure that l1[:-1] and l1[1:] will always be the same
length, so there is no need for a fill value (one of the enhancements you
get when using itertools.izip).

I often use zip this way when I need to get each item and its next-highest
neighbor from a list.

-- Paul



From btkuhn at email.unc.edu  Sun Dec 14 15:49:46 2008
From: btkuhn at email.unc.edu (btkuhn at email.unc.edu)
Date: Sun, 14 Dec 2008 09:49:46 -0500
Subject: [Tutor] Python Lib Files
Message-ID: <20081214094946.4k7u890c8wgw0okc@webmail4.isis.unc.edu>

Hello everyone,

I discovered yesterday that the Python package has a number of built in 
example scripts in the /lib directory. Perhaps this is common knowledge 
but I did not know about it. I can't seem to find any kind of guide to 
the files, though. Is there a readme somewhere that someone can point 
me to, or perhaps documentation for the files online? I cant find 
anything on the python.org site. This is for version 2.5.

Thanks very much,
Ben

From alan.gauld at btinternet.com  Sun Dec 14 15:57:34 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sun, 14 Dec 2008 14:57:34 -0000
Subject: [Tutor] stable algorithm
References: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com>
Message-ID: <gi36t2$nd$1@ger.gmane.org>

"David Hl?cik" <david at hlacik.eu> wrote

> this is for me life important problem which needs to be solved 
> within
> next 12 hours..

Does that mean its homework?

If so we can only offer pointers, but you need to tell us what
you have done yourself first.

If its not homework then please give a bit more background.
What exactly are you doing that needs this sort? - can you avoid
sorting in the first place, for example? What are the volumes?
Why is it time critical?

> I have to create stable algorithm for sorting n numbers from 
> interval
> [1,n^2] with time complexity O(n) .

Where have you looked for algorithms?
Which ones have you considered? Why were they unsuitable?

Or when you say "create" do you literally mean you have to
invent a brand new algorithm? That seems a bit of a harsh
demand in just 12 hours?

> Can someone please give me a hint. Would be very very thankful!

Google/Wikipedia would be good places to start.
Then try the Python documentation on sorting.

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Sun Dec 14 16:01:03 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sun, 14 Dec 2008 15:01:03 -0000
Subject: [Tutor] reading inputs from keyboard
References: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
Message-ID: <gi373j$1dl$1@ger.gmane.org>


"Ajo Augustine" <ajoaugustine at gmail.com> wrote 

> can u let me know how  to  read an input string  from the keyboard?

If you need to ask that then you need to work through any of the 
many Python tutorials. They all cover this, usually fairly early in 
the course.

Try some of those listed here:

http://wiki.python.org/moin/BeginnersGuide/NonProgrammers

or here

http://wiki.python.org/moin/BeginnersGuide/Programmers

depending on your past experience.

If you have questions come back here and we will try to 
answer them or point you to the answer.

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


From david at hlacik.eu  Sun Dec 14 17:08:24 2008
From: david at hlacik.eu (=?ISO-8859-2?Q?David_Hl=E1=E8ik?=)
Date: Sun, 14 Dec 2008 17:08:24 +0100
Subject: [Tutor] stable algorithm
In-Reply-To: <gi36t2$nd$1@ger.gmane.org>
References: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com>
	<gi36t2$nd$1@ger.gmane.org>
Message-ID: <cba415ca0812140808w68ef1c64ia0c8fd17181c0eb@mail.gmail.com>

>
> Does that mean its homework?
>
Hi,

yes it is homework , this is result :

#! /usr/bin/python
def sort(numbers):
        "sort n positive integers in O(n) provided that they are all < n^2"
        N = len(numbers) # get size of test numbers

        buckets_mod = [[] for i in xrange(N)]
        buckets_sorted = [[] for i in xrange(N+1)]

        # group numbers to buckets (list of numbers) with common modulus
        for n in numbers:
                buckets_mod[n % N].append(n)
        print "buckets_mod: %s" % buckets_mod

        # check numbers in buckets
        for l in buckets_mod:
                for n in l:
                        # place number into bucket number grouped by
result of division
                        buckets_sorted[n / N].append(n)
        print "buckets_sorted: %s" % buckets_sorted

        # search through sorted buckets and return list of sorted numbers
        return [n for l in buckets_sorted for n in l]

Hope it is optimal and OK, what you guys thinks?

Thanks in advance!

From david at hlacik.eu  Sun Dec 14 17:09:28 2008
From: david at hlacik.eu (=?ISO-8859-2?Q?David_Hl=E1=E8ik?=)
Date: Sun, 14 Dec 2008 17:09:28 +0100
Subject: [Tutor] stable algorithm
In-Reply-To: <cba415ca0812140808w68ef1c64ia0c8fd17181c0eb@mail.gmail.com>
References: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com>
	<gi36t2$nd$1@ger.gmane.org>
	<cba415ca0812140808w68ef1c64ia0c8fd17181c0eb@mail.gmail.com>
Message-ID: <cba415ca0812140809t5e46c3n91a500d24f40c55@mail.gmail.com>

> def sort(numbers):
>        "sort n positive integers in O(n) provided that they are all < n^2"

Sorry about wrong comment, should be range from [1 to n^2] not only < n^2.

D.

From bgailer at gmail.com  Sun Dec 14 17:16:08 2008
From: bgailer at gmail.com (bob gailer)
Date: Sun, 14 Dec 2008 11:16:08 -0500
Subject: [Tutor] Working with lists
In-Reply-To: <3E0E214CD0DB42FDA20AEDE2265C51EE@AWA2>
References: <mailman.53.1229252420.31374.tutor@python.org>
	<3E0E214CD0DB42FDA20AEDE2265C51EE@AWA2>
Message-ID: <49453148.1020600@gmail.com>

Paul McGuire wrote:
> Even simpler than Rich Lovely's:
>
>     newlist = [a+b for a,b in itertools.izip(l1[:-1], l1[1:])]
>  
> is to just use the built-in zip:
>
>     newlist = [a+b for a,b in zip(l1[:-1], l1[1:])]
>   
And then there's good old reduce which sadly is going to be harder to 
access in Python 3:

v = [1,2,3,4]
m = []
reduce(lambda x,y,m=m: (m.append(x+y), y)[1], v)
print m # [3, 5, 7]

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From alan.gauld at btinternet.com  Sun Dec 14 17:58:45 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sun, 14 Dec 2008 16:58:45 -0000
Subject: [Tutor] stable algorithm
References: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com><gi36t2$nd$1@ger.gmane.org>
	<cba415ca0812140808w68ef1c64ia0c8fd17181c0eb@mail.gmail.com>
Message-ID: <gi3e09$ksp$1@ger.gmane.org>

"David Hl?cik" <david at hlacik.eu> wrote

> yes it is homework , this is result :
>
> #! /usr/bin/python
> def sort(numbers):
>        "sort n positive integers in O(n) provided that they are all 
> < n^2"
>        N = len(numbers) # get size of test numbers
>
>        buckets_mod = [[] for i in xrange(N)]
>        buckets_sorted = [[] for i in xrange(N+1)]
>
>        # group numbers to buckets (list of numbers) with common 
> modulus
>        for n in numbers:
>                buckets_mod[n % N].append(n)
>        print "buckets_mod: %s" % buckets_mod

It would be interesting to see if using a dictionasry aws a sparce
array was any faster - it would save the initialisation step and
reduce the number of accesses of empty lists.

>        # check numbers in buckets
>        for l in buckets_mod:
>                for n in l:
>                        buckets_sorted[n / N].append(n)
>        print "buckets_sorted: %s" % buckets_sorted
>
>        # search through sorted buckets and return list of sorted 
> numbers
>        return [n for l in buckets_sorted for n in l]
>
> Hope it is optimal and OK, what you guys thinks?

Its almost certainly not optimal but from some basic testing it seems 
to
work and is linear as far as I can see (albeit with 5 loops over N).

Alan G 



From bermanrl at embarqmail.com  Sun Dec 14 18:21:59 2008
From: bermanrl at embarqmail.com (Robert Berman)
Date: Sun, 14 Dec 2008 12:21:59 -0500
Subject: [Tutor] reading inputs from keyboard
In-Reply-To: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
References: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
Message-ID: <494540B7.7000609@embarqmail.com>

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From david at hlacik.eu  Sun Dec 14 18:23:56 2008
From: david at hlacik.eu (=?ISO-8859-2?Q?David_Hl=E1=E8ik?=)
Date: Sun, 14 Dec 2008 18:23:56 +0100
Subject: [Tutor] stable algorithm
In-Reply-To: <gi3e09$ksp$1@ger.gmane.org>
References: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com>
	<gi36t2$nd$1@ger.gmane.org>
	<cba415ca0812140808w68ef1c64ia0c8fd17181c0eb@mail.gmail.com>
	<gi3e09$ksp$1@ger.gmane.org>
Message-ID: <cba415ca0812140923s574c6946sce566a9ae2dc1124@mail.gmail.com>

Hi,

thank you very much.

And how can i write single test which will tell me execution time of
this algorithm?

I need to write a table with number of data & execution time
comparison (and it should be linear in case of this algorithm)

Thanks!

D.

On Sun, Dec 14, 2008 at 5:58 PM, Alan Gauld <alan.gauld at btinternet.com> wrote:
> "David Hl?cik" <david at hlacik.eu> wrote
>
>> yes it is homework , this is result :
>>
>> #! /usr/bin/python
>> def sort(numbers):
>>       "sort n positive integers in O(n) provided that they are all < n^2"
>>       N = len(numbers) # get size of test numbers
>>
>>       buckets_mod = [[] for i in xrange(N)]
>>       buckets_sorted = [[] for i in xrange(N+1)]
>>
>>       # group numbers to buckets (list of numbers) with common modulus
>>       for n in numbers:
>>               buckets_mod[n % N].append(n)
>>       print "buckets_mod: %s" % buckets_mod
>
> It would be interesting to see if using a dictionasry aws a sparce
> array was any faster - it would save the initialisation step and
> reduce the number of accesses of empty lists.
>
>>       # check numbers in buckets
>>       for l in buckets_mod:
>>               for n in l:
>>                       buckets_sorted[n / N].append(n)
>>       print "buckets_sorted: %s" % buckets_sorted
>>
>>       # search through sorted buckets and return list of sorted numbers
>>       return [n for l in buckets_sorted for n in l]
>>
>> Hope it is optimal and OK, what you guys thinks?
>
> Its almost certainly not optimal but from some basic testing it seems to
> work and is linear as far as I can see (albeit with 5 loops over N).
>
> Alan G
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

From denis.spir at free.fr  Sun Dec 14 19:32:34 2008
From: denis.spir at free.fr (spir)
Date: Sun, 14 Dec 2008 19:32:34 +0100
Subject: [Tutor] stable algorithm
In-Reply-To: <cba415ca0812140923s574c6946sce566a9ae2dc1124@mail.gmail.com>
References: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com>	<gi36t2$nd$1@ger.gmane.org>	<cba415ca0812140808w68ef1c64ia0c8fd17181c0eb@mail.gmail.com>	<gi3e09$ksp$1@ger.gmane.org>
	<cba415ca0812140923s574c6946sce566a9ae2dc1124@mail.gmail.com>
Message-ID: <49455142.5030509@free.fr>

David Hl??ik a ?crit :
> Hi,
> 
> thank you very much.
> 
> And how can i write single test which will tell me execution time of
> this algorithm?
> 
> I need to write a table with number of data & execution time
> comparison (and it should be linear in case of this algorithm)
> 
> Thanks!
> 
> D.
> 
First, google will give you tons of links on the topic.
time.time() returns present time in ms
The func below is practicle, too.
denis

	
def timer(n,f,*args,**kw_args):
	t0 = time()
	for i in range(n):
		f(*args,**kw_args)
	t = time() - t0
	arg_str = ','.join(str(arg) for arg in args)
	kw_arg_str = ','+str(kw_args)[1:-1] if kw_args else ''
	print "%s(%s%s) %s time(s) <--> %0.3f s" % (f.__name__,arg_str,kw_arg_str,n,t)


From bermanrl at embarqmail.com  Sun Dec 14 19:48:26 2008
From: bermanrl at embarqmail.com (Robert Berman)
Date: Sun, 14 Dec 2008 13:48:26 -0500
Subject: [Tutor] reading inputs from keyboard
In-Reply-To: <4945517F.6060806@free.fr>
References: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
	<494540B7.7000609@embarqmail.com> <4945517F.6060806@free.fr>
Message-ID: <494554FA.7020800@embarqmail.com>

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From rabidpoobear at gmail.com  Sun Dec 14 19:58:43 2008
From: rabidpoobear at gmail.com (Luke Paireepinart)
Date: Sun, 14 Dec 2008 12:58:43 -0600
Subject: [Tutor] reading inputs from keyboard
In-Reply-To: <494554FA.7020800@embarqmail.com>
References: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
	<494540B7.7000609@embarqmail.com> <4945517F.6060806@free.fr>
	<494554FA.7020800@embarqmail.com>
Message-ID: <dfeb4470812141058s561c1c83m56997cd821f37545@mail.gmail.com>

A more gentle nudging in the correct direction is generally more
well-received.  Honestly, it doesn't help anyone to be rude, and we'll
all just think less of you for this unnecessary divergence.
If you're not going to at be witty and subtle about it, you may as
well direct them to Eric Raymond's article on how to ask smart
questions.  He's already written this chastisement, and better than
you.
Please don't pollute our space with noise and needless posturing.  If
your response is not going to be more helpful than "RTFM" or "GIYF"
perhaps you should reconsider hitting that send button.


On Sun, Dec 14, 2008 at 12:48 PM, Robert Berman <bermanrl at embarqmail.com> wrote:
> Rather than being impressed, perhaps you might consider performing the
> action.
>
> spir wrote:
>
> Robert Berman a ?crit :
>
> RTFM.
>
> how clever!
> I'm impressed...
> Denis
>
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>

From marc.tompkins at gmail.com  Sun Dec 14 20:04:54 2008
From: marc.tompkins at gmail.com (Marc Tompkins)
Date: Sun, 14 Dec 2008 11:04:54 -0800
Subject: [Tutor] reading inputs from keyboard
In-Reply-To: <494554FA.7020800@embarqmail.com>
References: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
	<494540B7.7000609@embarqmail.com> <4945517F.6060806@free.fr>
	<494554FA.7020800@embarqmail.com>
Message-ID: <40af687b0812141104h4294518fk6e198fdc5fc389ff@mail.gmail.com>

On Sun, Dec 14, 2008 at 10:48 AM, Robert Berman <bermanrl at embarqmail.com> wrote:
>
> Rather than being impressed, perhaps you might consider performing the action.
>
> spir wrote:
>
> Robert Berman a ?crit :
>
> RTFM.
>
> how clever!
> I'm impressed...
> Denis

Also, you might have noticed that Denis wasn't the original poster.
More of a community response, looks like.  We're ALL impressed, and
some of us do read the fine manual.
--
www.fsrtechnologies.com

From alan.gauld at btinternet.com  Sun Dec 14 20:21:50 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sun, 14 Dec 2008 19:21:50 -0000
Subject: [Tutor] stable algorithm
References: <cba415ca0812140438k3572ddbds4cad0ebf1ef9e0d6@mail.gmail.com>	<gi36t2$nd$1@ger.gmane.org>	<cba415ca0812140808w68ef1c64ia0c8fd17181c0eb@mail.gmail.com>	<gi3e09$ksp$1@ger.gmane.org><cba415ca0812140923s574c6946sce566a9ae2dc1124@mail.gmail.com>
	<49455142.5030509@free.fr>
Message-ID: <gi3mcm$eeg$1@ger.gmane.org>


"spir" <denis.spir at free.fr> wrote

>> And how can i write single test which will tell me execution time 
>> of
>> this algorithm?
> First, google will give you tons of links on the topic.
> time.time() returns present time in ms

You could also use the python profiler which will give you timing
information for just the sort function itself. That may be more
useful if trying to prove the linearity of your sort rather than of
the overall program including data production etc.

You should be able to write a function to generate a list of N
random numbers easily enough.... Now write a loop to do
that for 2,20,200,200 and 200,000 numbers.
Tabulate the results.

Alan G 



From sander.sweers at gmail.com  Sun Dec 14 20:43:21 2008
From: sander.sweers at gmail.com (Sander Sweers)
Date: Sun, 14 Dec 2008 20:43:21 +0100
Subject: [Tutor] reading inputs from keyboard
In-Reply-To: <494540B7.7000609@embarqmail.com>
References: <3eff71880812140439i4bce6028s5a350b97591da1db@mail.gmail.com>
	<494540B7.7000609@embarqmail.com>
Message-ID: <b65fbb130812141143y774bb0aw5168d5c793eea829@mail.gmail.com>

On Sun, Dec 14, 2008 at 18:21, Robert Berman <bermanrl at embarqmail.com> wrote:
> RTFM.

Thank you for your non contribution python tutor mailing list.The
minimum you could do is point to the FM which others luckily already
did.

Greets
Sander

From roadierich at googlemail.com  Mon Dec 15 02:42:47 2008
From: roadierich at googlemail.com (Rich Lovely)
Date: Mon, 15 Dec 2008 01:42:47 +0000
Subject: [Tutor] Working with lists
In-Reply-To: <3E0E214CD0DB42FDA20AEDE2265C51EE@AWA2>
References: <mailman.53.1229252420.31374.tutor@python.org>
	<3E0E214CD0DB42FDA20AEDE2265C51EE@AWA2>
Message-ID: <948041D5-B3A0-4034-9952-243F59DE3F15@googlemail.com>

Yeah, you could do that, but it was quite a revelation when I  
discovered itertools, and I'm just trying to share the love.

---
Richard "Roadie Rich" Lovely
Part of the JNP|UK Famille
www.theJNP.com

(Sent from my iPod - please allow me a few typos: it's a very small  
keyboard)

On 14 Dec 2008, at 14:46, "Paul McGuire" <ptmcg at austin.rr.com> wrote:

> Even simpler than Rich Lovely's:
>
>    newlist = [a+b for a,b in itertools.izip(l1[:-1], l1[1:])]
>
> is to just use the built-in zip:
>
>    newlist = [a+b for a,b in zip(l1[:-1], l1[1:])]
>
> since you can be sure that l1[:-1] and l1[1:] will always be the same
> length, so there is no need for a fill value (one of the  
> enhancements you
> get when using itertools.izip).
>
> I often use zip this way when I need to get each item and its next- 
> highest
> neighbor from a list.
>
> -- Paul
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor

From pyth0nc0d3r at gmail.com  Mon Dec 15 13:51:07 2008
From: pyth0nc0d3r at gmail.com (Lamonte Harris)
Date: Mon, 15 Dec 2008 06:51:07 -0600
Subject: [Tutor] Having Issues with CMD and the 'python' command
Message-ID: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>

Every time I start cmd on windows it requires me to "set
path=%path%;C:\python26" why? I'm getting annoyed...
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From bgailer at gmail.com  Mon Dec 15 14:31:30 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 15 Dec 2008 08:31:30 -0500
Subject: [Tutor] Having Issues with CMD and the 'python' command
In-Reply-To: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
References: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
Message-ID: <49465C32.7020200@gmail.com>

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From gmorris at serif.com  Fri Dec 12 18:47:09 2008
From: gmorris at serif.com (Gareth at Serif)
Date: Fri, 12 Dec 2008 09:47:09 -0800 (PST)
Subject: [Tutor] MP3Info class usage
In-Reply-To: <20081210140534.GM13722@inocybe.teonanacatl.org>
References: <20934673.post@talk.nabble.com>
	<20081210140534.GM13722@inocybe.teonanacatl.org>
Message-ID: <20980334.post@talk.nabble.com>


Okay, I've moved over to eyeD3.py... fif nothing else, the documentation for
it's usage is far superior.

However, I can't get anything to run.  The help gives examples of some
simple tasks, but as soon as I 'import eyeD3', not even calling any
functions within it, I start getting errors such as:

In eyeD3.py, the 'from eyeD3.tag import *;' line (and similar) didn't work
until I removed the 'eyeD3.' part and just imported 'tag'.

Then in tag.py, some of the class defs complained about undefined variables,
for example 'def link(self, f, v = ID3_ANY_VERSION)' needed to have quotes
around 'ID3_ANY_VERSION'.

Now these issues are addressed I have an error in mp3.py, 'class
EyeD3Driver(eyeD3.utils.FileHandler) NameError: name 'eyeD3' is not defined.

I'm baffled that I'm having to jump through so many hoops because I imported
eyeD3... is this typical?  What have I done wrong?

Cheers,
Gareth



Todd Zullinger wrote:
> 
> I'd recommend eyeD3? and/or mutagen? for tag reading.  Both are pretty
> easy to use.
> 
> ? http://eyed3.nicfit.net/
> ? http://code.google.com/p/quodlibet/wiki/Development/Mutagen
> 
> 

-- 
View this message in context: http://www.nabble.com/MP3Info-class-usage-tp20934673p20980334.html
Sent from the Python - tutor mailing list archive at Nabble.com.


From prologic at shortcircuit.net.au  Mon Dec 15 14:01:01 2008
From: prologic at shortcircuit.net.au (James Mills)
Date: Mon, 15 Dec 2008 23:01:01 +1000
Subject: [Tutor] Having Issues with CMD and the 'python' command
In-Reply-To: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
References: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
Message-ID: <e1a84d570812150501l68b61bd6v270be05280086ebe@mail.gmail.com>

"cmd" has _nothing_ to do with Python.

--JamesMills

--
-- "Problems are solved by method"



On Mon, Dec 15, 2008 at 10:51 PM, Lamonte Harris <pyth0nc0d3r at gmail.com> wrote:
> Every time I start cmd on windows it requires me to "set
> path=%path%;C:\python26" why? I'm getting annoyed...
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>

From rdmurray at bitdance.com  Mon Dec 15 14:13:11 2008
From: rdmurray at bitdance.com (rdmurray at bitdance.com)
Date: Mon, 15 Dec 2008 08:13:11 -0500 (EST)
Subject: [Tutor] Having Issues with CMD and the 'python' command
In-Reply-To: <e1a84d570812150501l68b61bd6v270be05280086ebe@mail.gmail.com>
References: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
	<e1a84d570812150501l68b61bd6v270be05280086ebe@mail.gmail.com>
Message-ID: <Pine.LNX.4.64.0812150804220.1995@kimball.webabinitio.net>

On Mon, 15 Dec 2008 at 23:01, James Mills wrote:
> On Mon, Dec 15, 2008 at 10:51 PM, Lamonte Harris <pyth0nc0d3r at gmail.com> wrote:
>> Every time I start cmd on windows it requires me to "set
>> path=%path%;C:\python26" why? I'm getting annoyed...
>
> "cmd" has _nothing_ to do with Python.
>

(Top posting corrected.)

But the answer is that you need to update your PATH string at the system
level.  You do that in Control Panel/System/Advanced/Environment variables
(it's a button on the advanced screen, which is something that confused
me the first time I went looking for it).

ObPython: you know, it occurs to me that Windows follows exactly the
opposite philosophy from Python when it comes to hierarchy.  Python's
Zen is "shallow is better than deep", whereas Windows' philosophy
is "deep is better than shallow".  Every release of Windows seems
to bury the things one needs to do to administer the system deeper
and deeper inside a nested set of windows...and every time I touch
Windows I am reminded how sensible the Python Zen is :)

--RDM

From kent37 at tds.net  Mon Dec 15 14:53:19 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 15 Dec 2008 08:53:19 -0500
Subject: [Tutor] Python Lib Files
In-Reply-To: <20081214094946.4k7u890c8wgw0okc@webmail4.isis.unc.edu>
References: <20081214094946.4k7u890c8wgw0okc@webmail4.isis.unc.edu>
Message-ID: <1c2a2c590812150553x12527410jfa53a005eda70031@mail.gmail.com>

On Sun, Dec 14, 2008 at 9:49 AM,  <btkuhn at email.unc.edu> wrote:
> Hello everyone,
>
> I discovered yesterday that the Python package has a number of built in
> example scripts in the /lib directory. Perhaps this is common knowledge but
> I did not know about it. I can't seem to find any kind of guide to the
> files, though. Is there a readme somewhere that someone can point me to, or
> perhaps documentation for the files online? I cant find anything on the
> python.org site. This is for version 2.5.

Those are not sample scripts, they are the standard library. There is
extensive documentation, for example
http://docs.python.org/library/
or for Python 2.5 see
http://www.python.org/doc/2.5.2/lib/lib.html

Kent

From alan.gauld at btinternet.com  Mon Dec 15 16:14:26 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 15 Dec 2008 15:14:26 -0000
Subject: [Tutor] Python Lib Files
References: <20081214094946.4k7u890c8wgw0okc@webmail4.isis.unc.edu>
	<1c2a2c590812150553x12527410jfa53a005eda70031@mail.gmail.com>
Message-ID: <gi5s8m$i2v$1@ger.gmane.org>

"Kent Johnson" <kent37 at tds.net> wrote

>> I discovered yesterday that the Python package has a number of 
>> built in
>> example scripts in the /lib directory.
>
> Those are not sample scripts, they are the standard library. There 
> is
> extensive documentation, for example

However there are some sample scripts in the Tools directory...
For example a regex checker and reindentation tool.

HTH,

Alan G. 



From alan.gauld at btinternet.com  Mon Dec 15 16:17:40 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 15 Dec 2008 15:17:40 -0000
Subject: [Tutor] Having Issues with CMD and the 'python' command
References: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
	<49465C32.7020200@gmail.com>
Message-ID: <gi5seo$iqb$1@ger.gmane.org>

"bob gailer" <bgailer at gmail.com> wrote

> Try this:
>
> Start->Settings->Control Panel->System->Advanced->Environment 
> Variables
> Highlight PATH under System Variables & Click Edit.
> Add ;C:\python26

And notice that Bob said ADD - DO NOT REPLACE the existing setting or
you will likely break stuff and its not easy to fix it afterwards 
unless
you have a full backup to hand!!

Alan G. 



From kent37 at tds.net  Mon Dec 15 16:22:10 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 15 Dec 2008 10:22:10 -0500
Subject: [Tutor] Ask a class for it's methods
In-Reply-To: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
References: <376fbdcf0812121506y200d9374ufb67a5e2ff35c0@mail.gmail.com>
Message-ID: <1c2a2c590812150722o7150a45ax42592997be847175@mail.gmail.com>

On Fri, Dec 12, 2008 at 6:06 PM, Shrutarshi Basu
<technorapture at gmail.com> wrote:
> Is there a way to ask an object for a list of it's
> methods (with argument requirements if possible)?

Take a look at the inspect module. If it does not directly give you
what you need, look at the source - it looks at function attributes
that you can directly access.

Kent

From benjamin.kaplan at case.edu  Mon Dec 15 16:56:29 2008
From: benjamin.kaplan at case.edu (Benjamin Kaplan)
Date: Mon, 15 Dec 2008 10:56:29 -0500
Subject: [Tutor] Having Issues with CMD and the 'python' command
In-Reply-To: <Pine.LNX.4.64.0812150804220.1995@kimball.webabinitio.net>
References: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
	<e1a84d570812150501l68b61bd6v270be05280086ebe@mail.gmail.com>
	<Pine.LNX.4.64.0812150804220.1995@kimball.webabinitio.net>
Message-ID: <ec96e1390812150756l5e720880t2fca05e4b23ffb57@mail.gmail.com>

On Mon, Dec 15, 2008 at 8:13 AM, <rdmurray at bitdance.com> wrote:

> On Mon, 15 Dec 2008 at 23:01, James Mills wrote:
>
>> On Mon, Dec 15, 2008 at 10:51 PM, Lamonte Harris <pyth0nc0d3r at gmail.com>
>> wrote:
>>
>>> Every time I start cmd on windows it requires me to "set
>>> path=%path%;C:\python26" why? I'm getting annoyed...
>>>
>>
>> "cmd" has _nothing_ to do with Python.
>>
>>
> (Top posting corrected.)
>
> But the answer is that you need to update your PATH string at the system
> level.  You do that in Control Panel/System/Advanced/Environment variables
> (it's a button on the advanced screen, which is something that confused
> me the first time I went looking for it).
>
> ObPython: you know, it occurs to me that Windows follows exactly the
> opposite philosophy from Python when it comes to hierarchy.  Python's
> Zen is "shallow is better than deep", whereas Windows' philosophy
> is "deep is better than shallow".  Every release of Windows seems
> to bury the things one needs to do to administer the system deeper
> and deeper inside a nested set of windows...and every time I touch
> Windows I am reminded how sensible the Python Zen is :)
>

It's not a question of sensibility. It's a question of purpose. The Zen is
the philosophy of a language that tries to be easy to learn and easy to use.
Python is used by programmers who want to experiment with it, but who
usually know enough not to os.system("rm -r /") or anything similar.
Windows, on the other hand, wants to hide everything that can potentially
ruin the system as deep as possible so that many of the idiots who use that
system don't do stupid things like delete the registry, wipe the environment
settings, turn off the "Nag Screen" (UAC), and other things of that nature.



> --RDM
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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From fisher.127 at wright.edu  Mon Dec 15 17:32:09 2008
From: fisher.127 at wright.edu (Bradford Fisher)
Date: Mon, 15 Dec 2008 11:32:09 -0500
Subject: [Tutor] Creating IDLE Shortcut
Message-ID: <6640dc74df37.49464039@wright.edu>

Hello,

Does anyone know the proper method for re-creating the Windows XP shortcut for IDLE?  I (not thinking clearly) deleted the original and now am not sure how to go about fixing the problem.  I've attempted creating a shortcut and linking it to pythonw.exe with the target idle.pyw, but when loading IDLE with that shortcut all of my settings are lost and the load process is far greater.

- Brad

From jfabiani at yolo.com  Mon Dec 15 19:18:28 2008
From: jfabiani at yolo.com (johnf)
Date: Mon, 15 Dec 2008 10:18:28 -0800
Subject: [Tutor] need to clean a string
Message-ID: <200812151018.28151.jfabiani@yolo.com>

Hi,
I have a string that I need to extract just the sql	 statement. 
The following is the string
\000\000\000
\000\000\000\000
\000.
\000\000\000
\0000\000\000\000

\000$\000\000\000\000
\000(
\000\000\000
\000X\000\000\000\000
\000,

\000\000\000
\000P\000\000\000\000
\000Q\000\000\000\000
\000R\000
\000\000\000
\000/\000\000\000?\000\000\000
\000%????\000\000\000

\000'????\000\000\000
\000+brttyp\000?\000\000\000
\000*SELECT 
Brttyp.ctrscode, Brttyp.cdescript, Brttyp.ctrstype, Brttyp.cstatus, 
Brttyp.lreqno, Brttyp.dcreate FROM  brttyp Brttyp WHERE  Brttyp.ctrscode = 
( ?gcKey1 )\000\000\000\000
\000 AMCONNECT\000\000\000\000
\000)
\000\000\000
\000
\000\000\000
 \000\000\000
\000BR Transaction Code 
File\000

How can I get rid of all the junk?
 
I can find the '*' with str.find('*') but I can't use find '\000' to get to 
the end?
-- 
John Fabiani

From andreas at kostyrka.org  Mon Dec 15 20:31:12 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Mon, 15 Dec 2008 20:31:12 +0100
Subject: [Tutor] need to clean a string
In-Reply-To: <200812151018.28151.jfabiani@yolo.com>
References: <200812151018.28151.jfabiani@yolo.com>
Message-ID: <20081215203112.62e7b58b@andi-lap>

Am Mon, 15 Dec 2008 10:18:28 -0800
schrieb johnf <jfabiani at yolo.com>:

> Hi,
> I have a string that I need to extract just the sql
> statement. The following is the string
> \000\000\000
\000\000\000\000
\000.
\000\000\000
\0000\000\000\000

> \000$\000\000\000\000
\000(
\000\000\000
\000X\000\000\000\000
\000,

> \000\000\000
\000P\000\000\000\000
\000Q\000\000\000\000
\000R\000
> \000\000\000
\000/\000\000\000?\000\000\000
\000%????\000\000\000

> \000'????\000\000\000
\000+brttyp\000?\000\000\000
\000*SELECT 
> Brttyp.ctrscode, Brttyp.cdescript, Brttyp.ctrstype, Brttyp.cstatus, 
> Brttyp.lreqno, Brttyp.dcreate FROM  brttyp Brttyp WHERE
> Brttyp.ctrscode = ( ?gcKey1 )\000\000\000\000
\000
> AMCONNECT\000\000\000\000
\000) \000\000\000
\000
\000\000\000

> \000\000\000
\000BR Transaction Code File\000
> 
> How can I get rid of all the junk?
>  
> I can find the '*' with str.find('*') but I can't use find '\000' to
> get to the end?

str.find has an optional second parameter specifying the start where to
search:

Given the above string as str, you can do:

start_pos = str.find('*')
sql = None
if start_pos != -1:
    end_pos = str.find('\0', start_pos)
    if end_pos == -1:
        end_pos = len(str)
    sql = str[start_pos:end_pos]

Andreas

From mlknack at gmail.com  Mon Dec 15 21:33:57 2008
From: mlknack at gmail.com (Mary Lou Knack)
Date: Mon, 15 Dec 2008 13:33:57 -0700
Subject: [Tutor] what does the "@" operator mean?
Message-ID: <221405905FE34478B30A32066A739A26@MLKsHP>

I'm looking at some code from Enthought's ETS examples and ran across the following statement:

@mayavi2.standalone

I have no idea what the "@" operator means, if anything.  I tried searching for it in the documentation (locally and online), but no luck.  Or rather, the local (windows) help said it couldn't search for that phrase (@) and the online search turned up a bazillion hits and I don't know how to refine the search.

Knowledge isn't necessary for me to proceed, but it sure would be nice.  Thanks.

Mary Lou Knack
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From marc.tompkins at gmail.com  Mon Dec 15 21:42:26 2008
From: marc.tompkins at gmail.com (Marc Tompkins)
Date: Mon, 15 Dec 2008 12:42:26 -0800
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <221405905FE34478B30A32066A739A26@MLKsHP>
References: <221405905FE34478B30A32066A739A26@MLKsHP>
Message-ID: <40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>

On Mon, Dec 15, 2008 at 12:33 PM, Mary Lou Knack <mlknack at gmail.com> wrote:
> I'm looking at some code from Enthought's ETS examples and ran across the
> following statement:
>
> @mayavi2.standalone
>
> I have no idea what the "@" operator means, if anything.  I tried searching
> for it in the documentation (locally and online), but no luck.  Or rather,
> the local (windows) help said it couldn't search for that phrase (@) and the
> online search turned up a bazillion hits and I don't know how to refine the
> search.

It indicates a decorator.
Try this:
http://en.wikipedia.org/wiki/Python_syntax_and_semantics#Decorators

If you're just starting out in Python, decorators can be hard to get
your head around...
-- 
www.fsrtechnologies.com

From jfabiani at yolo.com  Mon Dec 15 21:43:46 2008
From: jfabiani at yolo.com (johnf)
Date: Mon, 15 Dec 2008 12:43:46 -0800
Subject: [Tutor] need to clean a string
In-Reply-To: <20081215203112.62e7b58b@andi-lap>
References: <200812151018.28151.jfabiani@yolo.com>
	<20081215203112.62e7b58b@andi-lap>
Message-ID: <200812151243.46677.jfabiani@yolo.com>

On Monday 15 December 2008 11:31:12 am Andreas Kostyrka wrote:
> Am Mon, 15 Dec 2008 10:18:28 -0800
>
> schrieb johnf <jfabiani at yolo.com>:
> > Hi,
> > I have a string that I need to extract just the sql
> > statement. The following is the string
> > \000\000\000
\000\000\000\000
\000.
\000\000\000
\0000\000\000\000
> >

> > \000$\000\000\000\000
\000(
\000\000\000
\000X\000\000\000\000
\000,

> > \000\000\000
\000P\000\000\000\000
\000Q\000\000\000\000
\000R\000
> > \000\000\000
\000/\000\000\000?\000\000\000
\000%????\000\000\000

> > \000'????\000\000\000
\000+brttyp\000?\000\000\000
\000*SELECT
> > Brttyp.ctrscode, Brttyp.cdescript, Brttyp.ctrstype, Brttyp.cstatus,
> > Brttyp.lreqno, Brttyp.dcreate FROM  brttyp Brttyp WHERE
> > Brttyp.ctrscode = ( ?gcKey1 )\000\000\000\000
\000
> > AMCONNECT\000\000\000\000
\000) \000\000\000
\000
\000\000\000

> > \000\000\000
\000BR Transaction Code File\000
> >
> > How can I get rid of all the junk?
> >
> > I can find the '*' with str.find('*') but I can't use find '\000' to
> > get to the end?
>
> str.find has an optional second parameter specifying the start where to
> search:
>
> Given the above string as str, you can do:
>
> start_pos = str.find('*')
> sql = None
> if start_pos != -1:
>     end_pos = str.find('\0', start_pos)
>     if end_pos == -1:
>         end_pos = len(str)
>     sql = str[start_pos:end_pos]
>
> Andreas

Thanks I got it done just as you explained.  What was interesting was my 
editor showed '\x000'  and not '\000'  so I was always looking for the wrong 
thing.  I thought I was doing it wrong.   Then while re-reading the message I 
sent to this list I noticed the lack of the 'x'.  And sure enough that was 
the problem.  Thanks for your help.



-- 
John Fabiani

From andreas at kostyrka.org  Mon Dec 15 23:04:11 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Mon, 15 Dec 2008 23:04:11 +0100
Subject: [Tutor] need to clean a string
In-Reply-To: <200812151243.46677.jfabiani@yolo.com>
References: <200812151018.28151.jfabiani@yolo.com>
	<20081215203112.62e7b58b@andi-lap>
	<200812151243.46677.jfabiani@yolo.com>
Message-ID: <20081215230411.67caa615@andi-lap>

Am Mon, 15 Dec 2008 12:43:46 -0800
schrieb johnf <jfabiani at yolo.com>:

> On Monday 15 December 2008 11:31:12 am Andreas Kostyrka wrote:
> > Am Mon, 15 Dec 2008 10:18:28 -0800
> >
> > schrieb johnf <jfabiani at yolo.com>:
> > > Hi,
> > > I have a string that I need to extract just the sql
> > > statement. The following is the string
> > > \000\000\000
\000\000\000\000
\000.
\000\000\000
\0000\000\000\000
> > >

> > > \000$\000\000\000\000
\000(
\000\000\000
\000X\000\000\000\000
\000,

> > > \000\000\000
\000P\000\000\000\000
\000Q\000\000\000\000
\000R\000
> > > \000\000\000
\000/\000\000\000?\000\000\000
\000%????\000\000\000

> > > \000'????\000\000\000
\000+brttyp\000?\000\000\000
\000*SELECT
> > > Brttyp.ctrscode, Brttyp.cdescript, Brttyp.ctrstype,
> > > Brttyp.cstatus, Brttyp.lreqno, Brttyp.dcreate FROM  brttyp Brttyp
> > > WHERE Brttyp.ctrscode = ( ?gcKey1 )\000\000\000\000
\000
> > > AMCONNECT\000\000\000\000
\000) \000\000\000
\000
\000\000\000

> > > \000\000\000
\000BR Transaction Code File\000
> > >
> > > How can I get rid of all the junk?
> > >
> > > I can find the '*' with str.find('*') but I can't use find '\000'
> > > to get to the end?
> >
> > str.find has an optional second parameter specifying the start
> > where to search:
> >
> > Given the above string as str, you can do:
> >
> > start_pos = str.find('*')
> > sql = None
> > if start_pos != -1:
> >     end_pos = str.find('\0', start_pos)
> >     if end_pos == -1:
> >         end_pos = len(str)
> >     sql = str[start_pos:end_pos]
> >
> > Andreas
> 
> Thanks I got it done just as you explained.  What was interesting was
> my editor showed '\x000'  and not '\000'  so I was always looking for
> the wrong thing.  I thought I was doing it wrong.   Then while
> re-reading the message I sent to this list I noticed the lack of the
> 'x'.  And sure enough that was the problem.  Thanks for your help.

Well \xHH is the hexadecimal notation, while \OOO is the octal
notation. The problem is that \x000 means the 00 byte followed the
character 0.

Andreas

> 
> 
> 

From technorapture at gmail.com  Mon Dec 15 23:38:51 2008
From: technorapture at gmail.com (Shrutarshi Basu)
Date: Mon, 15 Dec 2008 17:38:51 -0500
Subject: [Tutor] Reading module to import from a string
Message-ID: <376fbdcf0812151438w53c8f3f7rc1dc481b524282bc@mail.gmail.com>

Suppose I have a module that I want to import called ImMod1 that's
saved in a variable like so:

var = "ImMod1"

Is there some way to import ImMod1 by using var?
Thanks,
Basu
-- 
The ByteBaker :
http://www.bytebaker.com

From cbc at unc.edu  Mon Dec 15 23:49:03 2008
From: cbc at unc.edu (Chris Calloway)
Date: Mon, 15 Dec 2008 17:49:03 -0500
Subject: [Tutor] Reading module to import from a string
In-Reply-To: <376fbdcf0812151438w53c8f3f7rc1dc481b524282bc@mail.gmail.com>
References: <376fbdcf0812151438w53c8f3f7rc1dc481b524282bc@mail.gmail.com>
Message-ID: <4946DEDF.7090503@unc.edu>

On 12/15/2008 5:38 PM, Shrutarshi Basu wrote:
> Suppose I have a module that I want to import called ImMod1 that's
> saved in a variable like so:
> 
> var = "ImMod1"
> 
> Is there some way to import ImMod1 by using var?

http://stackoverflow.com/questions/67631/how-to-import-module-from-file-name

-- 
Sincerely,

Chris Calloway
http://www.secoora.org
office: 332 Chapman Hall   phone: (919) 599-3530
mail: Campus Box #3300, UNC-CH, Chapel Hill, NC 27599




From cbc at unc.edu  Mon Dec 15 23:50:50 2008
From: cbc at unc.edu (Chris Calloway)
Date: Mon, 15 Dec 2008 17:50:50 -0500
Subject: [Tutor] Reading module to import from a string
In-Reply-To: <376fbdcf0812151438w53c8f3f7rc1dc481b524282bc@mail.gmail.com>
References: <376fbdcf0812151438w53c8f3f7rc1dc481b524282bc@mail.gmail.com>
Message-ID: <4946DF4A.9040802@unc.edu>

On 12/15/2008 5:38 PM, Shrutarshi Basu wrote:
> Suppose I have a module that I want to import called ImMod1 that's
> saved in a variable like so:
> 
> var = "ImMod1"
> 
> Is there some way to import ImMod1 by using var?

http://docs.python.org/library/imp.html

-- 
Sincerely,

Chris Calloway
http://www.secoora.org
office: 332 Chapman Hall   phone: (919) 599-3530
mail: Campus Box #3300, UNC-CH, Chapel Hill, NC 27599




From s4027340 at student.uq.edu.au  Tue Dec 16 01:38:48 2008
From: s4027340 at student.uq.edu.au (Mr Gerard Kelly)
Date: Tue, 16 Dec 2008 10:38:48 +1000
Subject: [Tutor] numarray issues
Message-ID: <1b9761ca94.1ca941b976@uq.edu.au>

Hello, I am a python beginner, and I have a question about scalars vs
arrays.

I am making a (very simple) code, and part of it is:

from numarray import *
from math import *

def source(x,y):
  f=sin(x)
  return f

a=4.

m=10

dx=a/(m+1.)

x=zeros([m,1], Float)

print x[0]

print func(x[0])

When I run this code, I get:

[ 0.]
0.0

However, if I change the line f=sin(x) to f=2*x, I will get:

[ 0.]
[ 0.]

Why does func(x[0]) return a scalar for sin(x), but returns an array for
2*x?

If I want a scalar returned for f=2*x, I need to put in func(x[0,0]).
Why do x[0] and x[0,0] both work for sin(x), but only x[0,0] will work
for 2*x?

From cbc at unc.edu  Mon Dec 15 22:22:16 2008
From: cbc at unc.edu (Chris Calloway)
Date: Mon, 15 Dec 2008 16:22:16 -0500
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
Message-ID: <4946CA88.5070903@unc.edu>

On 12/15/2008 3:42 PM, Marc Tompkins wrote:
 > If you're just starting out in Python, decorators can be hard to get
 > your head around...

This would be a huge help:

http://www.ddj.com/web-development/184406073

-- 
Sincerely,

Chris Calloway
http://www.secoora.org
office: 332 Chapman Hall   phone: (919) 599-3530
mail: Campus Box #3300, UNC-CH, Chapel Hill, NC 27599


From alan.gauld at btinternet.com  Tue Dec 16 01:58:56 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 16 Dec 2008 00:58:56 -0000
Subject: [Tutor] Creating IDLE Shortcut
References: <6640dc74df37.49464039@wright.edu>
Message-ID: <gi6ugk$ag4$1@ger.gmane.org>


"Bradford Fisher" <fisher.127 at wright.edu> wrote 

> I've attempted creating a shortcut and linking it to pythonw.exe 

The one the installer created on my PC is a shortcut to:

C:\Python24\Tools\scripts\idle.pyw

with a start-in directory of

C:\Python24\Tools\scripts

HTH,

Alan G.


From alan.gauld at btinternet.com  Tue Dec 16 02:03:55 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 16 Dec 2008 01:03:55 -0000
Subject: [Tutor] what does the "@" operator mean?
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
Message-ID: <gi6upv$bek$1@ger.gmane.org>


"Marc Tompkins" <marc.tompkins at gmail.com> wrote

> If you're just starting out in Python, decorators can be hard to get
> your head around...

I've been using Python for oover 10 years and still find decorators
hard to get my head around! :-)

I confess I'm not a fan, they go against the Python spirit of
explicit is best in my opinion. If I'm calling a function I like to
know I'm calling a function... I know they make the code look
pretty but IMHO they are a pain to debug and I'm never totally
convinced I've got it exactly right.

Alan G 



From bgailer at gmail.com  Tue Dec 16 02:19:34 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 15 Dec 2008 20:19:34 -0500
Subject: [Tutor] numarray issues
In-Reply-To: <1b9761ca94.1ca941b976@uq.edu.au>
References: <1b9761ca94.1ca941b976@uq.edu.au>
Message-ID: <49470226.4000303@gmail.com>

Mr Gerard Kelly wrote:
> Hello, I am a python beginner, and I have a question about scalars vs
> arrays.
>
> I am making a (very simple) code, and part of it is:
>
> from numarray import *
> from math import *
>
> def source(x,y):
>   f=sin(x)
>   return f
>
> a=4.
>
> m=10
>
> dx=a/(m+1.)
>
> x=zeros([m,1], Float)
>
> print x[0]
>
> print func(x[0])
>
> When I run this code, I get:
>
> [ 0.]
> 0.0
>
> However, if I change the line f=sin(x) to f=2*x, I will get:
>
> [ 0.]
> [ 0.]
>
> Why does func(x[0]) return a scalar for sin(x), but returns an array for
> 2*x?
>
> If I want a scalar returned for f=2*x, I need to put in func(x[0,0]).
> Why do x[0] and x[0,0] both work for sin(x), but only x[0,0] will work
> for 2*x?
>   

sin() expects a scalar value.
x[0] is a 1 element array.
numarray magically converts the 1 element array to a scalar.
x[0]*2 multiplies each element of the array by 2 giving an array result.

> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From bgailer at gmail.com  Tue Dec 16 02:49:04 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 15 Dec 2008 20:49:04 -0500
Subject: [Tutor] numarray issues
In-Reply-To: <1f50f22726.227261f50f@uq.edu.au>
References: <1f50f22726.227261f50f@uq.edu.au>
Message-ID: <49470910.30509@gmail.com>

An HTML attachment was scrubbed...
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From mlknack at gmail.com  Tue Dec 16 03:15:57 2008
From: mlknack at gmail.com (Mary Lou Knack)
Date: Mon, 15 Dec 2008 19:15:57 -0700
Subject: [Tutor] what does the "@" operator mean?
References: <221405905FE34478B30A32066A739A26@MLKsHP><40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<4946CA88.5070903@unc.edu>
Message-ID: <A1DF57F454184615B178809559888A4A@MLKsHP>

Thanks Chris & Marc

I certainly don't need to know about decorators at this stage of my 
development.  Maybe I'll be able to avoid them entirely....

Mary Lou

----- Original Message ----- 
From: "Chris Calloway" <cbc at unc.edu>
To: <tutor at python.org>
Sent: Monday, December 15, 2008 2:22 PM
Subject: Re: [Tutor] what does the "@" operator mean?


> On 12/15/2008 3:42 PM, Marc Tompkins wrote:
> > If you're just starting out in Python, decorators can be hard to get
> > your head around...
>
> This would be a huge help:
>
> http://www.ddj.com/web-development/184406073
>
> -- 
> Sincerely,
>
> Chris Calloway
> http://www.secoora.org
> office: 332 Chapman Hall   phone: (919) 599-3530
> mail: Campus Box #3300, UNC-CH, Chapel Hill, NC 27599
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor 


From marc.tompkins at gmail.com  Tue Dec 16 03:33:01 2008
From: marc.tompkins at gmail.com (Marc Tompkins)
Date: Mon, 15 Dec 2008 18:33:01 -0800
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <gi6upv$bek$1@ger.gmane.org>
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<gi6upv$bek$1@ger.gmane.org>
Message-ID: <40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>

On Mon, Dec 15, 2008 at 5:03 PM, Alan Gauld <alan.gauld at btinternet.com> wrote:
>
> "Marc Tompkins" <marc.tompkins at gmail.com> wrote
>
>> If you're just starting out in Python, decorators can be hard to get
>> your head around...
>
> I've been using Python for oover 10 years and still find decorators
> hard to get my head around! :-)
>
> I confess I'm not a fan, they go against the Python spirit of
> explicit is best in my opinion. If I'm calling a function I like to
> know I'm calling a function... I know they make the code look
> pretty but IMHO they are a pain to debug and I'm never totally
> convinced I've got it exactly right.
>
> Alan G
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

I'm sorry I left it as flat as I did - that Dr. Dobbs article is a
pretty good explanation, and there's an article somewhere in the
Effbot bookshelf that does a decent job - but I couldn't find either
one at that moment.

I've only been using Python for a couple of years now, but my
experience so far is the same as yours: decorators make my head hurt.
Even in the Dr. Dobbs article, the examples seem horribly contrived.
There must be plenty of programmers who use decorators all the time
and would feel lost without them, but I have yet to see a compelling
use case.  (It's always something like "Here's another useless,
made-up situation.  We could handle it in a straightforward way, but
wouldn't it be cooler if we used a decorator instead?")

Actually, I'm being unnecessarily harsh: I can imagine a theoretical
case, where there is some operation you wish to apply to several
functions, and you don't want to write the code more than once.
(Wrapping a timer around functions comes to mind.)  But I've never run
across a situation where a decorator actually seemed like the best way
to do it, and (almost) all of the articles on the subject feel like
they were written to check an action item off the editor's to-do list:
this book won't be complete unless we mention decorators, so better
slop something together.

Does anybody who reads this list use decorators and have a nice word
to say about them?  I'd be interested to hear it.

-- 
www.fsrtechnologies.com

p.s. - Is anybody else as sick of the phrase "syntactic sugar" as I am?

From steve at alchemy.com  Tue Dec 16 03:50:17 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Mon, 15 Dec 2008 18:50:17 -0800
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>
References: <221405905FE34478B30A32066A739A26@MLKsHP>	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>	<gi6upv$bek$1@ger.gmane.org>
	<40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>
Message-ID: <49471769.3090604@alchemy.com>

Marc Tompkins wrote:
> On Mon, Dec 15, 2008 at 5:03 PM, Alan Gauld <alan.gauld at btinternet.com> wrote:
>> I've been using Python for oover 10 years and still find decorators
>> hard to get my head around! :-)
> I've only been using Python for a couple of years now, but my
> experience so far is the same as yours: decorators make my head hurt.

Interesting.  I actually rather like them and find them to be a tool to 
clean up code quite a bit.  Python's ability to have classes offer 
"attributes" which are really handled by wrapper functions is a similar 
animal (in the sense that they can be very nice but also could be 
horribly abused to make smelly code).

That said, I don't find myself using them too often.  Sort of like a 
special seasoning you add to the occasional dish but exotic enough to 
taste weird if you used it all the time.

For example, creating web apps in TurboGears uses decorators to expose 
methods, apply error handling and output templates without unnecessarily 
cluttering all your method definitions.

From tesujicamera at gmail.com  Tue Dec 16 05:01:12 2008
From: tesujicamera at gmail.com (Lee Meredith)
Date: Mon, 15 Dec 2008 23:01:12 -0500
Subject: [Tutor] problems finding position in list and changing it for GO
	game
Message-ID: <913d9be80812152001k6bcd48d9id8990ad97db99185@mail.gmail.com>

Hi
I am looking for some help if you have or worked with pygame or not
I'm sure if you have not you could still help me
I am working on a  *GO game* no AI a analog behavior only
I have the stones going to the board and switching colors between black and
white
but I want to take *stones/pieces* off and count them
and if you don't play go it's okay as well but might help

the MOUSEBUTTONDOWN gives the black0 XandYpositions with the*.append*
how do I reference the address in the list by using XandYpositions
Then replace them or take it out off the list

This code puts out an error when you hit the letter "b"

Traceback (most recent call last):
  File "C:/Users/Lee/Desktop/pyGame01/GO/GO_1_2_3.py", line 46, in <module>
    for stone in len(black0):
TypeError: 'int' object is not iterable

Which I'm not really sure what that means or how to remedy it as well

Thank you everyone

## geting there black and white stones alternate now the issue
## of taking the stones off the board
## Or more precisely to .insert into the list at an address that I detected
by finding the X. and the Y. by using the
## if event.pos == range( black0[stone][0] - (stoneWidth/2),
black0[stone][0] + ((stoneWidth/2)+1)):
import pygame
from pygame.locals import *
from sys import exit
pygame.init()
screen = pygame.display.set_mode((758, 758), 0, 32)
##Color
color0 = (0,255)

b = 0

white0 = [] #white0
black0 = [] #black0

stoneWidth = 20

while True:
    pressed_keys = pygame.key.get_pressed()
    for event in pygame.event.get():
        if event.type == QUIT:
            exit()
        if event.type == MOUSEBUTTONDOWN:##makes a variable out of the X.
and Y. coordinates
            if b==0:
                b=1
                black0.append(event.pos)##black0.append [X. and Y.]
                black1.append(event.pos)
                print "black points1"
                print black0
                print
            else:
                b=0
                white0.append(event.pos)
                white1.append(event.pos)
                print "white points"
                print white0
                print
        if event.type == KEYDOWN:
            if event.key == K_b:
                print "cut black"
                for stone in len(black0):##I'm not sure here either   is
this the way I would look for detection of mouse in the range
Circle                    if event.pos == range( black0[stone][0] -
(stoneWidth/2), black0[stone][0] + ((stoneWidth/2)+1)):
                        ## this is where I get confused what should I do
<<<<<<<
                        ## black0.insert(event.pos,0)
                    if event.pos == range( black0[stone][1] -
(stoneWidth/2), black0[stone][1] + ((stoneWidth/2)+1)):
                        ## this is where I get confused what should I do
<<<<<<<
                        ##black0.insert(event.pos,1)

    screen.fill((229,181,83))
    screen.lock()
    for white in white0: #you're drawing
        pygame.draw.circle(screen, (color0[1],color0[1],color0[1]), white,
20)
    for black in black0:
        pygame.draw.circle(screen, (color0[0],color0[0],color0[0]), black,
20)
    screen.unlock()
    pygame.display.update()
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From srilyk at gmail.com  Tue Dec 16 05:45:48 2008
From: srilyk at gmail.com (W W)
Date: Mon, 15 Dec 2008 22:45:48 -0600
Subject: [Tutor] problems finding position in list and changing it for
	GO game
In-Reply-To: <913d9be80812152001k6bcd48d9id8990ad97db99185@mail.gmail.com>
References: <913d9be80812152001k6bcd48d9id8990ad97db99185@mail.gmail.com>
Message-ID: <333efb450812152045h469d7f29p1c4db4a40a2aae0c@mail.gmail.com>

On Mon, Dec 15, 2008 at 10:01 PM, Lee Meredith <tesujicamera at gmail.com>wrote:

> <snip>
> the MOUSEBUTTONDOWN gives the black0 XandYpositions with the*.append*
> how do I reference the address in the list by using XandYpositions
> Then replace them or take it out off the list
>
> This code puts out an error when you hit the letter "b"


This error is pretty verbose, as most python errors are:


> Traceback (most recent call last):
>   File "C:/Users/Lee/Desktop/pyGame01/GO/GO_1_2_3.py", line 46, in <module>


This line tells you that the offending statement, the one that "broke" your
program/contained a bug is on line 46. Usually this is a pretty good place
to start looking.


>     for stone in len(black0):


That tells you the statement that broke


> TypeError: 'int' object is not iterable


This line tells you /why/ it broke, which is usually the most important bit,
and this one gives you some good information. First off, it tells you the
type of error, in this case TypeError. AFAIK, this means you tried to do
something with a type that isn't allowed. In this case you tried to iterate
over an integer. This doesn't work.

Would you expect this to work?
for num in 7:

Hopefully your experience with python will tell you that it would be silly
to think of such a thing.However, if you were to say:

for num in range(0, 7): - that would be a little more sane. In this case,
you are performing something similar to the prior example: you're trying to
iterate over a single integer. len() returns the length of the list as an
integer value.

If you look at some of your other statements you have "for white in white0:"
- a list is iterable, and white0 is a list.

I hope this helps,
Wayne


>
>
> Which I'm not really sure what that means or how to remedy it as well
>
> Thank you everyone
>
> ## geting there black and white stones alternate now the issue
> ## of taking the stones off the board
> ## Or more precisely to .insert into the list at an address that I detected
> by finding the X. and the Y. by using the
> ## if event.pos == range( black0[stone][0] - (stoneWidth/2),
> black0[stone][0] + ((stoneWidth/2)+1)):
> import pygame
> from pygame.locals import *
> from sys import exit
> pygame.init()
> screen = pygame.display.set_mode((758, 758), 0, 32)
> ##Color
> color0 = (0,255)
>
> b = 0
>
> white0 = [] #white0
> black0 = [] #black0
>
> stoneWidth = 20
>
> while True:
>     pressed_keys = pygame.key.get_pressed()
>     for event in pygame.event.get():
>         if event.type == QUIT:
>             exit()
>         if event.type == MOUSEBUTTONDOWN:##makes a variable out of the X.
> and Y. coordinates
>             if b==0:
>                 b=1
>                 black0.append(event.pos)##black0.append [X. and Y.]
>                 black1.append(event.pos)
>                 print "black points1"
>                 print black0
>                 print
>             else:
>                 b=0
>                 white0.append(event.pos)
>                 white1.append(event.pos)
>                 print "white points"
>                 print white0
>                 print
>         if event.type == KEYDOWN:
>             if event.key == K_b:
>                 print "cut black"
>                 for stone in len(black0):##I'm not sure here either   is
> this the way I would look for detection of mouse in the range
> Circle                    if event.pos == range( black0[stone][0] -
> (stoneWidth/2), black0[stone][0] + ((stoneWidth/2)+1)):
>                         ## this is where I get confused what should I do
> <<<<<<<
>                         ## black0.insert(event.pos,0)
>                     if event.pos == range( black0[stone][1] -
> (stoneWidth/2), black0[stone][1] + ((stoneWidth/2)+1)):
>                         ## this is where I get confused what should I do
> <<<<<<<
>                         ##black0.insert(event.pos,1)
>
>     screen.fill((229,181,83))
>     screen.lock()
>     for white in white0: #you're drawing
>         pygame.draw.circle(screen, (color0[1],color0[1],color0[1]), white,
> 20)
>     for black in black0:
>         pygame.draw.circle(screen, (color0[0],color0[0],color0[0]), black,
> 20)
>     screen.unlock()
>     pygame.display.update()
>
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>


-- 
To be considered stupid and to be told so is more painful than being called
gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness,
every vice, has found its defenders, its rhetoric, its ennoblement and
exaltation, but stupidity hasn't. - Primo Levi
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From tmz at pobox.com  Tue Dec 16 05:50:37 2008
From: tmz at pobox.com (Todd Zullinger)
Date: Mon, 15 Dec 2008 23:50:37 -0500
Subject: [Tutor] MP3Info class usage
In-Reply-To: <20980334.post@talk.nabble.com>
References: <20934673.post@talk.nabble.com>
	<20081210140534.GM13722@inocybe.teonanacatl.org>
	<20980334.post@talk.nabble.com>
Message-ID: <20081216045037.GA12325@inocybe.teonanacatl.org>

Gareth at Serif wrote:
> Okay, I've moved over to eyeD3.py... fif nothing else, the
> documentation for it's usage is far superior.
> 
> However, I can't get anything to run.  The help gives examples of
> some simple tasks, but as soon as I 'import eyeD3', not even calling
> any functions within it, I start getting errors such as:
> 
> In eyeD3.py, the 'from eyeD3.tag import *;' line (and similar)
> didn't work until I removed the 'eyeD3.' part and just imported
> 'tag'.

How have you installed eyeD3?  Perhaps there's something wrong with
the installation.  Certainly, 'import eyeD3' should not create any
errors.

> Then in tag.py, some of the class defs complained about undefined
> variables, for example 'def link(self, f, v = ID3_ANY_VERSION)'
> needed to have quotes around 'ID3_ANY_VERSION'.

That's not what you want to do.  ID3_ANY_VERSION is defined in
eyeD3/__init__.py.  If you quote it, you're breaking it.

> I'm baffled that I'm having to jump through so many hoops because I
> imported eyeD3... is this typical?  What have I done wrong?

That's hard to guess at.  If you can explain what you have done and
how you've installed eyeD3, that would help.

-- 
Todd        OpenPGP -> KeyID: 0xBEAF0CE3 | URL: www.pobox.com/~tmz/pgp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Don't look for me in daylight where robots all assemble.  You'll find
me in my dark world, in my smoke-filled temple.

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From xboxmuncher at gmail.com  Tue Dec 16 07:57:41 2008
From: xboxmuncher at gmail.com (xbmuncher)
Date: Tue, 16 Dec 2008 01:57:41 -0500
Subject: [Tutor] listen in on other program's tcp connections
Message-ID: <df531c470812152257u2bbbf1b1t6dbc5f4185396d44@mail.gmail.com>

On windows XP, I'm running a program that sends TCP connections on port
5039. I'v ran wireshark to determine this. I want to create a simple program
that listens for these connections and intercepts and then turns the data
transferred into a string. From there I'd obviously like my program to act
and manipulate those strings, but for now just spitting out that intercepted
TCP data is good enough.

I was reading up on Twisted. http://twistedmatrix.com/
Can someone get me started on how to do this with twisted framework or
anything else?
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From srilyk at gmail.com  Tue Dec 16 09:55:55 2008
From: srilyk at gmail.com (W W)
Date: Tue, 16 Dec 2008 02:55:55 -0600
Subject: [Tutor] listen in on other program's tcp connections
In-Reply-To: <df531c470812152257u2bbbf1b1t6dbc5f4185396d44@mail.gmail.com>
References: <df531c470812152257u2bbbf1b1t6dbc5f4185396d44@mail.gmail.com>
Message-ID: <333efb450812160055w3cf9a93m764a830037ca664a@mail.gmail.com>

On Tue, Dec 16, 2008 at 12:57 AM, xbmuncher <xboxmuncher at gmail.com> wrote:

> On windows XP, I'm running a program that sends TCP connections on port
> 5039. I'v ran wireshark to determine this. I want to create a simple program
> that listens for these connections and intercepts and then turns the data
> transferred into a string. From there I'd obviously like my program to act
> and manipulate those strings, but for now just spitting out that intercepted
> TCP data is good enough.
>
> I was reading up on Twisted. http://twistedmatrix.com/
> Can someone get me started on how to do this with twisted framework or
> anything else?


I've never done anything like this specifically... but my guess is that it's
pretty similar to creating a proxy.

HTH,
Wayne
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From srilyk at gmail.com  Tue Dec 16 10:20:29 2008
From: srilyk at gmail.com (W W)
Date: Tue, 16 Dec 2008 03:20:29 -0600
Subject: [Tutor] Having Issues with CMD and the 'python' command
In-Reply-To: <ec96e1390812150756l5e720880t2fca05e4b23ffb57@mail.gmail.com>
References: <eb79828c0812150451o3a4ae000i4ff1c70605385216@mail.gmail.com>
	<e1a84d570812150501l68b61bd6v270be05280086ebe@mail.gmail.com>
	<Pine.LNX.4.64.0812150804220.1995@kimball.webabinitio.net>
	<ec96e1390812150756l5e720880t2fca05e4b23ffb57@mail.gmail.com>
Message-ID: <333efb450812160120g57f18631hf6c7149dc307d3@mail.gmail.com>

On Mon, Dec 15, 2008 at 9:56 AM, Benjamin Kaplan
<benjamin.kaplan at case.edu>wrote:

> It's not a question of sensibility. It's a question of purpose. The Zen is
> the philosophy of a language that tries to be easy to learn and easy to use.
> Python is used by programmers who want to experiment with it, but who
> usually know enough not to os.system("rm -r /") or anything similar.
> Windows, on the other hand, wants to hide everything that can potentially
> ruin the system as deep as possible so that many of the idiots who use that
> system don't do stupid things like delete the registry, wipe the environment
> settings, turn off the "Nag Screen" (UAC), and other things of that nature
>

But if it were sensible, it would (like certain other OS's) make it more
difficult to have built-in permissions that allow you to totally hose the
system, i.e. it would be secure.While it may not technically be using the
same comparison criteria we do, Python still gives you the proper result:

In [5]: 'obfuscation' is not 'security' and 'obfuscation' != 'security'
Out[5]: True

I think that's an important concept for programmers to realize. Allowing
people to break things if they fool around enough is not a very sensible, or
secure way of running things. And if you're writing OSes, the sensible thing
is to write secure code. And if you're writing programs for general
consumption, it's /also/ best to write secure code.

That's my 2c anyways :)
-Wayne
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From phpfood at gmail.com  Tue Dec 16 07:55:51 2008
From: phpfood at gmail.com (phpfood)
Date: Tue, 16 Dec 2008 01:55:51 -0500
Subject: [Tutor] listen in on other program's tcp connections
Message-ID: <df531c470812152255w7ef54bfct14c308d02845fd5b@mail.gmail.com>

On windows XP, I'm running a program that sends TCP connections on port
5039. I'v ran wireshark to determine this. I want to create a simple program
that listens for these connections and intercepts and then turns the data
transferred into a string. From there I'd obviously like my program to act
and manipulate those strings, but for now just spitting out that intercepted
TCP data is good enough.

I was reading up on Twisted. http://twistedmatrix.com/
Can someone get me started on how to do this with twisted framework or
anything else?
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From kent37 at tds.net  Tue Dec 16 14:49:52 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 16 Dec 2008 08:49:52 -0500
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<gi6upv$bek$1@ger.gmane.org>
	<40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>
Message-ID: <1c2a2c590812160549t3a19adc7p727e58f1400cd02b@mail.gmail.com>

On Mon, Dec 15, 2008 at 9:33 PM, Marc Tompkins <marc.tompkins at gmail.com> wrote:

> I'm sorry I left it as flat as I did - that Dr. Dobbs article is a
> pretty good explanation, and there's an article somewhere in the
> Effbot bookshelf that does a decent job - but I couldn't find either
> one at that moment.

FWIW my attempt at explaining decorators is here:
http://personalpages.tds.net/~kent37/kk/00001.html

> I've only been using Python for a couple of years now, but my
> experience so far is the same as yours: decorators make my head hurt.
> Even in the Dr. Dobbs article, the examples seem horribly contrived.

It's hard to find a simple example of decorators that is not
contrived. The real-world cases are often too complex for an
introduction. I cite a few examples in my article. Some other
examples:
Django's login_required decorator:
http://docs.djangoproject.com/en/dev/topics/auth/#the-login-required-decorator

In the standard lib, contextlib.contextmanager makes it easy to define
context managers (objects that work with the 'with' statement):
http://docs.python.org/library/contextlib.html#contextlib.contextmanager

and functools.wraps helps to make well-behaved decorators ;-)
http://docs.python.org/library/functools.html#functools.wraps

I told you it was hard to find simple examples!)

Kent

From metolone+gmane at gmail.com  Tue Dec 16 16:39:57 2008
From: metolone+gmane at gmail.com (Mark Tolonen)
Date: Tue, 16 Dec 2008 07:39:57 -0800
Subject: [Tutor] Reading module to import from a string
References: <376fbdcf0812151438w53c8f3f7rc1dc481b524282bc@mail.gmail.com>
Message-ID: <gi8i47$cq$1@ger.gmane.org>


"Shrutarshi Basu" <technorapture at gmail.com> wrote in message 
news:376fbdcf0812151438w53c8f3f7rc1dc481b524282bc at mail.gmail.com...
> Suppose I have a module that I want to import called ImMod1 that's
> saved in a variable like so:
>
> var = "ImMod1"
>
> Is there some way to import ImMod1 by using var?
> Thanks,
> Basu

mod = __import__(var)

-Mark



From iaidas4 at gmail.com  Tue Dec 16 16:53:06 2008
From: iaidas4 at gmail.com (i i)
Date: Tue, 16 Dec 2008 20:53:06 +0500
Subject: [Tutor] (no subject)
Message-ID: <6fb034600812160753s4c1835d6o86f24c22094fb214@mail.gmail.com>

Hi,
     Is their any site where i can find out about custom widget, GtkHTML,
python gtkHtml.




thanx a lot
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From lie.1296 at gmail.com  Tue Dec 16 17:16:46 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Tue, 16 Dec 2008 16:16:46 +0000 (UTC)
Subject: [Tutor] listen in on other program's tcp connections
References: <df531c470812152257u2bbbf1b1t6dbc5f4185396d44@mail.gmail.com>
	<333efb450812160055w3cf9a93m764a830037ca664a@mail.gmail.com>
Message-ID: <gi8k9e$nto$4@ger.gmane.org>

On Tue, 16 Dec 2008 02:55:55 -0600, W W wrote:

> On Tue, Dec 16, 2008 at 12:57 AM, xbmuncher <xboxmuncher at gmail.com>
> wrote:
> 
>> On windows XP, I'm running a program that sends TCP connections on port
>> 5039. I'v ran wireshark to determine this. I want to create a simple
>> program that listens for these connections and intercepts and then
>> turns the data transferred into a string. From there I'd obviously like
>> my program to act and manipulate those strings, but for now just
>> spitting out that intercepted TCP data is good enough.
>>
>> I was reading up on Twisted. http://twistedmatrix.com/ Can someone get
>> me started on how to do this with twisted framework or anything else?
> 
> 
> I've never done anything like this specifically... but my guess is that
> it's pretty similar to creating a proxy.

In the case of proxy, I think the program have to voluntarily send the 
data to the proxy[1]. I think you've got to go round your head around 
wireshark. I don't know wireshark enough to know whether it is possible 
for wireshark to intercept the packet and send it to an external program.

[1] or if you're on windows, you could hack the HOSTS file so data sent  
by the program would instead be redirected to 127.0.0.1 (i.e. localhost, 
i.e. your own computer)


From dineshbvadhia at hotmail.com  Tue Dec 16 17:29:48 2008
From: dineshbvadhia at hotmail.com (Dinesh B Vadhia)
Date: Tue, 16 Dec 2008 08:29:48 -0800
Subject: [Tutor] Fw: Reading gzip files
Message-ID: <COL103-DS3B2BDC1685D994AD73B6EA3F50@phx.gbl>

Hi!  I sent the note below earlier and thank-you for the various responses.  The program reads a bunch of gzip files, writes the content out to a text file line by line (see code below).

What I'd like to do is ... when an "IOError: CRC check failed" error happens then close the offending file and move on to the next file in the list.  How do I achieve this with this particular type of error?

Dinesh




From: Dinesh B Vadhia 
Sent: Sunday, November 30, 2008 2:51 PM
To: tutor at python.org 
Subject: Reading gzip files


I'm reading gzip files and writing the content out to a text file line by line.  The code is simply:

import gzip
list_zipfiles  = dircache.listdir(zipfolder)
writefile = "out_file.txt"
fw = open(writefile, 'w')

for ziparchive in list_zipfiles:
    zfile = gzip.GzipFile(zipfolder + ziparchive, "r")
    for line in zfile:
        fw.write(line)
    zfile.close()
fw.close()

The Traceback is:
Traceback (most recent call last):
  File "....py", line 47, in <module>
    for line in zfile:
  File "C:\Python25\lib\gzip.py", line 444, in next
    line = self.readline()
  File "C:\Python25\lib\gzip.py", line 399, in readline
    c = self.read(readsize)
  File "C:\Python25\lib\gzip.py", line 227, in read
    self._read(readsize)
  File "C:\Python25\lib\gzip.py", line 275, in _read
    self._read_eof()
  File "C:\Python25\lib\gzip.py", line 311, in _read_eof
    raise IOError, "CRC check failed"
IOError: CRC check failed

I've checked the Python docs and online but cannot find a solution to the problem.  Thanks.

Dinesh

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From kent37 at tds.net  Tue Dec 16 17:34:22 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 16 Dec 2008 11:34:22 -0500
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <1c2a2c590812160549t3a19adc7p727e58f1400cd02b@mail.gmail.com>
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<gi6upv$bek$1@ger.gmane.org>
	<40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>
	<1c2a2c590812160549t3a19adc7p727e58f1400cd02b@mail.gmail.com>
Message-ID: <1c2a2c590812160834i17b22a7focabd7a82b849f23@mail.gmail.com>

Here is an interesting example of a decorator that munges the
bytecodes of a function to optimize it:
http://code.activestate.com/recipes/277940/

Kent

From mwalsh at mwalsh.org  Tue Dec 16 17:34:47 2008
From: mwalsh at mwalsh.org (Martin Walsh)
Date: Tue, 16 Dec 2008 10:34:47 -0600
Subject: [Tutor] listen in on other program's tcp connections
In-Reply-To: <df531c470812152255w7ef54bfct14c308d02845fd5b@mail.gmail.com>
References: <df531c470812152255w7ef54bfct14c308d02845fd5b@mail.gmail.com>
Message-ID: <4947D8A7.8080502@mwalsh.org>

phpfood wrote:
> On windows XP, I'm running a program that sends TCP connections on port
> 5039. I'v ran wireshark to determine this. I want to create a simple
> program that listens for these connections and intercepts and then turns
> the data transferred into a string. From there I'd obviously like my
> program to act and manipulate those strings, but for now just spitting
> out that intercepted TCP data is good enough.

IIRC, wireshark uses libpcap for which there are no fewer than two
python extension modules (though, I have not used either):
http://pylibpcap.sourceforge.net/
http://code.google.com/p/pypcap/

Less like a socket proxy, more like packet sniffing.

> 
> I was reading up on Twisted. http://twistedmatrix.com/
> Can someone get me started on how to do this with twisted framework or
> anything else?


From ptmcg at austin.rr.com  Tue Dec 16 17:48:18 2008
From: ptmcg at austin.rr.com (Paul McGuire)
Date: Tue, 16 Dec 2008 10:48:18 -0600
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <mailman.29431.1229444991.3486.tutor@python.org>
References: <mailman.29431.1229444991.3486.tutor@python.org>
Message-ID: <3C9CBC62A6224175BC6F6C59CB42CA00@AWA2>

The Python Wiki has some example decorators at
http://wiki.python.org/moin/PythonDecoratorLibrary.  I think the CGIMethod
wrapper is a good intuitive example, and memoize is a good technique to add
to your Python toolkit.

-- Paul
 


From kent37 at tds.net  Tue Dec 16 18:06:25 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 16 Dec 2008 12:06:25 -0500
Subject: [Tutor] Fw: Reading gzip files
In-Reply-To: <COL103-DS3B2BDC1685D994AD73B6EA3F50@phx.gbl>
References: <COL103-DS3B2BDC1685D994AD73B6EA3F50@phx.gbl>
Message-ID: <1c2a2c590812160906q6e8c652dpbd428ec14be10505@mail.gmail.com>

On Tue, Dec 16, 2008 at 11:29 AM, Dinesh B Vadhia
<dineshbvadhia at hotmail.com> wrote:

> What I'd like to do is ... when an "IOError: CRC check failed" error happens
> then close the offending file and move on to the next file in the list.  How
> do I achieve this with this particular type of error?

You can catch IOError specifically or you can catch all exceptions
using try / except / finally. To trap all exceptions and continue with
the next file:

for ziparchive in list_zipfiles:
    zfile = gzip.GzipFile(zipfolder + ziparchive, "r")
    try:
        for line in zfile:
            fw.write(line)
    except:
        pass
    finally:
        zfile.close()
fw.close()

Kent

From marc.tompkins at gmail.com  Tue Dec 16 18:11:53 2008
From: marc.tompkins at gmail.com (Marc Tompkins)
Date: Tue, 16 Dec 2008 09:11:53 -0800
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <3C9CBC62A6224175BC6F6C59CB42CA00@AWA2>
References: <mailman.29431.1229444991.3486.tutor@python.org>
	<3C9CBC62A6224175BC6F6C59CB42CA00@AWA2>
Message-ID: <40af687b0812160911v36bebe6pe9f6862c90bb0e25@mail.gmail.com>

OK, having looked at
http://wiki.python.org/moin/PythonDecoratorLibrary again with a less
jaundiced eye, I believe my code may soon begin to contain a few of
the dreaded sleepycats...

By the way, (totally off-topic, of course, my apologies): what do all
y'all call the "@" operator?  Here in the States, we call it the
"at-sign", which I find boring; I believe "sleepycat" is a
Scandinavian thing (I picked it up in some long-forgotten article);
some Russians refer to it as ?????? ("sobaka", dog) - again because it
looks like an animal with its tail curled up.

It occurs to me that Pythonistas should have their own name for the
thing.  I propose "ourobouros" - the snake eating its own tail. Of
course, technically that's a capital O, but hey.

-- 
www.fsrtechnologies.com

From alan.gauld at btinternet.com  Tue Dec 16 18:54:05 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 16 Dec 2008 17:54:05 -0000
Subject: [Tutor] what does the "@" operator mean?
References: <mailman.29431.1229444991.3486.tutor@python.org><3C9CBC62A6224175BC6F6C59CB42CA00@AWA2>
	<40af687b0812160911v36bebe6pe9f6862c90bb0e25@mail.gmail.com>
Message-ID: <gi8q01$ug8$1@ger.gmane.org>


"Marc Tompkins" <marc.tompkins at gmail.com> wrote 

> y'all call the "@" operator?  Here in the States, we call it the
> "at-sign", 

Thats what I've always heard in the UK too.

Alan G.


From alan.gauld at btinternet.com  Tue Dec 16 18:56:43 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 16 Dec 2008 17:56:43 -0000
Subject: [Tutor] GtkHTML
References: <6fb034600812160753s4c1835d6o86f24c22094fb214@mail.gmail.com>
Message-ID: <gi8q4v$uv7$1@ger.gmane.org>


"i i" <iaidas4 at gmail.com> wrote in message 
news:6fb034600812160753s4c1835d6o86f24c22094fb214 at mail.gmail.com...
> Hi,
>     Is their any site where i can find out about custom widget, 
> GtkHTML,
> python gtkHtml.

A google search brought up this....

http://www.fcoutant.freesurf.fr/python-gtkhtml.html

Now what do you actually want to know about it?

Alan G 



From gregor.lingl at aon.at  Tue Dec 16 19:19:43 2008
From: gregor.lingl at aon.at (Gregor Lingl)
Date: Tue, 16 Dec 2008 19:19:43 +0100
Subject: [Tutor] TOT: what does the "@" operator mean?
In-Reply-To: <40af687b0812160911v36bebe6pe9f6862c90bb0e25@mail.gmail.com>
References: <mailman.29431.1229444991.3486.tutor@python.org>	<3C9CBC62A6224175BC6F6C59CB42CA00@AWA2>
	<40af687b0812160911v36bebe6pe9f6862c90bb0e25@mail.gmail.com>
Message-ID: <4947F13F.9090104@aon.at>



Marc Tompkins schrieb:
> By the way, (totally off-topic, of course, my apologies): what do all
> y'all call the "@" operator?  Here in the States, we call it the
> "at-sign", which I find boring; I believe "sleepycat" is a
> Scandinavian thing (I picked it up in some long-forgotten article);
> some Russians refer to it as ?????? ("sobaka", dog) - again because it
> looks like an animal with its tail curled up.
>
>   
In German we call it 'Klammeraffe' - which means 'spider monkey':
http://en.wikipedia.org/wiki/Spider_monkey
Don't know why, perhaps also because of it's long tail
Regards,
Gregor

From saluk64007 at gmail.com  Tue Dec 16 19:36:07 2008
From: saluk64007 at gmail.com (Patrick Mullen)
Date: Tue, 16 Dec 2008 10:36:07 -0800
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <gi6upv$bek$1@ger.gmane.org>
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<gi6upv$bek$1@ger.gmane.org>
Message-ID: <c3f69bf60812161036ja32b0a7gd893cb92b38cb949@mail.gmail.com>

On Mon, Dec 15, 2008 at 5:03 PM, Alan Gauld <alan.gauld at btinternet.com> wrote:
>
> "Marc Tompkins" <marc.tompkins at gmail.com> wrote
>
>> If you're just starting out in Python, decorators can be hard to get
>> your head around...
>
> I've been using Python for oover 10 years and still find decorators
> hard to get my head around! :-)
>
> I confess I'm not a fan, they go against the Python spirit of
> explicit is best in my opinion. If I'm calling a function I like to
> know I'm calling a function... I know they make the code look
> pretty but IMHO they are a pain to debug and I'm never totally
> convinced I've got it exactly right.

I thought this way for a while, but I "get" them now.  Mostly I use
them as a shortcut to setting some variables on a function, which
could later be used for introspection.  For instance, a dead simple
test framework I wrote uses decorators like this:

@test("Just load something",removefiles=["sprite1.txt"],teardown=sprite_cleanup)
def load_sprite():
    f = open("sprite1.txt","w")
    f.write("""texture metatex1.png
horizontal 2\nvertical 2\nlength 4\nloops 3""")
    f.close()

The decorator signifies to the testing framework that this function should
be run, the file sprite1.txt should be removed after running the test, and
the function sprite_cleanup should be run as well.  This could have been
done in other ways, but it is a lot more clear with a decorator.
"Hey testing framework, here is how you should run this function"

The actual code for the decorator is not complex either:
def test(t,removefiles=[],teardown=None):
    def dec(f):
        f.a_test = True
        f.test_desc = t
        f.removefiles = removefiles
        f.teardown = teardown
        return f
    return dec

The function in a function is a bit headache inducing, I'll grant that.  But the
dec function just sets some variables on the function.  This could be done
in the old way:

def test(f,t,removefiles=[],teardown=None):
    f.a_test = True
    f.test_desc = t

With the functions decorated like this:
def test_sprites:
    [code]
test(test_sprites,"Just load
something",removefiles=["sprite1.txt"],teardown=sprite_cleanup)

For me though, it is MUCH better to have this information before the
function instead of after.


Another place I am using them is in an interpreter class.  The class
has various methods
tied to different commands that it understands.  I also have a gui
where commands
can be chosen, according to the category of the command.  The
decorator is used to
add some information that the gui can use about the nature of the
command, and which
category it falls under.

I don't used any advanced features of decorators at all, they just
make the code a little
bit more clear and allow me to do a bit more introspection of
functions for various purposes.
I don't use them often, but I do like them.

From sierra_mtnview at sbcglobal.net  Tue Dec 16 19:50:30 2008
From: sierra_mtnview at sbcglobal.net (Wayne Watson)
Date: Tue, 16 Dec 2008 10:50:30 -0800
Subject: [Tutor] WinMerge
Message-ID: <4947F876.4090103@sbcglobal.net>

An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/tutor/attachments/20081216/bb79d504/attachment.htm>

From ptmcg at austin.rr.com  Tue Dec 16 20:24:28 2008
From: ptmcg at austin.rr.com (Paul McGuire)
Date: Tue, 16 Dec 2008 13:24:28 -0600
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <mailman.29451.1229451589.3486.tutor@python.org>
References: <mailman.29451.1229451589.3486.tutor@python.org>
Message-ID: <BC3588131D8E43399548CE99A30DEAEF@AWA2>


> By the way, (totally off-topic, of course, my apologies): what do all
> y'all call the "@" operator?

Back when the "what syntax should we use for decorators?" debate raged, this
symbol was referred to as a "pie", I guess because it looks like the swirl
on top of a cream pie.  I think this term is of Perl/Unix-y origin, similar
to "bang"(!), "splat"(*), and "hash"(#).  

I much prefer the "spidermonkey" or "sleepycat" terms, though.
Unfortunately, here in the US, far fewer would understand what I was saying
than if I called it the prosaic "at-sign" (so named because on old-style
store receipts, one might find "3 apples @ 5 cents", meaning "at the unit
price of" or just "at" for short).

Use of "dot" and "star" for "." and "*" are fairly commonplace now, in place
of their older forms "period" and "asterisk".  Did you ever hear anyone say
"go to 'www period google period com'"?  But it is interesting that the
clunky "ampersand" persists.

Perhaps as we move forward into the unicode world, we will have to have more
names for symbols like "?" and "?".  My Windows character map names these
(when mousing over them) as the "section sign" and "Pilcrow sign".  "@" is
referred to here as the "Commercial At", and "#" as the "Number sign",
although all of us have probably been instructed by voice mail menus to
press the "pound key" when they mean this sign.  Much more good info on all
this trivia at http://en.wikipedia.org/wiki/Punctuation.

-- Paul
Mary love to wear her skates/Upon the ice to frisk/Wasn't she a silly
girl/Her little * ?



From denis.spir at free.fr  Tue Dec 16 20:41:38 2008
From: denis.spir at free.fr (spir)
Date: Tue, 16 Dec 2008 20:41:38 +0100
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<gi6upv$bek$1@ger.gmane.org>
	<40af687b0812151833qe15c6cbu8e344f9acf0ff5dc@mail.gmail.com>
Message-ID: <1229456498.7044.1.camel@o>

I use decorators only to declare class methods.
Denis

Le lundi 15 d?cembre 2008 ? 18:33 -0800, Marc Tompkins a ?crit :

> Does anybody who reads this list use decorators and have a nice word
> to say about them?  I'd be interested to hear it.
> 


From denis.spir at free.fr  Tue Dec 16 21:06:33 2008
From: denis.spir at free.fr (spir)
Date: Tue, 16 Dec 2008 21:06:33 +0100
Subject: [Tutor] reciprocal import
Message-ID: <1229457993.7044.10.camel@o>

Is it legal or possible  at all for two modules to import each other? I
tried several ways and had several kinds of error messages. Usually
"can't import...".

Denis



From steve at alchemy.com  Tue Dec 16 21:08:29 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Tue, 16 Dec 2008 12:08:29 -0800
Subject: [Tutor] reciprocal import
In-Reply-To: <1229457993.7044.10.camel@o>
References: <1229457993.7044.10.camel@o>
Message-ID: <49480ABD.4090500@alchemy.com>

spir wrote:
> Is it legal or possible  at all for two modules to import each other? I
> tried several ways and had several kinds of error messages. Usually
> "can't import...".

My first impression here is that this sounds like a bad class/module 
design if they're really that interdependent.

From kent37 at tds.net  Tue Dec 16 21:38:19 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 16 Dec 2008 15:38:19 -0500
Subject: [Tutor] reciprocal import
In-Reply-To: <1229457993.7044.10.camel@o>
References: <1229457993.7044.10.camel@o>
Message-ID: <1c2a2c590812161238r12af7c26i8d4816c85d9dbc49@mail.gmail.com>

On Tue, Dec 16, 2008 at 3:06 PM, spir <denis.spir at free.fr> wrote:
> Is it legal or possible  at all for two modules to import each other? I
> tried several ways and had several kinds of error messages. Usually
> "can't import...".

It is possible but better to avoid it, perhaps by putting common
functionality into a third module.

The problem is that 'import' is an executable statement and modules
are executed when they are imported. If A.py imports B.py and
vice-versa, then A is not completely defined when B is loaded, and
access to names in A may fail. For example, this will not work:

# A.py
import B

def hello():
    print 'hello'

# B.py
import A
A.hello()


Running A.py will get a NameError in B because A.hello doesn't exist
at the point where B is loaded.

If neither A or B tries to access the contents of the other at load
time you are probably OK, but still it is a bad design and better to
find another solution.

Kent

From christopher.henk at allisontransmission.com  Tue Dec 16 21:42:45 2008
From: christopher.henk at allisontransmission.com (christopher.henk at allisontransmission.com)
Date: Tue, 16 Dec 2008 15:42:45 -0500
Subject: [Tutor] reciprocal import
In-Reply-To: <49480ABD.4090500@alchemy.com>
Message-ID: <OF4401773E.6748B939-ON85257521.00713203-85257521.0071C6F8@gm.com>

Although you generally would want to design so that this does not happen, 
if the import of the first module is only needed in some of the functions 
in the second module, you can include the import within the function 
definition and that would  work ok.
But you can't have the second import at the module level.

Chris




Steve Willoughby <steve at alchemy.com> 
Sent by: tutor-bounces+christopher.henk=allisontransmission.com at python.org
12/16/2008 03:08 PM

To
spir <denis.spir at free.fr>
cc
*tutor <tutor at python.org>
Subject
Re: [Tutor] reciprocal import






spir wrote:
> Is it legal or possible  at all for two modules to import each other? I
> tried several ways and had several kinds of error messages. Usually
> "can't import...".

My first impression here is that this sounds like a bad class/module 
design if they're really that interdependent.
_______________________________________________
Tutor maillist  -  Tutor at python.org
http://mail.python.org/mailman/listinfo/tutor

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From tjampman at gmail.com  Tue Dec 16 22:57:06 2008
From: tjampman at gmail.com (Ole Henning Jensen)
Date: Tue, 16 Dec 2008 22:57:06 +0100
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <40af687b0812160911v36bebe6pe9f6862c90bb0e25@mail.gmail.com>
References: <mailman.29431.1229444991.3486.tutor@python.org>	<3C9CBC62A6224175BC6F6C59CB42CA00@AWA2>
	<40af687b0812160911v36bebe6pe9f6862c90bb0e25@mail.gmail.com>
Message-ID: <49482432.3030104@gmail.com>

Marc Tompkins wrote:
> By the way, (totally off-topic, of course, my apologies): what do all
> y'all call the "@" operator?  Here in the States, we call it the
> "at-sign", which I find boring; I believe "sleepycat" is a
> Scandinavian thing (I picked it up in some long-forgotten article)

Continuing of the OT lane
I'm not sure that "sleepycat" is scandinavien, I'm Danish myself and to 
my knowledge in both Denmark and Sweden the at-sign is called "snabel-a" 
which translates to "trunk-a" (a trunk as on an elefant)
And in Norwegian I belive to be "kr?lle-alfa" translated means "curly-alpha"


From denis.spir at free.fr  Tue Dec 16 23:18:25 2008
From: denis.spir at free.fr (spir)
Date: Tue, 16 Dec 2008 23:18:25 +0100
Subject: [Tutor] reciprocal import
In-Reply-To: <1c2a2c590812161238r12af7c26i8d4816c85d9dbc49@mail.gmail.com>
References: <1229457993.7044.10.camel@o>
	<1c2a2c590812161238r12af7c26i8d4816c85d9dbc49@mail.gmail.com>
Message-ID: <1229465905.8493.9.camel@o>

Steve & Kent:
Actually, I have 2 main modules that work together to achieve the task.
In the first one is defined a set of objects that outline the creation
of objects which classes & subclasses are in the second module. Only for
clarity I need two modules.
A third one copes with exceptions -- so it needs to be referenced in
both other modules. But, in order to provide the user meaning- and
help-ful information, I need to access some elements from the module
that launched the exception.
Actually, the whole of it forms a unity and can be put in a single file
-- but isn't this true for any application?

Denis


Le mardi 16 d?cembre 2008 ? 15:38 -0500, Kent Johnson a ?crit :
> On Tue, Dec 16, 2008 at 3:06 PM, spir <denis.spir at free.fr> wrote:
> > Is it legal or possible  at all for two modules to import each other? I
> > tried several ways and had several kinds of error messages. Usually
> > "can't import...".
> 
> It is possible but better to avoid it, perhaps by putting common
> functionality into a third module.
> 
> The problem is that 'import' is an executable statement and modules
> are executed when they are imported. If A.py imports B.py and
> vice-versa, then A is not completely defined when B is loaded, and
> access to names in A may fail. For example, this will not work:
> 
> # A.py
> import B
> 
> def hello():
>     print 'hello'
> 
> # B.py
> import A
> A.hello()
> 
> 
> Running A.py will get a NameError in B because A.hello doesn't exist
> at the point where B is loaded.
> 
> If neither A or B tries to access the contents of the other at load
> time you are probably OK, but still it is a bad design and better to
> find another solution.
> 
> Kent
> 


From steve at alchemy.com  Tue Dec 16 23:33:39 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Tue, 16 Dec 2008 14:33:39 -0800
Subject: [Tutor] reciprocal import
In-Reply-To: <1229465905.8493.9.camel@o>
References: <1229457993.7044.10.camel@o>	<1c2a2c590812161238r12af7c26i8d4816c85d9dbc49@mail.gmail.com>
	<1229465905.8493.9.camel@o>
Message-ID: <49482CC3.1020108@alchemy.com>

spir wrote:
> Steve & Kent:
> Actually, I have 2 main modules that work together to achieve the task.
> In the first one is defined a set of objects that outline the creation
> of objects which classes & subclasses are in the second module. Only for
> clarity I need two modules.

In my experience (and I realize the limits of speaking in such 
generalities here), every time this situation has come up, refactoring 
the code so this interdependence is resolved has always resulted in a 
clearer, cleaner design.

One module can define a base class, another a derived class (without the 
need for the base class to ever load or be aware of the derived class at 
all), for example.



From alan.gauld at btinternet.com  Wed Dec 17 01:49:47 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 17 Dec 2008 00:49:47 -0000
Subject: [Tutor] reciprocal import
References: <1229457993.7044.10.camel@o><1c2a2c590812161238r12af7c26i8d4816c85d9dbc49@mail.gmail.com>
	<1229465905.8493.9.camel@o>
Message-ID: <gi9ibg$ign$1@ger.gmane.org>


"spir" <denis.spir at free.fr> wrote

> Actually, I have 2 main modules that work together to achieve the 
> task.
> In the first one(A) is defined a set of objects that outline the 
> creation
> of objects which classes & subclasses are in the second module(B).

So far so good. A needs to import B but B does not need to import A.

> A third one(C) copes with exceptions -- so it needs to be referenced 
> in
> both other modules.

Again that's OK, both A and B can import C.

> But, in order to provide the user meaning- and help-ful information,
> I need to access some elements from the module that launched
> the exception.

And this is where the design starts to smell bad.
The exceptions should not need to access the raising class,
the raiser should pass information (perhaps the whole object
via self) into the exception. But exceptions are usually fairly dumb
classes - just transporters of information, it's the handlers where
the intelligence should lie. So how is your exception handling 
working?
It should be in the place where the exception is caught.

> Actually, the whole of it forms a unity and can be put in a single 
> file
> -- but isn't this true for any application?

No, most well designed applications are modular in nature and
chunks can be taken out and reused and other chunks from
other apps inserted without undue disturbance. But that does
require thinking carefully about data flow between modules and
the location of responsibilities for processing that data.

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Wed Dec 17 01:55:54 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 17 Dec 2008 00:55:54 -0000
Subject: [Tutor] what does the "@" operator mean?
References: <mailman.29451.1229451589.3486.tutor@python.org>
	<BC3588131D8E43399548CE99A30DEAEF@AWA2>
Message-ID: <gi9imu$jdg$1@ger.gmane.org>


"Paul McGuire" <ptmcg at austin.rr.com> wrote

> and "#" as the "Number sign", although all of us have probably
> been instructed by voice mail menus to press the "pound key"
> when they mean this sign.

In the UK its usually referred to as hash or square.
When tone dial phones were first introduced in the UK in the late 70's
the official documentation nearly always referred to it as square, but
nowadays hash seems much more common.

( I was recently on an IVR where it started out using hash but then
switched to square for a few options then back to hash again. I 
suspect
I found a route to a relic from the past :-)

Alan G. 



From srilyk at gmail.com  Wed Dec 17 05:54:53 2008
From: srilyk at gmail.com (W W)
Date: Tue, 16 Dec 2008 22:54:53 -0600
Subject: [Tutor] WinMerge
In-Reply-To: <4947F876.4090103@sbcglobal.net>
References: <4947F876.4090103@sbcglobal.net>
Message-ID: <333efb450812162054h2c0c73ccod6ae037d936ff639@mail.gmail.com>

Perhaps bold/italics/underline/strikethrough?
-Wayne

On Tue, Dec 16, 2008 at 12:50 PM, Wayne Watson <sierra_mtnview at sbcglobal.net
> wrote:

>  Is there a way to highlight differences between the two files when
> printing in b/w? Help suggests there may be some texturing, but all I see is
> color choices.
> --
>
>            Wayne Watson (Watson Adventures, Prop., Nevada City, CA)
>
>              (121.01 Deg. W, 39.26 Deg. N) GMT-8 hr std. time)            *         "*Nothing bothers me more than greener-than-thou people
>           who say I don't think we should have nuclear, we should
>           have solar. The fact is that we should go in all of these
>           directions, or we are not going to solve the [energy]
>           problem." -- Dr. Richard Muller, UC Berkeley, physicist
>
> **                    Web Page: <www.speckledwithstars.net/>
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>


-- 
To be considered stupid and to be told so is more painful than being called
gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness,
every vice, has found its defenders, its rhetoric, its ennoblement and
exaltation, but stupidity hasn't. - Primo Levi
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From d.conca at gmail.com  Wed Dec 17 09:27:13 2008
From: d.conca at gmail.com (Daniele)
Date: Wed, 17 Dec 2008 09:27:13 +0100
Subject: [Tutor] what does the "@" operator mean?
Message-ID: <537341c70812170027s2d7c33b8sd96bfedd12071606@mail.gmail.com>

> From: "Alan Gauld" <alan.gauld at btinternet.com>
> Subject: Re: [Tutor] what does the "@" operator mean?

Thinking it's quite funny, I'll keep on with italian words:
the @ is called "chiocciola" which means snail,
while # is called "cancelletto" which is a small gate

As you see italian words are quite close to the sign shape,
like in Denmark i guess (trunk-a for @ is fantastic! :-P )

From sudhir.tact.mca at gmail.com  Wed Dec 17 12:59:31 2008
From: sudhir.tact.mca at gmail.com (Lucky Boy Sudhir)
Date: Wed, 17 Dec 2008 17:29:31 +0530
Subject: [Tutor] Lucky Boy Sudhir has invited you to open a Google mail
	account
Message-ID: <4c0a2dab0812170359y52e56bf1p@mail.gmail.com>

I've been using Gmail and thought you might like to try it out. Here's
an invitation to create an account.

-----------------------------------------------------------------------

Lucky Boy Sudhir  has invited you to open a free Gmail account.

To accept this invitation and register for your account, visit
http://mail.google.com/mail/a-4696b4693-1006ddb730-25c77422c3

Once you create your account, Lucky Boy Sudhir  will be notified with
your new email address so you can stay in touch with Gmail!

If you haven't already heard about Gmail, it's a new search-based webmail
service that offers:

- Over 2,700 megabytes (two gigabytes) of free storage
- Built-in Google search that instantly finds any message you want
- Automatic arrangement of messages and related replies into
  "conversations"
- Powerful spam protection using innovative Google technology
- No large, annoying ads--just small text ads and related pages that are
  relevant to the content of your messages

To learn more about Gmail before registering, visit:
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And, to see how easy it can be to switch to a new email service, check
out our new switch guide: http://mail.google.com/mail/help/switch/

We're still working every day to improve Gmail, so we might ask for your
comments and suggestions periodically.  We hope you'll like Gmail.  We
do.  And, it's only going to get better.

Thanks,

The Gmail Team

(If clicking the URLs in this message does not work, copy and paste them
into the address bar of your browser).

From lie.1296 at gmail.com  Wed Dec 17 14:39:24 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Wed, 17 Dec 2008 13:39:24 +0000 (UTC)
Subject: [Tutor] what does the "@" operator mean?
References: <221405905FE34478B30A32066A739A26@MLKsHP>
	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<gi6upv$bek$1@ger.gmane.org>
Message-ID: <giavec$te8$1@ger.gmane.org>

On Tue, 16 Dec 2008 01:03:55 +0000, Alan Gauld wrote:

> "Marc Tompkins" <marc.tompkins at gmail.com> wrote
> 
>> If you're just starting out in Python, decorators can be hard to get
>> your head around...
> 
> I've been using Python for oover 10 years and still find decorators hard
> to get my head around! :-)
> 
> I confess I'm not a fan, they go against the Python spirit of explicit
> is best in my opinion. If I'm calling a function I like to know I'm
> calling a function... I know they make the code look pretty but IMHO
> they are a pain to debug and I'm never totally convinced I've got it
> exactly right.

I usually think about decorator as a tag or marker instead of function 
calling. When I put the property decorator, I'll be thinking about 
attaching a property tag to the function so the interpreter would handle 
the function as if it is a property. This way, I don't think of it as 
implicit function calling but as an explicit tag (how the tag system 
works is a detail I need not to care).


From sudhir.tact.mca at gmail.com  Wed Dec 17 13:01:31 2008
From: sudhir.tact.mca at gmail.com (Lucky Boy Sudhir)
Date: Wed, 17 Dec 2008 04:01:31 -0800
Subject: [Tutor] Lucky Boy Sudhir wants to chat
Message-ID: <4c0a2dab0812170401ofc80c88x@mail.gmail.com>

-----------------------------------------------------------------------

Lucky Boy Sudhir  wants to stay in better touch using some of Google's
coolest new
products.

If you already have Gmail or Google Talk, visit:
http://mail.google.com/mail/b-4696b4693-d5d69810df-aafd3a6b94976b5f
You'll need to click this link to be able to chat with Lucky Boy Sudhir .

To get Gmail - a free email account from Google with over 2,800 megabytes of
storage - and chat with Lucky Boy Sudhir , visit:
http://mail.google.com/mail/a-4696b4693-d5d69810df-ee3cdf55e5

Gmail offers:
- Instant messaging right inside Gmail
- Powerful spam protection
- Built-in search for finding your messages and a helpful way of organizing
  emails into "conversations"
- No pop-up ads or untargeted banners - just text ads and related information
  that are relevant to the content of your messages

All this, and its yours for free. But wait, there's more! By opening a Gmail
account, you also get access to Google Talk, Google's instant messaging
service:

http://www.google.com/talk/

Google Talk offers:
- Web-based chat that you can use anywhere, without a download
- A contact list that's synchronized with your Gmail account
- Free, high quality PC-to-PC voice calls when you download the Google Talk
  client

Gmail and Google Talk are still in beta. We're working hard to add new features
and make improvements, so we might also ask for your comments and suggestions
periodically. We appreciate your help in making our products even better!

Thanks,
The Google Team

To learn more about Gmail and Google Talk, visit:
http://mail.google.com/mail/help/about.html
http://www.google.com/talk/about.html

(If clicking the URLs in this message does not work, copy and paste them into
the address bar of your browser).

From kent37 at tds.net  Wed Dec 17 15:51:57 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 17 Dec 2008 09:51:57 -0500
Subject: [Tutor] Lucky Boy Sudhir wants to chat
In-Reply-To: <4c0a2dab0812170401ofc80c88x@mail.gmail.com>
References: <4c0a2dab0812170401ofc80c88x@mail.gmail.com>
Message-ID: <1c2a2c590812170651q2466b813waa6b72aa726748e5@mail.gmail.com>

I have unsubscribed Lucky Boy from the list as he is just spamming it.

Kent

On Wed, Dec 17, 2008 at 7:01 AM, Lucky Boy Sudhir
<sudhir.tact.mca at gmail.com> wrote:
> -----------------------------------------------------------------------
>
> Lucky Boy Sudhir  wants to stay in better touch using some of Google's
> coolest new
> products.
>
> If you already have Gmail or Google Talk, visit:
> http://mail.google.com/mail/b-4696b4693-d5d69810df-aafd3a6b94976b5f
> You'll need to click this link to be able to chat with Lucky Boy Sudhir .
>
> To get Gmail - a free email account from Google with over 2,800 megabytes of
> storage - and chat with Lucky Boy Sudhir , visit:
> http://mail.google.com/mail/a-4696b4693-d5d69810df-ee3cdf55e5
>
> Gmail offers:
> - Instant messaging right inside Gmail
> - Powerful spam protection
> - Built-in search for finding your messages and a helpful way of organizing
>  emails into "conversations"
> - No pop-up ads or untargeted banners - just text ads and related information
>  that are relevant to the content of your messages
>
> All this, and its yours for free. But wait, there's more! By opening a Gmail
> account, you also get access to Google Talk, Google's instant messaging
> service:
>
> http://www.google.com/talk/
>
> Google Talk offers:
> - Web-based chat that you can use anywhere, without a download
> - A contact list that's synchronized with your Gmail account
> - Free, high quality PC-to-PC voice calls when you download the Google Talk
>  client
>
> Gmail and Google Talk are still in beta. We're working hard to add new features
> and make improvements, so we might also ask for your comments and suggestions
> periodically. We appreciate your help in making our products even better!
>
> Thanks,
> The Google Team
>
> To learn more about Gmail and Google Talk, visit:
> http://mail.google.com/mail/help/about.html
> http://www.google.com/talk/about.html
>
> (If clicking the URLs in this message does not work, copy and paste them into
> the address bar of your browser).
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

From wolfram.kraus at fen-net.de  Wed Dec 17 16:14:57 2008
From: wolfram.kraus at fen-net.de (Wolfram Kraus)
Date: Wed, 17 Dec 2008 16:14:57 +0100
Subject: [Tutor] what does the "@" operator mean?
In-Reply-To: <gi6upv$bek$1@ger.gmane.org>
References: <221405905FE34478B30A32066A739A26@MLKsHP>	<40af687b0812151242w3efaeee4hf8244a4b632af06f@mail.gmail.com>
	<gi6upv$bek$1@ger.gmane.org>
Message-ID: <gib51h$vcs$1@ger.gmane.org>

Am 16.12.2008 02:03, Alan Gauld schrieb:
> 
> "Marc Tompkins" <marc.tompkins at gmail.com> wrote
> 
>> If you're just starting out in Python, decorators can be hard to get
>> your head around...
> 
> I've been using Python for oover 10 years and still find decorators
> hard to get my head around! :-)
> 
> I confess I'm not a fan, they go against the Python spirit of
> explicit is best in my opinion. If I'm calling a function I like to
> know I'm calling a function... I know they make the code look
> pretty but IMHO they are a pain to debug and I'm never totally
> convinced I've got it exactly right.
> 
> Alan G

Just found this via dzone.org: 
http://gumuz.nl/weblog/simple-python-decorator-classes/

Very interesting read.

HTH,
Wolfram


From simon_ecc at yahoo.co.uk  Wed Dec 17 16:20:17 2008
From: simon_ecc at yahoo.co.uk (ppaarrkk)
Date: Wed, 17 Dec 2008 07:20:17 -0800 (PST)
Subject: [Tutor]  sys.path.append
Message-ID: <21054555.post@talk.nabble.com>


I can do this :

>>> sys.path.append ( 'C:\dump1' )

but not :

>>> x = 'C:\dir1'
>>> sys.path.append(x)

or :


but not :

>>> x = ['C:\dir1']
>>> sys.path.append(x)

Can I append variables to the path, rather than explicit strings ?

-- 
View this message in context: http://www.nabble.com/sys.path.append-tp21054555p21054555.html
Sent from the Python - tutor mailing list archive at Nabble.com.


From kent37 at tds.net  Wed Dec 17 17:17:14 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 17 Dec 2008 11:17:14 -0500
Subject: [Tutor] sys.path.append
In-Reply-To: <21054555.post@talk.nabble.com>
References: <21054555.post@talk.nabble.com>
Message-ID: <1c2a2c590812170817m69c8b22cl8c78068c3a4d1857@mail.gmail.com>

On Wed, Dec 17, 2008 at 10:20 AM, ppaarrkk <simon_ecc at yahoo.co.uk> wrote:
>
> I can do this :
>
>>>> sys.path.append ( 'C:\dump1' )

Note you should use raw strings r'C:\dump1' or double backslash
'C:\\dump1' because the \ is a string escape character.

> but not :
>
>>>> x = 'C:\dir1'
>>>> sys.path.append(x)

That should work fine (other than the single \). What happens when you try it?

> or :

??

> but not :

>>>> x = ['C:\dir1']
>>>> sys.path.append(x)

Here you are appending a list of strings to sys.path, that will not do
what you want.

> Can I append variables to the path, rather than explicit strings ?

Sure.

Kent

From WilliTf at dshs.wa.gov  Wed Dec 17 17:19:07 2008
From: WilliTf at dshs.wa.gov (Williams, Thomas (DSHS/RDA))
Date: Wed, 17 Dec 2008 08:19:07 -0800
Subject: [Tutor] Lucky Boy Sudhir wants to chat
In-Reply-To: <1c2a2c590812170651q2466b813waa6b72aa726748e5@mail.gmail.com>
References: <4c0a2dab0812170401ofc80c88x@mail.gmail.com>
	<1c2a2c590812170651q2466b813waa6b72aa726748e5@mail.gmail.com>
Message-ID: <941871A13165C2418EC144ACB212BDB0CFAB61@dshsmxoly1504g.dshs.wa.lcl>

Thank you

Tom
-----Original Message-----
From: Kent Johnson [mailto:kent37 at tds.net] 
Sent: Wednesday, December 17, 2008 6:52 AM
To: Lucky Boy Sudhir
Cc: tutor at python.org
Subject: Re: [Tutor] Lucky Boy Sudhir wants to chat

I have unsubscribed Lucky Boy from the list as he is just spamming it.

Kent

On Wed, Dec 17, 2008 at 7:01 AM, Lucky Boy Sudhir
<sudhir.tact.mca at gmail.com> wrote:
>
-----------------------------------------------------------------------
>
> Lucky Boy Sudhir  wants to stay in better touch using some of Google's
> coolest new
> products.
>
> If you already have Gmail or Google Talk, visit:
> http://mail.google.com/mail/b-4696b4693-d5d69810df-aafd3a6b94976b5f
> You'll need to click this link to be able to chat with Lucky Boy
Sudhir .
>
> To get Gmail - a free email account from Google with over 2,800
megabytes of
> storage - and chat with Lucky Boy Sudhir , visit:
> http://mail.google.com/mail/a-4696b4693-d5d69810df-ee3cdf55e5
>
> Gmail offers:
> - Instant messaging right inside Gmail
> - Powerful spam protection
> - Built-in search for finding your messages and a helpful way of
organizing
>  emails into "conversations"
> - No pop-up ads or untargeted banners - just text ads and related
information
>  that are relevant to the content of your messages
>
> All this, and its yours for free. But wait, there's more! By opening a
Gmail
> account, you also get access to Google Talk, Google's instant
messaging
> service:
>
> http://www.google.com/talk/
>
> Google Talk offers:
> - Web-based chat that you can use anywhere, without a download
> - A contact list that's synchronized with your Gmail account
> - Free, high quality PC-to-PC voice calls when you download the Google
Talk
>  client
>
> Gmail and Google Talk are still in beta. We're working hard to add new
features
> and make improvements, so we might also ask for your comments and
suggestions
> periodically. We appreciate your help in making our products even
better!
>
> Thanks,
> The Google Team
>
> To learn more about Gmail and Google Talk, visit:
> http://mail.google.com/mail/help/about.html
> http://www.google.com/talk/about.html
>
> (If clicking the URLs in this message does not work, copy and paste
them into
> the address bar of your browser).
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



From david at abbottdavid.com  Thu Dec 18 00:33:00 2008
From: david at abbottdavid.com (David)
Date: Wed, 17 Dec 2008 18:33:00 -0500
Subject: [Tutor] How to exit program without sys.exit()
Message-ID: <49498C2C.2020703@abbottdavid.com>

Hi,
I make these silly programs to learn from examples I find on the list. I 
put a couple together just to practice. I have heard it is not a good 
idea to use sys.exit() but I can not figure out how to do it. Also any 
and all comments are welcome. Thanks

#!/usr/bin/python
import sys
_count = 0

def getinfo():
     answer = yesno("Enter y to continue, n to exit: y/n >> ")
     if answer == "y":
         getnumber()
     else:
         sys.exit()

def counter():
     global _count
     _count += 1
     return _count

def yesno(question):
     responce = None
     while responce not in ("y", "n"):
         responce = raw_input(question).lower()
     return responce

def getnumber():
     try:
         num = int(raw_input("Enter a number between 25 and 75: "))
         if 25 < num < 75:
             print "WOW you are smart ", sayit()
     except ValueError:
         print "Please Enter a number!", getnumber()


def sayit():
     print "Your total correct answers is", counter()
     again()


def again():
     onemore = raw_input("Again? y/n >> " )
     if onemore.lower() == "y":
         getnumber()
     elif onemore.lower() == "n":
         getinfo()
     else:
         sys.exit


def main():
     getinfo()

if __name__=="__main__":
     main()



-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From wescpy at gmail.com  Thu Dec 18 01:54:53 2008
From: wescpy at gmail.com (wesley chun)
Date: Wed, 17 Dec 2008 16:54:53 -0800
Subject: [Tutor] How to exit program without sys.exit()
In-Reply-To: <49498C2C.2020703@abbottdavid.com>
References: <49498C2C.2020703@abbottdavid.com>
Message-ID: <78b3a9580812171654p395c51c1q660c7cdd17092b13@mail.gmail.com>

> I make these silly programs to learn from examples I find on the list. I put
> a couple together just to practice. I have heard it is not a good idea to
> use sys.exit() but I can not figure out how to do it. Also any and all
> comments are welcome. Thanks


david,

welcome to Python!  it's definitely a good thing to read this list and
even more importantly, to practice. as far as your inquiry goes, you
don't need *any* sys.exit() calls in your code. just remove them plus
the else statement above each, as in:

> #!/usr/bin/python
> import sys
> _count = 0
>
> def getinfo():
>    answer = yesno("Enter y to continue, n to exit: y/n >> ")
>    if answer == "y":
>        getnumber()
>
> def counter():
>    global _count
>    _count += 1
>    return _count
>
> def yesno(question):
>    responce = None
>    while responce not in ("y", "n"):
>        responce = raw_input(question).lower()
>    return responce
>
> def getnumber():
>    try:
>        num = int(raw_input("Enter a number between 25 and 75: "))
>        if 25 < num < 75:
>            print "WOW you are smart ", sayit()
>    except ValueError:
>        print "Please Enter a number!", getnumber()
>
>
> def sayit():
>    print "Your total correct answers is", counter()
>    again()
>
>
> def again():
>    onemore = raw_input("Again? y/n >> " )
>    if onemore.lower() == "y":
>        getnumber()
>    elif onemore.lower() == "n":
>        getinfo()
>
> def main():
>    getinfo()
>
> if __name__=="__main__":
>    main()

it should still work the same as before.  your functions will return
to the caller, and they will exit in the same way. finally, when
main() is done, your app is automatically exits.

one other suggestion... you have a lot of functions. it's possible to
reduce the total number, esp. since they're pretty much all one-offs.
generally, you want to employ functions for code that is used more
than once during a single execution of your code.  with your app, you
can probably get away with not having any functions at all.

cheers,
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2007,2001
"Python Fundamentals", Prentice Hall, (c)2009
    http://corepython.com

wesley.j.chun :: wescpy-at-gmail.com
python training and technical consulting
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com

From alan.gauld at btinternet.com  Thu Dec 18 02:26:13 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Thu, 18 Dec 2008 01:26:13 -0000
Subject: [Tutor] How to exit program without sys.exit()
References: <49498C2C.2020703@abbottdavid.com>
Message-ID: <gic8rq$s6j$1@ger.gmane.org>

"David" <david at abbottdavid.com> wrote

> put a couple together just to practice. I have heard it is not a 
> good idea to use sys.exit()

sys.exit is there to exit from a program so there is absolutely 
nothing
wrong with using it. However the way you are using it is not optimal.
A program will terminate or exit by itself if you allow it to "run off 
the end".
So you can remove most of your sys.exit() calls.

Where you want to use sys.exit() is where something happens that
would leave your program running but in a state where it might then do
some damage or produce a wriong result. You can then force a
premature exit with sys.exit. However even in these cases it's often
possible to restructure your code so that an explicit call to sys.exit
is not needed.

So to answer your question, using sys.exit is not bad or wrong,
but mostly you don't need to. It's better to reserve its use for 
occasions
where the program has to be forced to exit early. The other place 
where
you should use sys.exit() is where you want to return a specific error
code to the Operating System - usually for other scripts to use to 
detect
errors by your program.

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From david at abbottdavid.com  Thu Dec 18 04:17:12 2008
From: david at abbottdavid.com (David)
Date: Wed, 17 Dec 2008 22:17:12 -0500
Subject: [Tutor] How to exit program without sys.exit()
In-Reply-To: <78b3a9580812171654p395c51c1q660c7cdd17092b13@mail.gmail.com>
References: <49498C2C.2020703@abbottdavid.com>
	<78b3a9580812171654p395c51c1q660c7cdd17092b13@mail.gmail.com>
Message-ID: <4949C0B8.3010903@abbottdavid.com>

>> one other suggestion... you have a lot of functions. it's possible to
>> reduce the total number, esp. since they're pretty much all one-offs.
>> generally, you want to employ functions for code that is used more
>> than once during a single execution of your code.  with your app, you
>> can probably get away with not having any functions at all.
>> 
>> cheers,
>> -- wesley

I was practicing how to use a global counter and trying to understand 
how functions can interact with each other. I can understand if I can 
see the error's when I run the program. I know my terminology may be 
hard to follow. Also I like your book :)


> So to answer your question, using sys.exit is not bad or wrong,
> but mostly you don't need to. It's better to reserve its use for occasions
> where the program has to be forced to exit early. The other place where
> you should use sys.exit() is where you want to return a specific error
> code to the Operating System - usually for other scripts to use to detect
> errors by your program.
> 
> HTH,
> 
> -- 
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld 

Thanks, That does HAL (help a lot). Also thanks for the tutorial/book I 
have it bookmarked :)

-david


-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From wescpy at gmail.com  Thu Dec 18 06:22:56 2008
From: wescpy at gmail.com (wesley chun)
Date: Wed, 17 Dec 2008 21:22:56 -0800
Subject: [Tutor] How to exit program without sys.exit()
In-Reply-To: <4949C0B8.3010903@abbottdavid.com>
References: <49498C2C.2020703@abbottdavid.com>
	<78b3a9580812171654p395c51c1q660c7cdd17092b13@mail.gmail.com>
	<4949C0B8.3010903@abbottdavid.com>
Message-ID: <78b3a9580812172122l7038ee3ax17b0900becce0ccb@mail.gmail.com>

> I was practicing how to use a global counter and trying to understand
> how functions can interact with each other. I can understand if I can
> see the error's when I run the program. I know my terminology may be
> hard to follow. Also I like your book :)


you are well read since you already have seen places where it is
suggested that using sys.exit() is not the best choice.  as alan has
said, there isn't anything really "evil" about it... it just not
necessary, and you can write applications without using it at all.

another thing you'll read about is how it's "not good" to have global
variables. as with sys.exit() it is possible to have a universal
counter without using a global variable. they are a bit worse than
sys.exit() because they take up extra memory, there is less control --
they can be updated in multiple places in an application; such access
may result in race conditions and unexpected behavior if modified by
concurrent threads, etc.

to find a suitable replacement will depend on what you're counting,
and where a better place may be to store the counter. for example, you
can use a static member of a class, a closure, etc. if you have
specific application requirements, just post them to the list, and
folks will be glad to help you get around using global counters.

glad you enjoy the book! pssst... there is a DVD version of it coming
out at the end of this month called "Python Fundamentals"... keep an
eye out for it! ;-)

best regards,
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2007,2001
"Python Fundamentals", Prentice Hall, (c)2009
    http://corepython.com

wesley.j.chun :: wescpy-at-gmail.com
python training and technical consulting
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com

From gmorris at serif.com  Thu Dec 18 12:41:08 2008
From: gmorris at serif.com (Gareth at Serif)
Date: Thu, 18 Dec 2008 03:41:08 -0800 (PST)
Subject: [Tutor] MP3Info class usage
In-Reply-To: <20081216045037.GA12325@inocybe.teonanacatl.org>
References: <20934673.post@talk.nabble.com>
	<20081210140534.GM13722@inocybe.teonanacatl.org>
	<20980334.post@talk.nabble.com>
	<20081216045037.GA12325@inocybe.teonanacatl.org>
Message-ID: <21071143.post@talk.nabble.com>




Todd Zullinger wrote:
> 
> That's hard to guess at.  If you can explain what you have done and
> how you've installed eyeD3, that would help.
> 

I've not installed it, I've just imported it in my main program.  How do you
install eyeD3, there's no installation package?  I read the readme, which
talks about executing 'configure', but that just reports back that it is not
recognized as an internal or external command, operable program or batch
file.

Clearly I'm missing a huge step, can you help me out?
-- 
View this message in context: http://www.nabble.com/MP3Info-class-usage-tp20934673p21071143.html
Sent from the Python - tutor mailing list archive at Nabble.com.


From tmz at pobox.com  Thu Dec 18 15:51:58 2008
From: tmz at pobox.com (Todd Zullinger)
Date: Thu, 18 Dec 2008 09:51:58 -0500
Subject: [Tutor] MP3Info class usage
In-Reply-To: <21071143.post@talk.nabble.com>
References: <20934673.post@talk.nabble.com>
	<20081210140534.GM13722@inocybe.teonanacatl.org>
	<20980334.post@talk.nabble.com>
	<20081216045037.GA12325@inocybe.teonanacatl.org>
	<21071143.post@talk.nabble.com>
Message-ID: <20081218145157.GO12325@inocybe.teonanacatl.org>

Gareth at Serif wrote:
> I've not installed it, I've just imported it in my main program.
> How do you install eyeD3, there's no installation package?

What OS are you running?  I can help if you run some sort of *nix
system.  If you're on Windows, then I'll have to pass as I know
nothing about installing python modules on Windows. :)

> I read the readme, which talks about executing 'configure', but that
> just reports back that it is not recognized as an internal or
> external command, operable program or batch file.

Hmm, "... batch file" makes me think this is Windows.

On *nix systems, you run ./configure; make; sudo make install.  The ./
in front of configure tells the shell that the program you are trying
to run is in the current directory.  Otherwise, the shell would look
for configure in your $PATH, which does not include the current
directory.

-- 
Todd        OpenPGP -> KeyID: 0xBEAF0CE3 | URL: www.pobox.com/~tmz/pgp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mollison's Bureaucracy Hypothesis:
    If an idea can survive a bureaucratic review and be implemented it
    wasn't worth doing.

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From jbastosneto at gmail.com  Thu Dec 18 17:03:55 2008
From: jbastosneto at gmail.com (Jose Neto)
Date: Thu, 18 Dec 2008 14:03:55 -0200
Subject: [Tutor] PyLucene on Python 2.6
Message-ID: <c3072f110812180803s5a4ca599nd727d6e1cc1c0cfe@mail.gmail.com>

I don't know if it's off-topic or not. If it is, please forgive me and
ignore this question.
Does anyone know if there is a win32 binary of PyLucene? I tried to compile
the sources, but the python "explodes" in the middle of the compilation.

Log file:
$ make
/cygdrive/f/Python26/python.exe -v -m jcc.__main__ --shared  --jar
lucene-java-2
.4.0/build/lucene-core-2.4.0.jar --jar
lucene-java-2.4.0/build/contrib/snowball/
lucene-snowball-2.4.0.jar --jar
lucene-java-2.4.0/build/contrib/highlighter/luce
ne-highlighter-2.4.0.jar --jar
lucene-java-2.4.0/build/contrib/analyzers/lucene-
analyzers-2.4.0.jar --jar
lucene-java-2.4.0/build/contrib/regex/lucene-regex-2.4
.0.jar --jar
lucene-java-2.4.0/build/contrib/queries/lucene-queries-2.4.0.jar --
jar
lucene-java-2.4.0/build/contrib/instantiated/lucene-instantiated-2.4.0.jar -
-jar build/jar/extensions.jar --package java.lang java.lang.System
java.lang.Run
time --package java.util java.text.SimpleDateFormat --package java.io
java.io.St
ringReader java.io.InputStreamReader java.io.FileInputStream --exclude
org.apach
e.lucene.queryParser.Token --exclude
org.apache.lucene.queryParser.TokenMgrError
 --exclude org.apache.lucene.queryParser.QueryParserTokenManager --exclude
org.a
pache.lucene.queryParser.ParseException --python lucene --mapping
org.apache.luc
ene.document.Document 'get:(Ljava/lang/String;)Ljava/lang/String;' --mapping
jav
a.util.Properties 'getProperty:(Ljava/lang/String;)Ljava/lang/String;'
--sequenc
e org.apache.lucene.search.Hits 'length:()I'
'doc:(I)Lorg/apache/lucene/document
/Document;' --version 2.4.0 --files 2 --build
[...]
import zlib # builtin
# f:\Python26\lib\site-packages\jcc-2.1-py2.6-win32.egg\jcc\python.pyc
matches f
:\Python26\lib\site-packages\jcc-2.1-py2.6-win32.egg\jcc\python.py
import jcc.python # precompiled from
f:\Python26\lib\site-packages\jcc-2.1-py2.6
-win32.egg\jcc\python.pyc
# f:\Python26\lib\platform.pyc matches f:\Python26\lib\platform.py
import platform # precompiled from f:\Python26\lib\platform.pyc
# f:\Python26\lib\string.pyc matches f:\Python26\lib\string.py
import string # precompiled from f:\Python26\lib\string.pyc
import strop # builtin
# f:\Python26\lib\py_compile.pyc matches f:\Python26\lib\py_compile.py
import py_compile # precompiled from f:\Python26\lib\py_compile.pyc
import marshal # builtin
# f:\Python26\lib\traceback.pyc matches f:\Python26\lib\traceback.py
import traceback # precompiled from f:\Python26\lib\traceback.pyc
make: *** [compile] Error 255

Regards
Jose
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From andreas at kostyrka.org  Thu Dec 18 18:16:37 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Thu, 18 Dec 2008 18:16:37 +0100
Subject: [Tutor] sys.path.append
In-Reply-To: <1c2a2c590812170817m69c8b22cl8c78068c3a4d1857@mail.gmail.com>
References: <21054555.post@talk.nabble.com>
	<1c2a2c590812170817m69c8b22cl8c78068c3a4d1857@mail.gmail.com>
Message-ID: <20081218181637.18874a8a@andi-lap>

Am Wed, 17 Dec 2008 11:17:14 -0500
schrieb "Kent Johnson" <kent37 at tds.net>:

> On Wed, Dec 17, 2008 at 10:20 AM, ppaarrkk <simon_ecc at yahoo.co.uk>
> wrote:
> >
> > I can do this :
> >
> >>>> sys.path.append ( 'C:\dump1' )
> 
> Note you should use raw strings r'C:\dump1' or double backslash
> 'C:\\dump1' because the \ is a string escape character.
> 
> > but not :
> >
> >>>> x = 'C:\dir1'
> >>>> sys.path.append(x)
> 
> That should work fine (other than the single \). What happens when
> you try it?
> 
> > or :
> 
> ??
> 
> > but not :
> 
> >>>> x = ['C:\dir1']
> >>>> sys.path.append(x)
> 
> Here you are appending a list of strings to sys.path, that will not do
> what you want.

The correct thing to do if you want to add a list of paths to sys.path
(btw, that probably is not what you want in real life, but that's a
complete different question.), you should do 

sys.path.extend(x)

which is an efficient way to do

for i in x:
    sys.path.append(i)

Or to visualize it with something simpler:

a = [1, 2, 3]
b = [4, 5, 6]
c = 7

a # [1,2,3]
a.append(c)
a # [1,2,3,7]
a.append(b)
a # [1,2,3,7,[4,5,6]]
a.extend(b)
a # [1,2,3,7,[4,5,6],4,5,6]

Basically append just appends it's parameter to the list, and if the
parameter happens to be a list, it appends the list as one item. Extend
on the other hand, appends all iterable items in the parameter to the
list.

Andreas

From bgailer at gmail.com  Thu Dec 18 20:31:05 2008
From: bgailer at gmail.com (bob gailer)
Date: Thu, 18 Dec 2008 14:31:05 -0500
Subject: [Tutor] How to exit program without sys.exit()
In-Reply-To: <49498C2C.2020703@abbottdavid.com>
References: <49498C2C.2020703@abbottdavid.com>
Message-ID: <494AA4F9.5080003@gmail.com>

David wrote:
> Hi,
> I make these silly programs to learn from examples I find on the list. 
> I put a couple together just to practice. I have heard it is not a 
> good idea to use sys.exit() but I can not figure out how to do it. 
> Also any and all comments are welcome. Thanks

Others have made valuable comments. I add:

It is better to use a while loop rather than recursive function calls. 
The logic is a lot easier to follow, and you won't run into the 
recursive depth limit. Also restrict try blocks to just the statement 
likely to raise the error you  are expecting.

def getinfo():
    while True:
        answer = yesno("Enter y to continue, n to exit: y/n >> ")
        if answer == "y":
            getnumber()
        else:
           break

def getnumber():
    num = 0
    while True:
        try:
            num = int(raw_input("Enter a number between 25 and 75: "))
        except ValueError:
            print "Please Enter a number!"
        if 25 < num < 75:
            print "WOW you are smart ", sayit()
            break           

There are a lot more recursive calls that I will not try to "fix". I 
hope you get the idea.

In fact I'd start out with no functions at all - just one program in a 
loop. See what you can accomplish that way, then add functions only as 
needed.
>
> #!/usr/bin/python
> import sys
> _count = 0
>
> def getinfo():
>     answer = yesno("Enter y to continue, n to exit: y/n >> ")
>     if answer == "y":
>         getnumber()
>     else:
>         sys.exit()
>
> def counter():
>     global _count
>     _count += 1
>     return _count
>
> def yesno(question):
>     responce = None
>     while responce not in ("y", "n"):
>         responce = raw_input(question).lower()
>     return responce
>
> def getnumber():
>     try:
>         num = int(raw_input("Enter a number between 25 and 75: "))
>         if 25 < num < 75:
>             print "WOW you are smart ", sayit()
>     except ValueError:
>         print "Please Enter a number!", getnumber()
>
>
> def sayit():
>     print "Your total correct answers is", counter()
>     again()
>
>
> def again():
>     onemore = raw_input("Again? y/n >> " )
>     if onemore.lower() == "y":
>         getnumber()
>     elif onemore.lower() == "n":
>         getinfo()
>     else:
>         sys.exit
>
>
> def main():
>     getinfo()
>
> if __name__=="__main__":
>     main()
>
>
>


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From cbc at unc.edu  Thu Dec 18 21:59:15 2008
From: cbc at unc.edu (Chris Calloway)
Date: Thu, 18 Dec 2008 15:59:15 -0500
Subject: [Tutor] PyLucene on Python 2.6
In-Reply-To: <c3072f110812180803s5a4ca599nd727d6e1cc1c0cfe@mail.gmail.com>
References: <c3072f110812180803s5a4ca599nd727d6e1cc1c0cfe@mail.gmail.com>
Message-ID: <494AB9A3.6020001@unc.edu>

On 12/18/2008 11:03 AM, Jose Neto wrote:
> Does anyone know if there is a win32 binary of PyLucene?

http://code.google.com/p/pylucene-win32-binary/downloads/list

-- 
Sincerely,

Chris Calloway
http://www.secoora.org
office: 332 Chapman Hall   phone: (919) 599-3530
mail: Campus Box #3300, UNC-CH, Chapel Hill, NC 27599




From emadnawfal at gmail.com  Fri Dec 19 15:01:24 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Fri, 19 Dec 2008 09:01:24 -0500
Subject: [Tutor] py_compile and chmod +x
Message-ID: <652641e90812190601x2c803cffm7b3ef60457083c98@mail.gmail.com>

Hi Tutors,
#! /usr/bin/env python
print "Hello Tutors"

I have this script saved as hello.py. Why can  I execute it, but not the
compiled version?  or am I doing something wrong? Just curious. Any help
appreciated.
For example :


emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod  +x  hello.py
emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.py
Hello Tutors

Now I compile it in Python:
>>> import py_compile
>>> py_compile.compile("hello.py")
>>>
emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod +x hello.pyc

emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.pyc
: command not found: ?
./hello.pyc: line 2: syntax error near unexpected token `('
./hello.pyc: line 2: `?KIc
@s    dGHd
S(s
                                         Hello
TutorsN((((hello.py<module>s'
emad at emad-laptop:~/Desktop/Programming/Haskell$


-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
--------------------------------------------------------
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From eduardo.susan at gmail.com  Fri Dec 19 16:54:45 2008
From: eduardo.susan at gmail.com (Eduardo Vieira)
Date: Fri, 19 Dec 2008 08:54:45 -0700
Subject: [Tutor] Looping, and Win32com.client
Message-ID: <9356b9f30812190754v356d1a3asa82960981d5f4151@mail.gmail.com>

Hello, this is my first post in this list and I'm not a programmer,
but am enjoying learning python.
I'm trying to make a script to add worksheets to excel files:
I managed to implement this code:

import os
folder = 'C:\\Personal\\oldxlsformat\\'
from win32com.client import Dispatch
xl = Dispatch('Excel.Application')
xl.Application.AskToUpdateLinks = "False"
for ficheiro in os.listdir(folder):
    if ficheiro.endswith('.xls'):
        wb = xl.Workbooks.Open(ficheiro, 2)
        wb.Worksheets.Add().Name = "BVTest"
        wb.Close(SaveChanges = 1)


xl.Quit()

but then I get this error:
Traceback (most recent call last):
  File "C:\Personal\exceltests4.py", line 8, in <module>
    wb = xl.Workbooks.Open(ficheiro, 2)
  File "<COMObject <unknown>>", line 8, in Open
com_error: (-2147352567, 'Exception occurred.', (0, u'Microsoft Office
Excel', u"'AVERY GRAPHICS INK JET.xls' could not be found. Check the
spelling of the file name, and verify that the file location is
correct.\n\nIf you are trying to open the file from your list of most
recently used files, make sure that the file has not been renamed,
moved, or deleted.", u'C:\\Program Files\\Microsoft
Office\\Office12\\1033\\XLMAIN11.CHM', 0, -2146827284), None)

The files I have as a test are these:

C:\Personal\oldxlsformat\AVERY GRAPHICS INK JET.xls
C:\Personal\oldxlsformat\CUTTING MATS & RULERS.xls
C:\Personal\oldxlsformat\Oracal - Ontario Stocking Order.xls
C:\Personal\oldxlsformat\ORACAL 8100-8500.xls

From mail at timgolden.me.uk  Fri Dec 19 16:57:49 2008
From: mail at timgolden.me.uk (Tim Golden)
Date: Fri, 19 Dec 2008 15:57:49 +0000
Subject: [Tutor] Looping, and Win32com.client
In-Reply-To: <9356b9f30812190754v356d1a3asa82960981d5f4151@mail.gmail.com>
References: <9356b9f30812190754v356d1a3asa82960981d5f4151@mail.gmail.com>
Message-ID: <494BC47D.6030002@timgolden.me.uk>

Eduardo Vieira wrote:
> Hello, this is my first post in this list and I'm not a programmer,
> but am enjoying learning python.
> I'm trying to make a script to add worksheets to excel files:
> I managed to implement this code:
> 
> import os
> folder = 'C:\\Personal\\oldxlsformat\\'
> from win32com.client import Dispatch
> xl = Dispatch('Excel.Application')
> xl.Application.AskToUpdateLinks = "False"
> for ficheiro in os.listdir(folder):


os.listdir returns a list of files relative to
the directory in question. (Try it at the
interpreter and see). Excel requires, pretty
much, a list of absolute filenames. So try
using something like os.path.join (folder, ficheiro)
when opening in Excel.

TJG

From eduardo.susan at gmail.com  Fri Dec 19 17:23:53 2008
From: eduardo.susan at gmail.com (Eduardo Vieira)
Date: Fri, 19 Dec 2008 09:23:53 -0700
Subject: [Tutor] Looping, and Win32com.client
In-Reply-To: <494BC47D.6030002@timgolden.me.uk>
References: <9356b9f30812190754v356d1a3asa82960981d5f4151@mail.gmail.com>
	<494BC47D.6030002@timgolden.me.uk>
Message-ID: <9356b9f30812190823x6b279da1xda5ffc950c16520d@mail.gmail.com>

Thank you, now it worked! I made these changes to my code:
for ficheiro in os.listdir(folder):
    file = os.path.join(folder, ficheiro) #added this
    if ficheiro.endswith('.xls'):
        wb = xl.Workbooks.Open(file, 2) # changed this

On Fri, Dec 19, 2008 at 8:57 AM, Tim Golden <mail at timgolden.me.uk> wrote:
> Eduardo Vieira wrote:
>>
>> Hello, this is my first post in this list and I'm not a programmer,
>> but am enjoying learning python.
>> I'm trying to make a script to add worksheets to excel files:
>> I managed to implement this code:
>>
>> import os
>> folder = 'C:\\Personal\\oldxlsformat\\'
>> from win32com.client import Dispatch
>> xl = Dispatch('Excel.Application')
>> xl.Application.AskToUpdateLinks = "False"
>> for ficheiro in os.listdir(folder):
>
>
> os.listdir returns a list of files relative to
> the directory in question. (Try it at the
> interpreter and see). Excel requires, pretty
> much, a list of absolute filenames. So try
> using something like os.path.join (folder, ficheiro)
> when opening in Excel.
>
> TJG
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

From mail at timgolden.me.uk  Fri Dec 19 17:28:15 2008
From: mail at timgolden.me.uk (Tim Golden)
Date: Fri, 19 Dec 2008 16:28:15 +0000
Subject: [Tutor] Looping, and Win32com.client
In-Reply-To: <494BC47D.6030002@timgolden.me.uk>
References: <9356b9f30812190754v356d1a3asa82960981d5f4151@mail.gmail.com>
	<494BC47D.6030002@timgolden.me.uk>
Message-ID: <494BCB9F.8020702@timgolden.me.uk>

Tim Golden wrote:
> Eduardo Vieira wrote:
>> Hello, this is my first post in this list and I'm not a programmer,
>> but am enjoying learning python.
>> I'm trying to make a script to add worksheets to excel files:
>> I managed to implement this code:
>>
>> import os
>> folder = 'C:\\Personal\\oldxlsformat\\'
>> from win32com.client import Dispatch
>> xl = Dispatch('Excel.Application')
>> xl.Application.AskToUpdateLinks = "False"
>> for ficheiro in os.listdir(folder):
> 
> 
> os.listdir returns a list of files relative to
> the directory in question. (Try it at the
> interpreter and see). Excel requires, pretty
> much, a list of absolute filenames.

Of course, I meant this it requires one absolute
filename, not a list :)

TJG

From bgailer at gmail.com  Fri Dec 19 18:12:46 2008
From: bgailer at gmail.com (bob gailer)
Date: Fri, 19 Dec 2008 12:12:46 -0500
Subject: [Tutor] py_compile and chmod +x
In-Reply-To: <652641e90812190601x2c803cffm7b3ef60457083c98@mail.gmail.com>
References: <652641e90812190601x2c803cffm7b3ef60457083c98@mail.gmail.com>
Message-ID: <494BD60E.8000005@gmail.com>

Emad Nawfal (???? ????) wrote:
> Hi Tutors,
> #! /usr/bin/env python
> print "Hello Tutors"
>
> I have this script saved as hello.py. Why can  I execute it, but not 
> the compiled version?  or am I doing something wrong? Just curious. 
> Any help appreciated.

There are 2 issues here.

1 - The shell inspects the first line of the file (#! /usr/bin/env 
python) to find  the program to run
      The compiled file does not have this first line.

2 - The python interpreter expects a script not a compiled program.
      So even if you got the interpreter to run it would try to treat 
the file as a script and bomb anyway.

However when you import hello then it looks first for hello.pyc, and 
runs that. If hello.pyc is missing or older than hello.py it will 
compile hello.py and then run hello.pyc.
> For example :
>
>
> emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod  +x  hello.py
> emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.py
> Hello Tutors
>
> Now I compile it in Python:
> >>> import py_compile
> >>> py_compile.compile("hello.py")
> >>>
> emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod +x hello.pyc
>
> emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.pyc
> : command not found: ?
> ./hello.pyc: line 2: syntax error near unexpected token `('
> ./hello.pyc: line 2: `?KIc
@s    dGHd
S(s
>                                          Hello 
> TutorsN((((hello.py<module>s'
> emad at emad-laptop:~/Desktop/Programming/Haskell$
>
>
> -- 
> ?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? 
> ????????.....???? ???????
> "No victim has ever been more repressed and alienated than the truth"
>
> Emad Soliman Nawfal
> Indiana University, Bloomington
> --------------------------------------------------------
> ------------------------------------------------------------------------
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From andreas at kostyrka.org  Fri Dec 19 18:21:06 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Fri, 19 Dec 2008 18:21:06 +0100
Subject: [Tutor] py_compile and chmod +x
In-Reply-To: <652641e90812190601x2c803cffm7b3ef60457083c98@mail.gmail.com>
References: <652641e90812190601x2c803cffm7b3ef60457083c98@mail.gmail.com>
Message-ID: <20081219182106.13aaf7e8@andi-lap>

Am Fri, 19 Dec 2008 09:01:24 -0500
schrieb "Emad Nawfal (???? ????)" <emadnawfal at gmail.com>:

You are not supposed to compile the main script.

pyc files are automatically generated when you import the py file (but
not execute it), if you are allowed to write them beside the py file.

When a pyc file exists, and it's newer than the py file, python will
import the py file from the pyc file, thus saving on parsing the py
file.

In effect the pyc file is nothing more than a file cache for the parsed
and bytecompiled version of the py file.

Andreas

> Hi Tutors,
> #! /usr/bin/env python
> print "Hello Tutors"
> 
> I have this script saved as hello.py. Why can  I execute it, but not
> the compiled version?  or am I doing something wrong? Just curious.
> Any help appreciated.
> For example :
> 
> 
> emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod  +x  hello.py
> emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.py
> Hello Tutors
> 
> Now I compile it in Python:
> >>> import py_compile
> >>> py_compile.compile("hello.py")
> >>>
> emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod +x hello.pyc
> 
> emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.pyc
> : command not found: ?
> ./hello.pyc: line 2: syntax error near unexpected token `('
> ./hello.pyc: line 2: `?KIc
@s    dGHd
S(s
>                                          Hello
> TutorsN((((hello.py<module>s'
> emad at emad-laptop:~/Desktop/Programming/Haskell$
> 
> 

From andreas at kostyrka.org  Fri Dec 19 18:29:18 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Fri, 19 Dec 2008 18:29:18 +0100
Subject: [Tutor] Looping, and Win32com.client
In-Reply-To: <494BC47D.6030002@timgolden.me.uk>
References: <9356b9f30812190754v356d1a3asa82960981d5f4151@mail.gmail.com>
	<494BC47D.6030002@timgolden.me.uk>
Message-ID: <20081219182918.73af1df1@andi-lap>

Am Fri, 19 Dec 2008 15:57:49 +0000
schrieb Tim Golden <mail at timgolden.me.uk>:

> Eduardo Vieira wrote:
> > Hello, this is my first post in this list and I'm not a programmer,
> > but am enjoying learning python.
> > I'm trying to make a script to add worksheets to excel files:
> > I managed to implement this code:
> > 
> > import os
> > folder = 'C:\\Personal\\oldxlsformat\\'
> > from win32com.client import Dispatch
> > xl = Dispatch('Excel.Application')
> > xl.Application.AskToUpdateLinks = "False"
> > for ficheiro in os.listdir(folder):
> 
> 
> os.listdir returns a list of files relative to
> the directory in question. (Try it at the
> interpreter and see). Excel requires, pretty
> much, a list of absolute filenames. So try
> using something like os.path.join (folder, ficheiro)
> when opening in Excel.

The above should be enough, but if problems persists, it's often
helpful in Win32 OSes to use the 8.3 filename:

shortname = win32api.GetShortPathName(os.path.join(folder, ficheiro))

Another alternative would be to use glob:

import glob

...

for ficheiro in glob.glob(os.path.join(folder, "*.xls")):


glob.glob returns the full path that was found.

Andreas

> 
> TJG
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor

From emadnawfal at gmail.com  Fri Dec 19 18:35:16 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Fri, 19 Dec 2008 12:35:16 -0500
Subject: [Tutor] py_compile and chmod +x
In-Reply-To: <20081219182106.13aaf7e8@andi-lap>
References: <652641e90812190601x2c803cffm7b3ef60457083c98@mail.gmail.com>
	<20081219182106.13aaf7e8@andi-lap>
Message-ID: <652641e90812190935s18ceb6b8v4a349fd92591cc21@mail.gmail.com>

Thank you so much everybody. I was just curious.
This has been very useful.

On Fri, Dec 19, 2008 at 12:21 PM, Andreas Kostyrka <andreas at kostyrka.org>wrote:

> Am Fri, 19 Dec 2008 09:01:24 -0500
> schrieb "Emad Nawfal (???? ????)" <emadnawfal at gmail.com>:
>
> You are not supposed to compile the main script.
>
> pyc files are automatically generated when you import the py file (but
> not execute it), if you are allowed to write them beside the py file.
>
> When a pyc file exists, and it's newer than the py file, python will
> import the py file from the pyc file, thus saving on parsing the py
> file.
>
> In effect the pyc file is nothing more than a file cache for the parsed
> and bytecompiled version of the py file.
>
> Andreas
>
> > Hi Tutors,
> > #! /usr/bin/env python
> > print "Hello Tutors"
> >
> > I have this script saved as hello.py. Why can  I execute it, but not
> > the compiled version?  or am I doing something wrong? Just curious.
> > Any help appreciated.
> > For example :
> >
> >
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod  +x  hello.py
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.py
> > Hello Tutors
> >
> > Now I compile it in Python:
> > >>> import py_compile
> > >>> py_compile.compile("hello.py")
> > >>>
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod +x hello.pyc
> >
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.pyc
> > : command not found: ?
> > ./hello.pyc: line 2: syntax error near unexpected token `('
> > ./hello.pyc: line 2: `?KIc @s    dGHd S( s
> >                                          Hello
> > TutorsN((((hello.py<module> s'
> > emad at emad-laptop:~/Desktop/Programming/Haskell$
> >
> >
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
http://emnawfal.googlepages.com
--------------------------------------------------------
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From emadnawfal at gmail.com  Fri Dec 19 18:36:08 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Fri, 19 Dec 2008 12:36:08 -0500
Subject: [Tutor] py_compile and chmod +x
In-Reply-To: <20081219182106.13aaf7e8@andi-lap>
References: <652641e90812190601x2c803cffm7b3ef60457083c98@mail.gmail.com>
	<20081219182106.13aaf7e8@andi-lap>
Message-ID: <652641e90812190936g6c8ae938o4d925f292860685f@mail.gmail.com>

Thank you so much. This has been very helpful.

On Fri, Dec 19, 2008 at 12:21 PM, Andreas Kostyrka <andreas at kostyrka.org>wrote:

> Am Fri, 19 Dec 2008 09:01:24 -0500
> schrieb "Emad Nawfal (???? ????)" <emadnawfal at gmail.com>:
>
> You are not supposed to compile the main script.
>
> pyc files are automatically generated when you import the py file (but
> not execute it), if you are allowed to write them beside the py file.
>
> When a pyc file exists, and it's newer than the py file, python will
> import the py file from the pyc file, thus saving on parsing the py
> file.
>
> In effect the pyc file is nothing more than a file cache for the parsed
> and bytecompiled version of the py file.
>
> Andreas
>
> > Hi Tutors,
> > #! /usr/bin/env python
> > print "Hello Tutors"
> >
> > I have this script saved as hello.py. Why can  I execute it, but not
> > the compiled version?  or am I doing something wrong? Just curious.
> > Any help appreciated.
> > For example :
> >
> >
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod  +x  hello.py
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.py
> > Hello Tutors
> >
> > Now I compile it in Python:
> > >>> import py_compile
> > >>> py_compile.compile("hello.py")
> > >>>
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ chmod +x hello.pyc
> >
> > emad at emad-laptop:~/Desktop/Programming/Haskell$ ./hello.pyc
> > : command not found: ?
> > ./hello.pyc: line 2: syntax error near unexpected token `('
> > ./hello.pyc: line 2: `?KIc @s    dGHd S( s
> >                                          Hello
> > TutorsN((((hello.py<module> s'
> > emad at emad-laptop:~/Desktop/Programming/Haskell$
> >
> >
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
http://emnawfal.googlepages.com
--------------------------------------------------------
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From carroll at tjc.com  Sat Dec 20 01:25:08 2008
From: carroll at tjc.com (Terry Carroll)
Date: Fri, 19 Dec 2008 16:25:08 -0800 (PST)
Subject: [Tutor] MP3Info class usage
In-Reply-To: <21071143.post@talk.nabble.com>
Message-ID: <Pine.LNX.4.44.0812191617430.16524-100000@violet.rahul.net>

On Thu, 18 Dec 2008, Gareth at Serif wrote:

> I've not installed it, I've just imported it in my main program.  How do you
> install eyeD3, there's no installation package?  I read the readme, which
> talks about executing 'configure', but that just reports back that it is not
> recognized as an internal or external command, operable program or batch
> file.

I'm betting that you'e on windows, like me.

configure is s shell script.  You'll need a version os shell that runs on 
windows.

make, too, I'll bet.

I run Cygwin on windows, which is a pretty good thing to have apart from 
this.  It's free and avaliable from http://www.cygwin.com/

By default, I believe make is not installed; you'll have to request it.

You'll still get the error that "configure" is not recognized as a valid 
command, but invoking it with "sh congigure" works for me.

It would be nice if Eyed3, which is not OS-specific, did not have such an 
OS-specific install process.


From carroll at tjc.com  Sat Dec 20 02:07:29 2008
From: carroll at tjc.com (Terry Carroll)
Date: Fri, 19 Dec 2008 17:07:29 -0800 (PST)
Subject: [Tutor] MP3Info class usage
In-Reply-To: <Pine.LNX.4.44.0812191617430.16524-100000@violet.rahul.net>
Message-ID: <Pine.LNX.4.44.0812191706160.16524-100000@violet.rahul.net>

On Fri, 19 Dec 2008, Terry Carroll wrote:

> configure is s shell script.  You'll need a version os shell that runs on 
> windows. > make, too, I'll bet.
> 
> I run Cygwin on windows, which is a pretty good thing to have apart from 
> this.  It's free and avaliable from http://www.cygwin.com/
...
> It would be nice if Eyed3, which is not OS-specific, did not have such an 
> OS-specific install process.

You know, I just reinstalled Eyed3, and compared the installed result to
the six files distributed in the zipped tarfile, and they're identical
except that one file is named __init__.py.in instead of __init__.py, and
has two doc variables defined with templates.

If you want to avoid having to install a Unix-like environment,
I suggest you just

1) unzip and untar the zipped tarfile,
2) copy the eyeD3 directory from  eyeD3-0.6.16/src/ to Python's
Lib/site-packages/ directory
3) rename __init__.py.in to  __init__.py
4) (probably cosmetic) in __init__.py, edit the lines:

   eyeD3Version = "@PACKAGE_VERSION@";
   eyeD3Maintainer = "@PACKAGE_BUGREPORT@";

to:

   eyeD3Version = "0.6.16";
   eyeD3Maintainer = "Travis Shirk <travis at pobox.com>";

Someone else will now explain why this is a terrible idea.






From Jaggojaggo+Py at gmail.com  Sat Dec 20 17:23:29 2008
From: Jaggojaggo+Py at gmail.com (Omer)
Date: Sat, 20 Dec 2008 18:23:29 +0200
Subject: [Tutor] Class Extend Help
Message-ID: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>

Hey.

I'm trying to do something I think is basic and am failing.

The goal is:
[mimicking the google urlopen syntax]

try:
    from google.appengine.api.urlfetch import fetch
except:
    from urllib import urlopen as fetch


How do I add this "fetch" the property of content?

I basically want fetch(url.com).content to replace urlopen(url.com).read()

Mind, content is not a method.

Thoughts?

Thx. Omer.
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From roadierich at googlemail.com  Sat Dec 20 17:49:24 2008
From: roadierich at googlemail.com (Richard Lovely)
Date: Sat, 20 Dec 2008 16:49:24 +0000
Subject: [Tutor] Class Extend Help
In-Reply-To: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
References: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
Message-ID: <f0b4202b0812200849k3ac5cd97sd45775c3e93ce7db@mail.gmail.com>

There are three ways as I see it: using __getattr__, using a new init,
or using a property decorator.  The last two are probably the most
pythonic, but I'm not familiar with decorators, so here's how I'd do
the second of the three:

try:
     from google.appengine.api.urlfetch import fetch
except:
     from urllib import urlopen

     class fetch(urlopen):
         def __init__(self, *args):
             urlopen.__init__(self, *args)
             self.content = self.read()


This probably doesn't behave exactly the same way as the google class,
but it should be similar enough?
---
Richard "Roadie Rich" Lovely, part of the JNP|UK Famile
www.theJNP.com



2008/12/20 Omer <Jaggojaggo+Py at gmail.com>:
> Hey.
>
> I'm trying to do something I think is basic and am failing.
>
> The goal is:
> [mimicking the google urlopen syntax]
>
> try:
>     from google.appengine.api.urlfetch import fetch
> except:
>     from urllib import urlopen as fetch
>
>
> How do I add this "fetch" the property of content?
>
> I basically want fetch(url.com).content to replace urlopen(url.com).read()
>
> Mind, content is not a method.
>
> Thoughts?
>
> Thx. Omer.
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>

From mwalsh at mwalsh.org  Sat Dec 20 18:35:02 2008
From: mwalsh at mwalsh.org (Martin Walsh)
Date: Sat, 20 Dec 2008 11:35:02 -0600
Subject: [Tutor] Class Extend Help
In-Reply-To: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
References: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
Message-ID: <494D2CC6.1090004@mwalsh.org>

Omer wrote:
> Hey.
> 
> I'm trying to do something I think is basic and am failing.
> 
> The goal is:
> [mimicking the google urlopen syntax]
> 
> try:
>     from google.appengine.api.urlfetch import fetch
> except:
>     from urllib import urlopen as fetch
>    
> 
> How do I add this "fetch" the property of content?

Apparently, the urlfetch.fetch function returns a 'Response' object
which holds the attribute 'content' (among others).
http://code.google.com/appengine/docs/urlfetch/responseobjects.html

So, I suppose it makes sense to do something similar. Here's another
idea (untested):

from urllib2 import urlopen

def fetch(url):
    class Response(object): pass
    response = Response()
    response.content = urlopen('http://www.example.com').read()
    return response

... or if you later want to match the appengine api more closely, then
just add what you need (something like) ...

from urllib2 import urlopen

class Response(object):
    def __init__(self, url):
        response = urlopen(url)
        self.status_code = response.code
        ...
        self.content = response.read()

def fetch(url):
    return Response(url)

HTH,
Marty

From tmz at pobox.com  Sat Dec 20 19:49:31 2008
From: tmz at pobox.com (Todd Zullinger)
Date: Sat, 20 Dec 2008 13:49:31 -0500
Subject: [Tutor] MP3Info class usage
In-Reply-To: <Pine.LNX.4.44.0812191706160.16524-100000@violet.rahul.net>
References: <Pine.LNX.4.44.0812191617430.16524-100000@violet.rahul.net>
	<Pine.LNX.4.44.0812191706160.16524-100000@violet.rahul.net>
Message-ID: <20081220184931.GY12325@inocybe.teonanacatl.org>

Terry Carroll wrote:
> On Fri, 19 Dec 2008, Terry Carroll wrote:
>> It would be nice if Eyed3, which is not OS-specific, did not have
>> such an OS-specific install process.

Perhaps.  But someone who cares about windows support would have to
submit patches.  I don't know if Travis uses windows or not.  I have
submitted a number of patches to eyeD3, but I don't use windows at all
myself.  I can't see spending any time to support a proprietary OS. :)

And, to be fair, the install process isn't really OS-specific.  It
works on a large number of operating systems -- just not on Windows.

> You know, I just reinstalled Eyed3, and compared the installed
> result to the six files distributed in the zipped tarfile, and
> they're identical except that one file is named __init__.py.in
> instead of __init__.py, and has two doc variables defined with
> templates.
> 
> If you want to avoid having to install a Unix-like environment,
> I suggest you just
> 
> 1) unzip and untar the zipped tarfile,
> 2) copy the eyeD3 directory from  eyeD3-0.6.16/src/ to Python's
> Lib/site-packages/ directory
> 3) rename __init__.py.in to  __init__.py
> 4) (probably cosmetic) in __init__.py, edit the lines:
> 
>   eyeD3Version = "@PACKAGE_VERSION@";
>   eyeD3Maintainer = "@PACKAGE_BUGREPORT@";
> 
> to:
> 
>   eyeD3Version = "0.6.16";
>   eyeD3Maintainer = "Travis Shirk <travis at pobox.com>";
> 
> Someone else will now explain why this is a terrible idea.

I don't think it is a bad idea at all.  I was going to suggest
something similar.  If you do that, you should be able to copy the
src/eyeD3 directory somewhere in your PYTHONPATH and use it just fine.

-- 
Todd        OpenPGP -> KeyID: 0xBEAF0CE3 | URL: www.pobox.com/~tmz/pgp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I like this 'God'; he's so deliciously evil.
    -- Stewie Griffin

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From ravikondamuru at gmail.com  Sat Dec 20 20:54:16 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Sat, 20 Dec 2008 11:54:16 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <49427573.5020902@gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
	<49415FDF.3080601@alchemy.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
	<4941E06E.1090608@gmail.com>
	<36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
	<49427573.5020902@gmail.com>
Message-ID: <36601b010812201154m6cfd91f9i5ea7d80bd4f2ef6@mail.gmail.com>

I am trying to use xstruct module to unpack a varaible size record with the
following structure.

struct nameid {
        u32bits len /* total length */
u32bits id;
char name; /* name variable length */
}

As can be seen the length of the name = len - (sizeof(len) + sizeof(id)).

How do  I use xstruct or struct to unpack such a structure?

n = xstruct.structdef(xstruct.little_endian, [
        ('len', (xstruct. unsigned_long, 1)),
        ('id', (xstruct.unsigned_long, 1)),
        ('name', (xstruct.string, <?>)),
])

xstruct seems to expect the exact len to be specified in structdef. Is there
a way to tell it to go till the end of the buffer passed?

thanks,
Ravi.

On Fri, Dec 12, 2008 at 6:30 AM, bob gailer <bgailer at gmail.com> wrote:

> Ravi Kondamuru wrote:
>
>> Denis, These are 32bit, 64bit counters (essentially numbers).
>> Bob, There are well over 10K counters in the log file that are updated
>> every 5 secs. If a counter1's graph was requested, log will have to be
>> parsed once to get the data points. If a user asked for a counter2, now it
>> needs to be retrieved from the log file. Which essentially means having to
>> go through the logfile again. This is because i want to try to avoid using a
>> database to store values after parsing the file.
>>
> Here is a little test program I wrote to check timing on a file of
> *100,000* 64 bit counters.
>
> import time, struct
> ctrs = 100000
> s = time.time()
> # create a file of 800,000 characters (100,000 64 bit numbers)
> f = open('ravi.dat', 'wb')
> for i in range(ctrs):
>  f.write('abcdefgh') # it does not matter what we write as long as it is 8
> bytes.
> print time.time() - s
>
> s = time.time()
> l = []
> # read the file
> f = open('ravi.dat', 'rb').read()
>
> # unpack each 8 characters into an integer and collect in a list
> for b in range(0, ctrs, 8):
>  n = struct.unpack('q', f[b:b+8])
>  l.append(n)
> print time.time() - s
>
> Writing the file took 0.14 seconds on my computer
> Reading and unpacking 0.04 seconds.
> I think you can set performance issues aside.
>
> There is a principle in programming that proposes:
> 1 - get a program running. Preferably in Python as development time is much
> faster.
> 2 - check its performance.
> 3 - refine as needed.
>
>
> --
> Bob Gailer
> Chapel Hill NC 919-636-4239
>
>
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From bill at celestial.net  Sat Dec 20 21:54:21 2008
From: bill at celestial.net (Bill Campbell)
Date: Sat, 20 Dec 2008 12:54:21 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812201154m6cfd91f9i5ea7d80bd4f2ef6@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
	<49415FDF.3080601@alchemy.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
	<4941E06E.1090608@gmail.com>
	<36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
	<49427573.5020902@gmail.com>
	<36601b010812201154m6cfd91f9i5ea7d80bd4f2ef6@mail.gmail.com>
Message-ID: <20081220205421.GB25586@ayn.mi.celestial.com>

On Sat, Dec 20, 2008, Ravi Kondamuru wrote:
>I am trying to use xstruct module to unpack a varaible size record with the
>following structure.
>
>struct nameid {
>        u32bits len /* total length */
>u32bits id;
>char name; /* name variable length */
>}
>
>As can be seen the length of the name = len - (sizeof(len) + sizeof(id)).
>
>How do  I use xstruct or struct to unpack such a structure?
>
>n = xstruct.structdef(xstruct.little_endian, [
>        ('len', (xstruct. unsigned_long, 1)),
>        ('id', (xstruct.unsigned_long, 1)),
>        ('name', (xstruct.string, <?>)),
>])
>
>xstruct seems to expect the exact len to be specified in structdef. Is there
>a way to tell it to go till the end of the buffer passed?

I haven't done this in python yet, but when handling things like
this in C and perl, I have done it with two reads, the first to
get the length, the second to read the data with that length.

Bill
-- 
INTERNET:   bill at celestial.com  Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/  PO Box 820; 6641 E. Mercer Way
Voice:          (206) 236-1676  Mercer Island, WA 98040-0820
Fax:            (206) 232-9186

Independent self-reliant people would be a counterproductive anachronism
in the collective society of the future where people will be defined by
their associations.  1896 John Dewey, educational philosopher, proponent
of modern public schools.

From rellsworthpollard at gmail.com  Sat Dec 20 21:40:03 2008
From: rellsworthpollard at gmail.com (R. Ellsworth Pollard)
Date: Sat, 20 Dec 2008 15:40:03 -0500
Subject: [Tutor] Compiling Python 2.6.1 on Leopard
Message-ID: <d52d80370812201240te2d4abby16a7b7745768bf06@mail.gmail.com>

Where might I find instructions for compiling Python on Leopard?

Robert
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From alan.gauld at btinternet.com  Sun Dec 21 02:00:22 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sun, 21 Dec 2008 01:00:22 -0000
Subject: [Tutor] reading output from a c executable.
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com><36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com><49415B8A.3080701@alchemy.com><36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com><49415FDF.3080601@alchemy.com><36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com><4941E06E.1090608@gmail.com><36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com><49427573.5020902@gmail.com>
	<36601b010812201154m6cfd91f9i5ea7d80bd4f2ef6@mail.gmail.com>
Message-ID: <gik4fe$pf6$1@ger.gmane.org>


"Ravi Kondamuru" <ravikondamuru at gmail.com> wrote

> struct nameid {
>        u32bits len /* total length */
> u32bits id;
> char name; /* name variable length */
> }
>
> As can be seen the length of the name = len - (sizeof(len) + 
> sizeof(id)).
> How do  I use xstruct or struct to unpack such a structure?

I think you will need to read the two fixed length fieldfs then read 
the
name char by char until you hit the null character. After all, thats
what you'd need to do to read it from a file or stream in C too...

Something like:

ltrs = ''
ln = struct.unpack(....)
id = struct.unpack(....)
c = struct.unpack(...)
while c != 0:
    ltrs.append(c)
name = ''.join(ltrs)

You probably could read the two ints and the first char in
one call to struct...

HTH,

Alan G. 



From alan.gauld at btinternet.com  Sun Dec 21 02:07:44 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sun, 21 Dec 2008 01:07:44 -0000
Subject: [Tutor] Compiling Python 2.6.1 on Leopard
References: <d52d80370812201240te2d4abby16a7b7745768bf06@mail.gmail.com>
Message-ID: <gik4t8$qea$1@ger.gmane.org>


"R. Ellsworth Pollard" <rellsworthpollard at gmail.com> wrote in message 
news:d52d80370812201240te2d4abby16a7b7745768bf06 at mail.gmail.com...
> Where might I find instructions for compiling Python on Leopard?

Have you tried the Mac mailing list or the MacPython web site?

I expect the procedure to be the same as for previous versions of
Python on a Mac except you might need to update some of the
compiler libraries etc.

Alan G.
Still on a G3 iBook with Tiger... 



From alan.gauld at btinternet.com  Sun Dec 21 02:05:21 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sun, 21 Dec 2008 01:05:21 -0000
Subject: [Tutor] reading output from a c executable.
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com><36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com><49415B8A.3080701@alchemy.com><36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com><49415FDF.3080601@alchemy.com><36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com><4941E06E.1090608@gmail.com><36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com><49427573.5020902@gmail.com><36601b010812201154m6cfd91f9i5ea7d80bd4f2ef6@mail.gmail.com>
	<20081220205421.GB25586@ayn.mi.celestial.com>
Message-ID: <gik4op$q54$1@ger.gmane.org>


"Bill Campbell" <bill at celestial.net> wrote

>>struct nameid {
>>        u32bits len /* total length */
>>u32bits id;
>>char name; /* name variable length */
>>}
>>
> I haven't done this in python yet, but when handling things like
> this in C and perl, I have done it with two reads, the first to
> get the length, the second to read the data with that length.

Ah yes, I didn't notice that len was the total length of the record,
in that case its much easier. As Bill says you can construct the
struct format string using the calculated length value. Something
like:

fmt = "%dc" % len - (2 * LEN32)
name = struct.unpack(fmt)

You can see a working example of something similar in my
tutor in the handling files topic in the binary files section:

In our case we know it must be like the one we created in 
formatAddress(), namely 'iNs' where N is a variable number. How do we 
determine the value of N?

The struct module provides some helper functions that return the size 
of each data type, so by firing up the Python prompt and experimenting 
we can find out how many bytes of data we will get back for each data 
type:

>>> import struct
>>> print struct.calcsize('i')
4
>>> print struct.calcsize('s')
1
Ok, we know that our data will comprise 4 bytes for the number and one 
byte for each character. So N will be the length of the data minus 4. 
Let's try using that to read our file:

import struct
f = file('address.bin','rb')
data = f.read()
f.close()

fmtString = "i%ds" % (len(data) - 4)
number, rest = struct.unpack(fmtString, data)
address = ' '.join((str(number),rest))

print "Address after restoring data:", addressHTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From kent37 at tds.net  Sun Dec 21 14:41:51 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 21 Dec 2008 08:41:51 -0500
Subject: [Tutor] Compiling Python 2.6.1 on Leopard
In-Reply-To: <d52d80370812201240te2d4abby16a7b7745768bf06@mail.gmail.com>
References: <d52d80370812201240te2d4abby16a7b7745768bf06@mail.gmail.com>
Message-ID: <1c2a2c590812210541x1c1d84ffh9388ac7003b72046@mail.gmail.com>

On Sat, Dec 20, 2008 at 3:40 PM, R. Ellsworth Pollard
<rellsworthpollard at gmail.com> wrote:
> Where might I find instructions for compiling Python on Leopard?

If your goal is just to install Python, there is now a Mac installer available.
http://www.python.org/download/releases/2.6.1/

If you really want to build, download the source and see the
Mac/README file. A basic framework build is
./configure --enable-framework
make
sudo make install

If you want it to work with Tkinter, there is a problem in the
released setup.py, see this bug for a fix:
http://bugs.python.org/issue4017

in particular
http://bugs.python.org/msg74544

Kent

From simon_ecc at yahoo.co.uk  Sun Dec 21 03:02:33 2008
From: simon_ecc at yahoo.co.uk (ppaarrkk)
Date: Sat, 20 Dec 2008 18:02:33 -0800 (PST)
Subject: [Tutor]  Equivalent of grep in python
Message-ID: <21111356.post@talk.nabble.com>


The following works :

file1 = open (file0, "r")

re.findall ( 'some_text', file1.readline() )


But this doesn't :

re.findall ( 'some_text', file1.readlines() )



How do I use grep for a whole text file, not just a single string ?
-- 
View this message in context: http://www.nabble.com/Equivalent-of-grep-in-python-tp21111356p21111356.html
Sent from the Python - tutor mailing list archive at Nabble.com.


From katcipis at inf.ufsc.br  Sun Dec 21 14:57:14 2008
From: katcipis at inf.ufsc.br (Tiago Katcipis)
Date: Sun, 21 Dec 2008 11:57:14 -0200
Subject: [Tutor] Equivalent of grep in python
In-Reply-To: <21111356.post@talk.nabble.com>
References: <21111356.post@talk.nabble.com>
Message-ID: <60a9403b0812210557l3f411cc6m2d11a6386bb39026@mail.gmail.com>

i believe that the following should work

file1 = open(fileO, 'r')
re.findall ('some_text', file1.read())

readlines returns a list with lists inside, where every list is a line of
the text. The read function returns the entire file as one string, so it
should work to what you are wanting to do.

best regards

Katcipis

On Sun, Dec 21, 2008 at 12:02 AM, ppaarrkk <simon_ecc at yahoo.co.uk> wrote:

>
> The following works :
>
> file1 = open (file0, "r")
>
> re.findall ( 'some_text', file1.readline() )
>
>
> But this doesn't :
>
> re.findall ( 'some_text', file1.readlines() )
>
>
>
> How do I use grep for a whole text file, not just a single string ?
> --
> View this message in context:
> http://www.nabble.com/Equivalent-of-grep-in-python-tp21111356p21111356.html
> Sent from the Python - tutor mailing list archive at Nabble.com.
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>



-- 
"it might be a profitable thing to learn Java, but it has no intellectual
value whatsoever" Alexander Stepanov
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From katcipis at inf.ufsc.br  Sun Dec 21 14:58:30 2008
From: katcipis at inf.ufsc.br (Tiago Katcipis)
Date: Sun, 21 Dec 2008 11:58:30 -0200
Subject: [Tutor] Equivalent of grep in python
In-Reply-To: <60a9403b0812210557l3f411cc6m2d11a6386bb39026@mail.gmail.com>
References: <21111356.post@talk.nabble.com>
	<60a9403b0812210557l3f411cc6m2d11a6386bb39026@mail.gmail.com>
Message-ID: <60a9403b0812210558k7d5cf276t799f46576c3bace8@mail.gmail.com>

i forgot, this might help you

http://docs.python.org/tutorial/inputoutput.html#reading-and-writing-files

On Sun, Dec 21, 2008 at 11:57 AM, Tiago Katcipis <katcipis at inf.ufsc.br>wrote:

> i believe that the following should work
>
> file1 = open(fileO, 'r')
> re.findall ('some_text', file1.read())
>
> readlines returns a list with lists inside, where every list is a line of
> the text. The read function returns the entire file as one string, so it
> should work to what you are wanting to do.
>
> best regards
>
> Katcipis
>
>
> On Sun, Dec 21, 2008 at 12:02 AM, ppaarrkk <simon_ecc at yahoo.co.uk> wrote:
>
>>
>> The following works :
>>
>> file1 = open (file0, "r")
>>
>> re.findall ( 'some_text', file1.readline() )
>>
>>
>> But this doesn't :
>>
>> re.findall ( 'some_text', file1.readlines() )
>>
>>
>>
>> How do I use grep for a whole text file, not just a single string ?
>> --
>> View this message in context:
>> http://www.nabble.com/Equivalent-of-grep-in-python-tp21111356p21111356.html
>> Sent from the Python - tutor mailing list archive at Nabble.com.
>>
>> _______________________________________________
>> Tutor maillist  -  Tutor at python.org
>> http://mail.python.org/mailman/listinfo/tutor
>>
>
>
>
> --
> "it might be a profitable thing to learn Java, but it has no intellectual
> value whatsoever" Alexander Stepanov
>



-- 
"it might be a profitable thing to learn Java, but it has no intellectual
value whatsoever" Alexander Stepanov
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From katcipis at inf.ufsc.br  Sun Dec 21 20:14:00 2008
From: katcipis at inf.ufsc.br (Tiago Katcipis)
Date: Sun, 21 Dec 2008 17:14:00 -0200
Subject: [Tutor] Equivalent of grep in python
In-Reply-To: <dfeb4470812211044g669a5dd1s2fb871d0db2627cd@mail.gmail.com>
References: <21111356.post@talk.nabble.com>
	<60a9403b0812210557l3f411cc6m2d11a6386bb39026@mail.gmail.com>
	<60a9403b0812210558k7d5cf276t799f46576c3bace8@mail.gmail.com>
	<dfeb4470812211044g669a5dd1s2fb871d0db2627cd@mail.gmail.com>
Message-ID: <60a9403b0812211114x3132e867j615805c3e9539b48@mail.gmail.com>

Sorry its true, i made a mistake. Readlines is a list with all the lines
inside. I never used readlines (i usually use read), i just read about it on
the tutorial long time ago.

>>> f.readlines()
['This is the first line of the file.\n', 'Second line of the file\n'


Thanks for the help.


On Sun, Dec 21, 2008 at 4:44 PM, Luke Paireepinart
<rabidpoobear at gmail.com>wrote:

> I believe readlines returns a list of strings, not a list of lists.
> You can iterate over the characters in a string if you want, though.
>
> On 12/21/08, Tiago Katcipis <katcipis at inf.ufsc.br> wrote:
> > i forgot, this might help you
> >
> >
> http://docs.python.org/tutorial/inputoutput.html#reading-and-writing-files
> >
> >
> >  On Sun, Dec 21, 2008 at 11:57 AM, Tiago Katcipis <katcipis at inf.ufsc.br>
> > wrote:
> > > i believe that the following should work
> > >
> > > file1 = open(fileO, 'r')
> > > re.findall ('some_text', file1.read())
> > >
> > > readlines returns a list with lists inside, where every list is a line
> of
> > the text. The read function returns the entire file as one string, so it
> > should work to what you are wanting to do.
> > >
> > > best regards
> > >
> > > Katcipis
> > >
> > >
> > >
> > >
> > >
> > > On Sun, Dec 21, 2008 at 12:02 AM, ppaarrkk <simon_ecc at yahoo.co.uk>
> wrote:
> > >
> > > >
> > > > The following works :
> > > >
> > > > file1 = open (file0, "r")
> > > >
> > > > re.findall ( 'some_text', file1.readline() )
> > > >
> > > >
> > > > But this doesn't :
> > > >
> > > > re.findall ( 'some_text', file1.readlines() )
> > > >
> > > >
> > > >
> > > > How do I use grep for a whole text file, not just a single string ?
> > > > --
> > > > View this message in context:
> >
> http://www.nabble.com/Equivalent-of-grep-in-python-tp21111356p21111356.html
> > > > Sent from the Python - tutor mailing list archive at Nabble.com.
> > > >
> > > > _______________________________________________
> > > > Tutor maillist  -  Tutor at python.org
> > > > http://mail.python.org/mailman/listinfo/tutor
> > > >
> > >
> > >
> > >
> > > --
> > > "it might be a profitable thing to learn Java, but it has no
> intellectual
> > value whatsoever" Alexander Stepanov
> > >
> >
> >
> >
> > --
> > "it might be a profitable thing to learn Java, but it has no intellectual
> > value whatsoever" Alexander Stepanov
> >
> > _______________________________________________
> >  Tutor maillist  -  Tutor at python.org
> >  http://mail.python.org/mailman/listinfo/tutor
> >
> >
>



-- 
"it might be a profitable thing to learn Java, but it has no intellectual
value whatsoever" Alexander Stepanov
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From msh at blisses.org  Sun Dec 21 21:31:43 2008
From: msh at blisses.org (Matt Herzog)
Date: Sun, 21 Dec 2008 15:31:43 -0500
Subject: [Tutor] Equivalent of grep in python
Message-ID: <20081221203143.GB20229@chicago.blisses.org>

----- Forwarded message from Tiago Katcipis <katcipis at inf.ufsc.br> -----

i forgot, this might help you

http://docs.python.org/tutorial/inputoutput.html#reading-and-writing-files


I can't help wondering how to do this in python:

	perl -wnl -e '/string/ and print;' filename(s)

Not that I want to forget the precious few bits of Perl I do know, but I'd rather be totally reliant on python for such tasks.


On Sun, Dec 21, 2008 at 11:57 AM, Tiago Katcipis <katcipis at inf.ufsc.br>wrote:

> i believe that the following should work
>
> file1 = open(fileO, 'r')
> re.findall ('some_text', file1.read())
>
> readlines returns a list with lists inside, where every list is a line of
> the text. The read function returns the entire file as one string, so it
> should work to what you are wanting to do.
>
> best regards
>
> Katcipis
>
>
> On Sun, Dec 21, 2008 at 12:02 AM, ppaarrkk <simon_ecc at yahoo.co.uk> wrote:
>
>>
>> The following works :
>>
>> file1 = open (file0, "r")
>>
>> re.findall ( 'some_text', file1.readline() )
>>
>>
>> But this doesn't :
>>
>> re.findall ( 'some_text', file1.readlines() )
>>
>>
>>
>> How do I use grep for a whole text file, not just a single string ?
>> --
>> View this message in context:
>> http://www.nabble.com/Equivalent-of-grep-in-python-tp21111356p21111356.html
>> Sent from the Python - tutor mailing list archive at Nabble.com.
>>
>> _______________________________________________
>> Tutor maillist  -  Tutor at python.org
>> http://mail.python.org/mailman/listinfo/tutor
>>
>
>
>
> --
> "it might be a profitable thing to learn Java, but it has no intellectual
> value whatsoever" Alexander Stepanov
>



-- 
"it might be a profitable thing to learn Java, but it has no intellectual
value whatsoever" Alexander Stepanov

_______________________________________________
Tutor maillist  -  Tutor at python.org
http://mail.python.org/mailman/listinfo/tutor


----- End forwarded message -----

-- 
I fear you speak upon the rack,
Where men enforced do speak anything.

- William Shakespeare

From simon_ecc at yahoo.co.uk  Sun Dec 21 21:00:29 2008
From: simon_ecc at yahoo.co.uk (ppaarrkk)
Date: Sun, 21 Dec 2008 12:00:29 -0800 (PST)
Subject: [Tutor] Equivalent of grep in python
In-Reply-To: <21111356.post@talk.nabble.com>
References: <21111356.post@talk.nabble.com>
Message-ID: <21118578.post@talk.nabble.com>


file1.read() works.


What do I do if I want line numbers ?

I found this code :

http://snippets.dzone.com/posts/show/1638

src = open('2.htm').read()
pattern = '<P>([^<]+)<SUP>'  # or anything else
for m in re.finditer(pattern, src):
       start = m.start()
    	lineno = src.count('\n', 0, start) + 1
    	offset = start - src.rfind('\n', 0, start)
    	word = m.group(1)
    	print "2.htm(%s,%s): %s" % (lineno, offset, word)




Is there not a simpler way than this ?




ppaarrkk wrote:
> 
> The following works :
> 
> file1 = open (file0, "r")
> 
> re.findall ( 'some_text', file1.readline() )
> 
> 
> But this doesn't :
> 
> re.findall ( 'some_text', file1.readlines() )
> 
> 
> 
> How do I use grep for a whole text file, not just a single string ?
> 

-- 
View this message in context: http://www.nabble.com/Equivalent-of-grep-in-python-tp21111356p21118578.html
Sent from the Python - tutor mailing list archive at Nabble.com.


From david at abbottdavid.com  Mon Dec 22 00:51:48 2008
From: david at abbottdavid.com (David)
Date: Sun, 21 Dec 2008 18:51:48 -0500
Subject: [Tutor] subprocess adds %0A to end of string
Message-ID: <494ED694.7010506@abbottdavid.com>

Hi everyone.
Just learning :) I have one program to parse a podcast feed and put it 
into a file.

#!/usr/bin/python
"""Get feed date and link details"""
import feedparser
import sys

def getFeed():
     url = raw_input("Please enter the feed: ")
     data = feedparser.parse(url)
     for entry in data.entries:
         sys.stdout = open("podcast.txt", "a")
         print '%s: %s' % (entry.updated, entry.link)
         sys.stdout.close()
     for entry in data.entries:
         sys.stdout = open("podcast_links.txt", "a")
         print '%s' % (entry.link)
         sys.stdout.close()
getFeed()

next to get the latest item;

#!/usr/bin/python
"""read the last entry and download podcast"""
import subprocess
fname = "podcast.txt"
f = open(fname, 'r')
print "The Latest Podcast", f.readline()
print f.readline()
f.close()
lname = "podcast_links.txt"
L = open(lname, 'r')
print "The Latest Link\n"
download = L.readline()
print download

answer = raw_input("Do you want to download the podcast? ")
if answer == "y":
     wget = "wget"
     subprocess.call([wget, download])
else:
     print "oops"

and here is the output;

david [06:37 PM] opteron ~ $ ./py_read_podcast.py
The Latest Podcast

Sat, 20 Dec 2008 01:52:00 GMT: http://linuxcrazy.com/podcasts/LC-44-arne.mp3

The Latest Link

http://linuxcrazy.com/podcasts/LC-44-arne.mp3

Do you want to download the podcast? y
--2008-12-21 18:38:46--  http://linuxcrazy.com/podcasts/LC-44-arne.mp3%0A
Resolving linuxcrazy.com... 74.220.207.171
Connecting to linuxcrazy.com|74.220.207.171|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2008-12-21 18:38:46 ERROR 404: Not Found.

See how it adds the %0A to the end ?

I am just trying to get it to work, I know it needs a lot of work, error 
checking etc. And I am sure there are better ways, I am new.

thanks
-david


-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From alan.gauld at btinternet.com  Mon Dec 22 01:08:03 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 22 Dec 2008 00:08:03 -0000
Subject: [Tutor] Equivalent of grep in python
References: <20081221203143.GB20229@chicago.blisses.org>
Message-ID: <gimlpb$kf3$1@ger.gmane.org>

"Matt Herzog" <msh at blisses.org> wrote

> I can't help wondering how to do this in python:
> 
> perl -wnl -e '/string/ and print;' filename(s)

The first thing to say is that python is not Perl so there will 
be things Perl does more easily than Python and vice versa. 
(For example Pythons intersactive mode is miles better 
than perls "read from stdin" mode) Perl is better than python 
for quick n dirty one liners, no question. And for every Perl 
one liner there will be a relatively short script that can be 
written. But you will probably be as well using Perl for 
those - its not a bad thing to know and use more than 
one language, quite the opposite.

> Not that I want to forget the precious few bits of Perl I do know, 

> but I'd rather be totally reliant on python for such tasks.

Why? I'd hate to be totally reliant on any one language for anything
Whether it be Python, Lisp, C or assembler!

To answer your question I think the answer to your one liner 
would look something like:

import fileinput   # for iterating over several files

for line in fileinput.input(inplace=1):  # files = argv[1:]
    try: 
        line.replace('string', 'edit')
        print line
    except IOError:
        continue    # ignore bad filenames

This also should help the OP answer his question about how to 
generate filenames, line numbers etc - use fileinput and the 
filename(), filelineno() etc functions...

Not as short as Perl but more maintainable.

If you really must do a one liner its probably possible although 
it will be longer in Python, but I'm not even going to attempt 
it - thats what awk/perl are there for!

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


From david at abbottdavid.com  Mon Dec 22 01:29:23 2008
From: david at abbottdavid.com (David)
Date: Sun, 21 Dec 2008 19:29:23 -0500
Subject: [Tutor] subprocess adds %0A to end of string
In-Reply-To: <494ED694.7010506@abbottdavid.com>
References: <494ED694.7010506@abbottdavid.com>
Message-ID: <494EDF63.4090704@abbottdavid.com>

This seems to work;

download = L.readline()
print download
download = download[0:-1]

What is that last character that is added;
.mp3%0A


-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From kent37 at tds.net  Mon Dec 22 02:19:41 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 21 Dec 2008 20:19:41 -0500
Subject: [Tutor] subprocess adds %0A to end of string
In-Reply-To: <494EDF63.4090704@abbottdavid.com>
References: <494ED694.7010506@abbottdavid.com>
	<494EDF63.4090704@abbottdavid.com>
Message-ID: <1c2a2c590812211719x73afaec1la2a6d49dc312bc81@mail.gmail.com>

On Sun, Dec 21, 2008 at 7:29 PM, David <david at abbottdavid.com> wrote:
> This seems to work;
>
> download = L.readline()
> print download
> download = download[0:-1]
>
> What is that last character that is added;
> .mp3%0A

It is a newline character (line feed). readline() includes the line
endings in the returned lines. Try
download = L.readline().rstrip()

Kent

From mwalsh at mwalsh.org  Mon Dec 22 02:25:52 2008
From: mwalsh at mwalsh.org (Martin Walsh)
Date: Sun, 21 Dec 2008 19:25:52 -0600
Subject: [Tutor] subprocess adds %0A to end of string
In-Reply-To: <494ED694.7010506@abbottdavid.com>
References: <494ED694.7010506@abbottdavid.com>
Message-ID: <494EECA0.8010900@mwalsh.org>

Hi David,

David wrote:
> Hi everyone.
> Just learning :) I have one program to parse a podcast feed and put it
> into a file.

Welcome!

<snip>
> 
> def getFeed():
>     url = raw_input("Please enter the feed: ")
>     data = feedparser.parse(url)
>     for entry in data.entries:
>         sys.stdout = open("podcast.txt", "a")

You should probably try to avoid reassigning sys.stdout. This is usually
a bad idea, and can cause odd behavior that is difficult to
troubleshoot, especially for a beginner. A reasonable approach is to
assign the open file object to a name of your own choosing...

.>>> podcast_file = open('podcast.txt', 'a')

... and then, use the write method of the file object ...

.>>> podcast_file.write('%s: %s' % (entry.updated, entry.link))

More info here:
http://www.python.org/doc/2.5.3/tut/node9.html#SECTION009200000000000000000


>         print '%s: %s' % (entry.updated, entry.link)
>         sys.stdout.close()
>     for entry in data.entries:
>         sys.stdout = open("podcast_links.txt", "a")
>         print '%s' % (entry.link)
>         sys.stdout.close()
> getFeed()
> 
> next to get the latest item;
> 
<snip>
> lname = "podcast_links.txt"
> L = open(lname, 'r')
> print "The Latest Link\n"
> download = L.readline()

The readline method returns a line from the file *including* the newline
 character(s) ('\n').

> print download
> 
> answer = raw_input("Do you want to download the podcast? ")
> if answer == "y":
>     wget = "wget"
>     subprocess.call([wget, download])
> else:
>     print "oops"

OK. There's the problem. Let's assume that after 'download =
L.readline()' that download equals this (you can confirm by adding a
'print repr(download)'):

'http://linuxcrazy.com/podcasts/LC-44-arne.mp3\n'

... then the call becomes (behind the scenes)

subprocess.call(['wget',
        'http://linuxcrazy.com/podcasts/LC-44-arne.mp3\n'])

... so the newline is passed as part of the first argument to the wget
command.

Not so coincidentally, the '%0A' represents a newline ('\n') in a
properly quoted/escaped URL.

.>>> import urllib2
.>>> urllib2.unquote('%0A')
'\n'

I suspect it is the wget command which is quoting the newline, not the
subprocess call, as subprocess doesn't know anything about valid
characters for urls.

You can work around this problem as you already have by dropping the
last character as in 'download[:-1]', or use the strip (or rstrip) str
method:

.>>> download.rstrip()
'http://linuxcrazy.com/podcasts/LC-44-arne.mp3'

More info here: http://www.python.org/doc/2.5.3/lib/string-methods.html

HTH,
Marty

From david at abbottdavid.com  Mon Dec 22 03:18:46 2008
From: david at abbottdavid.com (David)
Date: Sun, 21 Dec 2008 21:18:46 -0500
Subject: [Tutor] subprocess adds %0A to end of string
In-Reply-To: <494EECA0.8010900@mwalsh.org>
References: <494ED694.7010506@abbottdavid.com> <494EECA0.8010900@mwalsh.org>
Message-ID: <494EF906.2040509@abbottdavid.com>

Martin Walsh wrote:

> 
> Welcome!
> 

thanks

> You should probably try to avoid reassigning sys.stdout. This is usually
> a bad idea, and can cause odd behavior that is difficult to
> troubleshoot, especially for a beginner. A reasonable approach is to
> assign the open file object to a name of your own choosing...
> 
> .>>> podcast_file = open('podcast.txt', 'a')
> 
> ... and then, use the write method of the file object ...
> 
> .>>> podcast_file.write('%s: %s' % (entry.updated, entry.link))
> 
> More info here:
> http://www.python.org/doc/2.5.3/tut/node9.html#SECTION009200000000000000000
> 
> 
>>         print '%s: %s' % (entry.updated, entry.link)
>>         sys.stdout.close()
>>     for entry in data.entries:
>>         sys.stdout = open("podcast_links.txt", "a")
>>         print '%s' % (entry.link)
>>         sys.stdout.close()
>> getFeed()
This "podcast_file.write('%s: %s' % (entry.updated, entry.link))"
writes it in one very long string

The Latest Link
http://linuxcrazy.com/podcasts/LC-44-arne.ogghttp://linuxcrazy.com/podcas=>>

and sys.stdout prints to the file one line at a time

How do I split the long string, not even sure if that is the correct term?

for i in somefile: ?

re.somefile(do_something) ?



-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From alan.gauld at btinternet.com  Mon Dec 22 03:38:42 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 22 Dec 2008 02:38:42 -0000
Subject: [Tutor] subprocess adds %0A to end of string
References: <494ED694.7010506@abbottdavid.com> <494EECA0.8010900@mwalsh.org>
	<494EF906.2040509@abbottdavid.com>
Message-ID: <gimujr$6lv$1@ger.gmane.org>


"David" <david at abbottdavid.com> wrote

>>>         sys.stdout = open("podcast_links.txt", "a")
>>>         print '%s' % (entry.link)
>>>         sys.stdout.close()
>>> getFeed()

> This "podcast_file.write('%s: %s' % (entry.updated, entry.link))"
> writes it in one very long string

Use podcastfile.writeline() to write it line by line.

Read any tutorial on file handling to understand how/why these 
various methods work. Get to know files, you'll use them a lot!


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld



From mwalsh at mwalsh.org  Mon Dec 22 06:18:11 2008
From: mwalsh at mwalsh.org (Martin Walsh)
Date: Sun, 21 Dec 2008 23:18:11 -0600
Subject: [Tutor] subprocess adds %0A to end of string
In-Reply-To: <494EF906.2040509@abbottdavid.com>
References: <494ED694.7010506@abbottdavid.com> <494EECA0.8010900@mwalsh.org>
	<494EF906.2040509@abbottdavid.com>
Message-ID: <494F2313.6090807@mwalsh.org>

David wrote:
> Martin Walsh wrote:
> 
>> Welcome!
> 
> thanks

welcome (uh oh, infinite loop warning)

> This "podcast_file.write('%s: %s' % (entry.updated, entry.link))"
> writes it in one very long string

Copy and paste gets me every time. Try this, and note the presence of
the newline ('\n'):

podcast_file.write('%s: %s\n' % (entry.updated, entry.link))

> 
> The Latest Link
> http://linuxcrazy.com/podcasts/LC-44-arne.ogghttp://linuxcrazy.com/podcas=>>
> 
> 
> and sys.stdout prints to the file one line at a time

The primary issue is not that you're writing to sys.stdout, it's that
you're using the print statement which implicitly adds a newline.
Technically you can also do the following (python <= 2.5, and maybe 2.6)
which should demonstrate the concept...

podcastfile = file(somepath, 'a')
print >> podcastfile, '%s: %s' (entry.updated, entry.link)

... however, I would recommend against using the above print statement
syntax for anything other than experimentation because 1) it's not
common practice IMHO, and 2) it's gone starting with python 3.0. 'print'
will be a builtin function instead of a statement going forward.

I second Alan's recommendation to read a tutorial or two to solidify
your understanding of the basic concepts. Alan's tutorial is very good,
and covers everything we have discussed so far, particularly the
"Handling Files" section. Check the link in his email sig.

HTH,
Marty

From jfabiani at yolo.com  Mon Dec 22 16:18:41 2008
From: jfabiani at yolo.com (johnf)
Date: Mon, 22 Dec 2008 07:18:41 -0800
Subject: [Tutor] python parser
Message-ID: <200812220718.41305.jfabiani@yolo.com>

I've been in the programming business for over 20 years and I have never had a 
need for a parser.  But recently I have need to convert code from one 
language to a my new language python.  What a better way to learn the new 
language python than a new project.  I decided it might be time to learn a 
little something about parsers too.  However, I soon discovered that I was 
walking into the world of compiler writers and theories of computer 
scientist.  I paid for and downloaded a paper from O'Reilly books on what I 
thought was going to be on 'pyparser'.  But that turned out to be mostly 
theory.  And nothing about the use of pyparser. 

So I ask you guys is there a link to a practical tutorial that provides hands 
on information on the use of a python parser.  I'd like to see something that 
demo's converting a real language to python.  When I google parsers I have 
found a few simple code examples of parsing a float.  Not really much help (I 
could have done that using Regex) when you want to parse 'if,then' statements 
that can be recursive.

Thanks in advance.  
-- 
John Fabiani

From bryan.fodness at gmail.com  Mon Dec 22 16:45:22 2008
From: bryan.fodness at gmail.com (Bryan Fodness)
Date: Mon, 22 Dec 2008 10:45:22 -0500
Subject: [Tutor] Script to take a screenshot of my website.
Message-ID: <fbf64d2b0812220745m3613285q2edbc468c32863da@mail.gmail.com>

I would like to take a screenshot of my website without opening the browser
or importing extra packages.  Is there a way to do this?
I would like to create a function like screenshot('
http://www.scatterworks.com")

-- 
"The game of science can accurately be described as a never-ending insult to
human intelligence." - Jo?o Magueijo
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From bgailer at gmail.com  Mon Dec 22 18:15:13 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 22 Dec 2008 12:15:13 -0500
Subject: [Tutor] python parser
In-Reply-To: <200812220718.41305.jfabiani@yolo.com>
References: <200812220718.41305.jfabiani@yolo.com>
Message-ID: <494FCB21.606@gmail.com>

johnf wrote:
> I've been in the programming business for over 20 years and I have never had a 
> need for a parser.  But recently I have need to convert code from one 
> language to a my new language python.  

Pray tell: what is the other language, and why do you want to convert 
programs?

I assume you want to convert so you can then modify / extend the old 
programs. If you just plan to run them in Python "as is" I see no value 
in converting!

It is hard to map programs in other languages to Python because Python 
is so different. A direct translation would not take advantage of 
python's uniqueness.


> What a better way to learn the new 
> language python than a new project.  I decided it might be time to learn a 
> little something about parsers too.  However, I soon discovered that I was 
> walking into the world of compiler writers and theories of computer 
> scientist.  I paid for and downloaded a paper from O'Reilly books on what I 
> thought was going to be on 'pyparser'.  But that turned out to be mostly 
> theory.  And nothing about the use of pyparser. 
>
> So I ask you guys is there a link to a practical tutorial that provides hands 
> on information on the use of a python parser.  I'd like to see something that 
> demo's converting a real language to python.  When I google parsers I have 
> found a few simple code examples of parsing a float.  Not really much help (I 
> could have done that using Regex) when you want to parse 'if,then' statements 
> that can be recursive.
>   

FWIW I have written a parser for parts of the CMS Pipelines language. I 
provide a form of BNF for the syntax, generate parsers from that, run a 
"program" through that, which generates lists or dictionaries. I have no 
need to create a program from that.

The Pipelines language is very simple, so I am not dealing with control 
structures, just sequences of words and symbols.


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From mwalsh at mwalsh.org  Mon Dec 22 18:23:55 2008
From: mwalsh at mwalsh.org (Martin Walsh)
Date: Mon, 22 Dec 2008 11:23:55 -0600
Subject: [Tutor] Script to take a screenshot of my website.
In-Reply-To: <fbf64d2b0812220745m3613285q2edbc468c32863da@mail.gmail.com>
References: <fbf64d2b0812220745m3613285q2edbc468c32863da@mail.gmail.com>
Message-ID: <494FCD2B.4090604@mwalsh.org>

Bryan Fodness wrote:
> I would like to take a screenshot of my website without opening the
> browser or importing extra packages.  Is there a way to do this?

Unless you're keen on writing your own html/css/javascript/etc rendering
engine, I'm pretty sure you're going to need extra package(s), or a
browser (even if opened w/o a visible ui).

Perhaps these links will provide inspiration...

http://lapin-blanc.net/09/11/2008/django-website-thumbnail-generator/
http://www.gruppo4.com/~tobia/pythumbnail.shtml

HTH,
Marty

From andreas at kostyrka.org  Mon Dec 22 18:39:01 2008
From: andreas at kostyrka.org (Andreas Kostyrka)
Date: Mon, 22 Dec 2008 18:39:01 +0100
Subject: [Tutor] python parser
In-Reply-To: <200812220718.41305.jfabiani@yolo.com>
References: <200812220718.41305.jfabiani@yolo.com>
Message-ID: <20081222183901.72a31e3f@andi-lap>

Am Mon, 22 Dec 2008 07:18:41 -0800
schrieb johnf <jfabiani at yolo.com>:

> I've been in the programming business for over 20 years and I have
> never had a need for a parser.  But recently I have need to convert
> code from one language to a my new language python.  What a better
> way to learn the new language python than a new project.  I decided
> it might be time to learn a little something about parsers too.
> However, I soon discovered that I was walking into the world of
> compiler writers and theories of computer scientist.  I paid for and
> downloaded a paper from O'Reilly books on what I thought was going to
> be on 'pyparser'.  But that turned out to be mostly theory.  And
> nothing about the use of pyparser. 

Well, scanning and parsing are rather one of the older fields in C.S.

So if I got that correct you want to convert programs from language A
to language Python, and on tops you'll probably want the generated
program to be human-readable and as fast as possible.

Without knowing what A is, it's hard to tell you more, but writing a
parser for almost any programming language is hard, and emitting fast
and human readable code is even harder.

Furthermore, doing it without the theoretical background is not simpler
either.

Btw, possible implementations of a parser depend upon a number of
"theoretical" properties of the grammer you want to implement.

> 
> So I ask you guys is there a link to a practical tutorial that
> provides hands on information on the use of a python parser.  I'd
> like to see something that demo's converting a real language to
> python.  When I google parsers I have found a few simple code
> examples of parsing a float.  Not really much help (I could have done
> that using Regex) when you want to parse 'if,then' statements that
> can be recursive.

Take a look at the examples at the pyparsing website, it even includes
a python parser :)

Andreas
> 
> Thanks in advance.  

From jfabiani at yolo.com  Mon Dec 22 18:39:37 2008
From: jfabiani at yolo.com (johnf)
Date: Mon, 22 Dec 2008 09:39:37 -0800
Subject: [Tutor] python parser
In-Reply-To: <494FCB21.606@gmail.com>
References: <200812220718.41305.jfabiani@yolo.com> <494FCB21.606@gmail.com>
Message-ID: <200812220939.37750.jfabiani@yolo.com>

On Monday 22 December 2008 09:15:13 am bob gailer wrote:
> johnf wrote:
> > I've been in the programming business for over 20 years and I have never
> > had a need for a parser.  But recently I have need to convert code from
> > one language to a my new language python.
>
> Pray tell: what is the other language, and why do you want to convert
> programs?
>
> I assume you want to convert so you can then modify / extend the old
> programs. If you just plan to run them in Python "as is" I see no value
> in converting!
>
> It is hard to map programs in other languages to Python because Python
> is so different. A direct translation would not take advantage of
> python's uniqueness.
>
> > What a better way to learn the new
> > language python than a new project.  I decided it might be time to learn
> > a little something about parsers too.  However, I soon discovered that I
> > was walking into the world of compiler writers and theories of computer
> > scientist.  I paid for and downloaded a paper from O'Reilly books on what
> > I thought was going to be on 'pyparser'.  But that turned out to be
> > mostly theory.  And nothing about the use of pyparser.
> >
> > So I ask you guys is there a link to a practical tutorial that provides
> > hands on information on the use of a python parser.  I'd like to see
> > something that demo's converting a real language to python.  When I
> > google parsers I have found a few simple code examples of parsing a
> > float.  Not really much help (I could have done that using Regex) when
> > you want to parse 'if,then' statements that can be recursive.
>
> FWIW I have written a parser for parts of the CMS Pipelines language. I
> provide a form of BNF for the syntax, generate parsers from that, run a
> "program" through that, which generates lists or dictionaries. I have no
> need to create a program from that.
>
> The Pipelines language is very simple, so I am not dealing with control
> structures, just sequences of words and symbols.

Well I'm attempting to convert VFP and MsSQL (stored procedures and triggers) 
to Python and Postgres (functions and triggers).  Actually, python is very 
close to VFP and I would convert very well.  MsSQL is another question.

It has been suggested that I just read one line at a time and convert.  I 
could do that but I did want to expand my understanding by using a parser. 
And the one line at a time does not lend it self to control structures.  

Even if I do a get the convert to work there would still be a need for hand 
coding.  But it would provide a good start.

So far no links to tutorials?
-- 
John Fabiani

From eduardo.susan at gmail.com  Mon Dec 22 19:33:10 2008
From: eduardo.susan at gmail.com (Eduardo Vieira)
Date: Mon, 22 Dec 2008 11:33:10 -0700
Subject: [Tutor] Very basic question about lists
Message-ID: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>

Hello, I'm trying to teach my self programming with python and there
are some basic things that stumps me:
Given this code:
###
list1 = ['arr', 'bre', 'grau', 'lower', 'tudo']
for item in list1:
    if 'arr' in item:
        print list1
###
The output is (as expected):
['arr', 'bre', 'grau', 'lower', 'tudo']

If I change my condition to:
if 'arr' or 'bell' in item:
or to this:
if 'arr' or 'grau' in item:

I get this result:
['arr', 'bre', 'grau', 'lower', 'tudo']
['arr', 'bre', 'grau', 'lower', 'tudo']
['arr', 'bre', 'grau', 'lower', 'tudo']
['arr', 'bre', 'grau', 'lower', 'tudo']
['arr', 'bre', 'grau', 'lower', 'tudo']

Why this? I guess I'm not grasping the use of AND and OR

Thanks,

Eduardo

From alan.gauld at btinternet.com  Mon Dec 22 19:34:12 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 22 Dec 2008 18:34:12 -0000
Subject: [Tutor] python parser
References: <200812220718.41305.jfabiani@yolo.com>
Message-ID: <giomjd$1t8$1@ger.gmane.org>


"johnf" <jfabiani at yolo.com> wrote

> So I ask you guys is there a link to a practical tutorial that 
> provides hands
> on information on the use of a python parser.

One place to loook for all things to do with processing text is Mertz' 
Text
Processing in Python. He discuissed parsers in some detail although,
infuriatingly, doesn't spend a lot of time on the standard library 
parsers.
But the principles are common and the modules he uses readily 
available.

Its available online at:

http://gnosis.cx/TPiP/

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Mon Dec 22 19:39:53 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 22 Dec 2008 18:39:53 -0000
Subject: [Tutor] Script to take a screenshot of my website.
References: <fbf64d2b0812220745m3613285q2edbc468c32863da@mail.gmail.com>
Message-ID: <giomu2$33p$1@ger.gmane.org>

"Bryan Fodness" <bryan.fodness at gmail.com> wrote

> I would like to take a screenshot of my website without opening the 
> browser

I dont really know what you mean by this? The appearance of a web site
depends on many factors, not least the size of the browser window.
But different browsers render pages differently too - and thats not 
due
to bugs its deliberately included in the concept of HTML. - it is not 
a
page layout language.

Indeed if viewed in a text browser like lynx it will look very 
different!
But even something "standard" like IE looks totally different between 
Mac
and PC versions. And thats without taking account of user preferences
over the colours of hyperlinks, font styles and sizes, security 
settings,
etc etc.

So I'm not sure what you think you could capture without knowing what
computer, OS and browser (and the user settings thereof) was going
to be used...

Alan G. 



From bgailer at gmail.com  Mon Dec 22 19:42:24 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 22 Dec 2008 13:42:24 -0500
Subject: [Tutor] python parser
In-Reply-To: <200812220939.37750.jfabiani@yolo.com>
References: <200812220718.41305.jfabiani@yolo.com> <494FCB21.606@gmail.com>
	<200812220939.37750.jfabiani@yolo.com>
Message-ID: <494FDF90.1040306@gmail.com>

johnf wrote:
> On Monday 22 December 2008 09:15:13 am bob gailer wrote:
>   
>> johnf wrote:
>>     
>>> I've been in the programming business for over 20 years and I have never
>>> had a need for a parser.  But recently I have need to convert code from
>>> one language to a my new language python.
>>>       
>> Pray tell: what is the other language, and why do you want to convert
>> programs?
>>
>> I assume you want to convert so you can then modify / extend the old
>> programs. If you just plan to run them in Python "as is" I see no value
>> in converting!
>>
>> It is hard to map programs in other languages to Python because Python
>> is so different. A direct translation would not take advantage of
>> python's uniqueness.
>>
>>     
>>> What a better way to learn the new
>>> language python than a new project.  I decided it might be time to learn
>>> a little something about parsers too.  However, I soon discovered that I
>>> was walking into the world of compiler writers and theories of computer
>>> scientist.  I paid for and downloaded a paper from O'Reilly books on what
>>> I thought was going to be on 'pyparser'.  But that turned out to be
>>> mostly theory.  And nothing about the use of pyparser.
>>>
>>> So I ask you guys is there a link to a practical tutorial that provides
>>> hands on information on the use of a python parser.  I'd like to see
>>> something that demo's converting a real language to python.  When I
>>> google parsers I have found a few simple code examples of parsing a
>>> float.  Not really much help (I could have done that using Regex) when
>>> you want to parse 'if,then' statements that can be recursive.
>>>       
>> FWIW I have written a parser for parts of the CMS Pipelines language. I
>> provide a form of BNF for the syntax, generate parsers from that, run a
>> "program" through that, which generates lists or dictionaries. I have no
>> need to create a program from that.
>>
>> The Pipelines language is very simple, so I am not dealing with control
>> structures, just sequences of words and symbols.
>>     
>
> Well I'm attempting to convert VFP and MsSQL (stored procedures and triggers) 
> to Python and Postgres (functions and triggers).  Actually, python is very 
> close to VFP and I would convert very well.  MsSQL is another question.
>   

I started writing a VFP - Python converter a few years ago. I will see 
if I have it around.

> It has been suggested that I just read one line at a time and convert.  I 
> could do that but I did want to expand my understanding by using a parser. 
> And the one line at a time does not lend it self to control structures.  
>
> Even if I do a get the convert to work there would still be a need for hand 
> coding.  But it would provide a good start.
>
> So far no links to tutorials?
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From jfabiani at yolo.com  Mon Dec 22 19:42:09 2008
From: jfabiani at yolo.com (johnf)
Date: Mon, 22 Dec 2008 10:42:09 -0800
Subject: [Tutor] python parser
In-Reply-To: <giomjd$1t8$1@ger.gmane.org>
References: <200812220718.41305.jfabiani@yolo.com> <giomjd$1t8$1@ger.gmane.org>
Message-ID: <200812221042.09085.jfabiani@yolo.com>

On Monday 22 December 2008 10:34:12 am Alan Gauld wrote:
> "johnf" <jfabiani at yolo.com> wrote
>
> > So I ask you guys is there a link to a practical tutorial that
> > provides hands
> > on information on the use of a python parser.
>
> One place to loook for all things to do with processing text is Mertz'
> Text
> Processing in Python. He discuissed parsers in some detail although,
> infuriatingly, doesn't spend a lot of time on the standard library
> parsers.
> But the principles are common and the modules he uses readily
> available.
>
> Its available online at:
>
> http://gnosis.cx/TPiP/
>
> HTH,

Interesting - I'll start reading right now.

-- 
John Fabiani

From kent37 at tds.net  Mon Dec 22 19:55:38 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 22 Dec 2008 13:55:38 -0500
Subject: [Tutor] python parser
In-Reply-To: <200812220939.37750.jfabiani@yolo.com>
References: <200812220718.41305.jfabiani@yolo.com> <494FCB21.606@gmail.com>
	<200812220939.37750.jfabiani@yolo.com>
Message-ID: <1c2a2c590812221055u59464978of2ff27ce04691d7e@mail.gmail.com>

On Mon, Dec 22, 2008 at 12:39 PM, johnf <jfabiani at yolo.com> wrote:
> I paid for and downloaded a paper from O'Reilly books on what I
> thought was going to be on 'pyparser'.  But that turned out to be mostly
> theory.  And nothing about the use of pyparser.

Was that "Getting Started with Pyparsing" ? I would be very surprised
if that was all theory, it is written by the author of pyparsing and
he likes examples :-) and the ToC looks like it is mostly extended
examples.

> So far no links to tutorials?

David Mertz has written some columns on parsing, see
http://www.ibm.com/developerworks/views/linux/libraryview.jsp?sort_by=Relevance&show_abstract=true&show_all=false&search_flag=true&topic_by=All+topics+and+related+products&type_by=Articles&search_by=charming+python&Submit.x=0&Submit.y=0

You might also try his book:
http://gnosis.cx/TPiP/

Kent

From bermanrl at cfl.rr.com  Mon Dec 22 20:00:02 2008
From: bermanrl at cfl.rr.com (Robert Berman)
Date: Mon, 22 Dec 2008 14:00:02 -0500
Subject: [Tutor] Very basic question about lists
In-Reply-To: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
Message-ID: <494FE3B2.6070908@cfl.rr.com>

An HTML attachment was scrubbed...
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From ravikondamuru at gmail.com  Mon Dec 22 20:16:11 2008
From: ravikondamuru at gmail.com (Ravi Kondamuru)
Date: Mon, 22 Dec 2008 11:16:11 -0800
Subject: [Tutor] reading output from a c executable.
In-Reply-To: <36601b010812201154m6cfd91f9i5ea7d80bd4f2ef6@mail.gmail.com>
References: <36601b010812111002t3b635c4bsc8c1815af3477618@mail.gmail.com>
	<36601b010812111004x2e390ad3t741c25f2f4b21071@mail.gmail.com>
	<49415B8A.3080701@alchemy.com>
	<36601b010812111035q3039ef62r1d5758c2f2fd7858@mail.gmail.com>
	<49415FDF.3080601@alchemy.com>
	<36601b010812111059k5ac76735r4a1273a4fefeeaaa@mail.gmail.com>
	<4941E06E.1090608@gmail.com>
	<36601b010812120313k6d727537w140316aebb16b843@mail.gmail.com>
	<49427573.5020902@gmail.com>
	<36601b010812201154m6cfd91f9i5ea7d80bd4f2ef6@mail.gmail.com>
Message-ID: <36601b010812221116q64bf8291wfc3cdd7e6689a1a2@mail.gmail.com>

I tried what Bill Campbell suggested: read the len first and then use that
to populate the structdef length field for the string
len = xstruct.structdef(xstruct.little_endian, [
        ('len', (xstruct. unsigned_long, 1)),
])

l = len(buf[0:3])

rec = xstruct.structdef(xstruct.little_endian, [
        ('len', (xstruct. unsigned_long, 1)),
        ('id', (xstruct.unsigned_long, 1)),
        ('name', (xstruct.string, (l.len-8))),
])

n = rec(buf[0:l.len])
print n.len, n.id, n.name

On Sat, Dec 20, 2008 at 11:54 AM, Ravi Kondamuru <ravikondamuru at gmail.com>wrote:

> I am trying to use xstruct module to unpack a varaible size record with the
> following structure.
>
> struct nameid {
>         u32bits len /* total length */
> u32bits id;
>  char name; /* name variable length */
> }
>
> As can be seen the length of the name = len - (sizeof(len) + sizeof(id)).
>
> How do  I use xstruct or struct to unpack such a structure?
>
> n = xstruct.structdef(xstruct.little_endian, [
>         ('len', (xstruct. unsigned_long, 1)),
>         ('id', (xstruct.unsigned_long, 1)),
>         ('name', (xstruct.string, <?>)),
> ])
>
> xstruct seems to expect the exact len to be specified in structdef. Is
> there a way to tell it to go till the end of the buffer passed?
>
> thanks,
> Ravi.
>
> On Fri, Dec 12, 2008 at 6:30 AM, bob gailer <bgailer at gmail.com> wrote:
>
>> Ravi Kondamuru wrote:
>>
>>> Denis, These are 32bit, 64bit counters (essentially numbers).
>>> Bob, There are well over 10K counters in the log file that are updated
>>> every 5 secs. If a counter1's graph was requested, log will have to be
>>> parsed once to get the data points. If a user asked for a counter2, now it
>>> needs to be retrieved from the log file. Which essentially means having to
>>> go through the logfile again. This is because i want to try to avoid using a
>>> database to store values after parsing the file.
>>>
>> Here is a little test program I wrote to check timing on a file of
>> *100,000* 64 bit counters.
>>
>> import time, struct
>> ctrs = 100000
>> s = time.time()
>> # create a file of 800,000 characters (100,000 64 bit numbers)
>> f = open('ravi.dat', 'wb')
>> for i in range(ctrs):
>>  f.write('abcdefgh') # it does not matter what we write as long as it is 8
>> bytes.
>> print time.time() - s
>>
>> s = time.time()
>> l = []
>> # read the file
>> f = open('ravi.dat', 'rb').read()
>>
>> # unpack each 8 characters into an integer and collect in a list
>> for b in range(0, ctrs, 8):
>>  n = struct.unpack('q', f[b:b+8])
>>  l.append(n)
>> print time.time() - s
>>
>> Writing the file took 0.14 seconds on my computer
>> Reading and unpacking 0.04 seconds.
>> I think you can set performance issues aside.
>>
>> There is a principle in programming that proposes:
>> 1 - get a program running. Preferably in Python as development time is
>> much faster.
>> 2 - check its performance.
>> 3 - refine as needed.
>>
>>
>> --
>> Bob Gailer
>> Chapel Hill NC 919-636-4239
>>
>>
>
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From wescpy at gmail.com  Mon Dec 22 20:36:25 2008
From: wescpy at gmail.com (wesley chun)
Date: Mon, 22 Dec 2008 11:36:25 -0800
Subject: [Tutor] Very basic question about lists
In-Reply-To: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
Message-ID: <78b3a9580812221136l251a3556o4403c334982f44d9@mail.gmail.com>

eduardo,

welcome to programming, and even better, welcome to Python!  you've
done your research and found a list of great people who can help you
out.

with regards to your question, my comment are below...

> list1 = ['arr', 'bre', 'grau', 'lower', 'tudo']
> for item in list1:
>    if 'arr' in item:
>        print list1
> ###
> The output is (as expected):
> ['arr', 'bre', 'grau', 'lower', 'tudo']

you need to question your output here. sure it is what you *want*, but
i don't think you got it the way you originally thought.

what are you trying to do? are you trying to see whether the string
'arr' is in the entire list, or are you comparing one element at a
time and checking if a string is found in a larger string? (your code
is doing the latter.) here is some code (and output) which will
hopefully make it clear:

>>> list1 = ['arr', 'bre', 'grau', 'lower', 'tudo']
>>> 'arr' in list1
True
>>> 'bell' in list1
False
>>> 'grau' in list1
True

the "in" operator checks if an entire string is in a list or not. you
do not have to loop through it to get an answer. now let's iterate
through each string.

>>> for item in list1:
...     print item
...
arr
bre
grau
lower
tudo

notice that item represents each string in the list in each iteration
of the loop. if you are asking whether 'arr' is in item, you are
asking if 'arr' is in 'arr', 'arr' is in 'bre', 'arr' is in 'grau',
etc., so your (single) output is due to the fact that on the first
pass, 'arr' is in 'arr'. in other words, you did this:

>> tmp = 'arr'
>>> 'arr' in tmp
True
>>> 'arr' in 'arr'
True

so that's why your list printed out, because 'arr' in 'arr' returned
True. so, to really illustrate what you're doing, take a look at this
example:

>>> for item in list1:
...     if 'owe' in item:
...         print list1
...
['arr', 'bre', 'grau', 'lower', 'tudo']

this time, the output *is* expected, because 'owe' is *in* one of the
5 strings in your list... in particular, 'owe' is in 'lower', so
again, this is why list1 is printed, because that statement is True.


> Why this? I guess I'm not grasping the use of AND and OR

i don't think you have a problem with AND and OR... i think your
problem was with IN instead. :-) remember, for strings, IN means
whether a substring is found in a larger string (or not), and for
lists, IN means whether an object is found in the list (or not).

hope this helps!
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2007,2001
"Python Fundamentals", Prentice Hall, (c)2009
    http://corepython.com

wesley.j.chun :: wescpy-at-gmail.com
python training and technical consulting
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com

From garry.bettle at gmail.com  Mon Dec 22 20:27:46 2008
From: garry.bettle at gmail.com (Garry Bettle)
Date: Mon, 22 Dec 2008 20:27:46 +0100
Subject: [Tutor] python parser
Message-ID: <f8d7009c0812221127v6b881773jf8d730f35a7771f7@mail.gmail.com>

On Mon, 22 Dec 2008 09:39:37 -0800, johnf wrote:
> Well I'm attempting to convert VFP and MsSQL (stored procedures and triggers)
> to Python and Postgres (functions and triggers).  Actually, python is very
> close to VFP and I would convert very well.  MsSQL is another question.

Hi John,

I hope this message finds you well.

You might be interested in the following:

http://dabodev.com/

"Dabo is a 3-tier, cross-platform application development framework,
written in Python atop the wxPython GUI toolkit. And while Dabo is
designed to create database-centric apps, that is not a requirement.
Lots of people are using Dabo for the GUI tools to create apps that
have no need to connect to a database at all."

NB:  The VFP-angle is well and truely catered for:

"Background

Dabo's authors, Ed Leafe and Paul McNett, have strong backgrounds in
database application development using the awesome and underrated
Microsoft Visual FoxPro development environment.

While Visual FoxPro shines at developing data-centric applications, it
has one limitation that cannot be ignored: it only runs on Microsoft
Windows, and Ed and Paul both have clients that want their
applications to run on Linux and Macintosh. We are sure we are not
alone in this regard: it is a multi-platform world with more diverse
needs than one vendor can fulfill.

Ed and Paul got to talking one day: Paul had been researching various
multiplatform GUI toolkits for about 18 months, and Ed has lots of
experience developing the Visual FoxPro Codebook framework. We decided
to work together to make a framework for developing robust
data-centric applications for multi-platform deployment. We've come up
with a design that is simple, flexible, and robust, and we've begun
developing our own client applications using the Dabo framework."

G.

From kent37 at tds.net  Mon Dec 22 20:56:16 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 22 Dec 2008 14:56:16 -0500
Subject: [Tutor] Very basic question about lists
In-Reply-To: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
Message-ID: <1c2a2c590812221156m248b2a08g1cfaf098d41c7e18@mail.gmail.com>

On Mon, Dec 22, 2008 at 1:33 PM, Eduardo Vieira <eduardo.susan at gmail.com> wrote:

> if 'arr' or 'bell' in item:

The interpreter sees this as
  if ('arr') or ('bell' in item):

'arr' always evaluates to True so the condition is always true. The
correct way to express this condition is
  if 'arr' in item or 'bell' in item:

Kent

From wescpy at gmail.com  Mon Dec 22 21:19:40 2008
From: wescpy at gmail.com (wesley chun)
Date: Mon, 22 Dec 2008 12:19:40 -0800
Subject: [Tutor] Very basic question about lists
In-Reply-To: <1c2a2c590812221156m248b2a08g1cfaf098d41c7e18@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
	<1c2a2c590812221156m248b2a08g1cfaf098d41c7e18@mail.gmail.com>
Message-ID: <78b3a9580812221219x79bfd03am526cf28172925e64@mail.gmail.com>

>> if 'arr' or 'bell' in item:
>
> The interpreter sees this as
>  if ('arr') or ('bell' in item):
>
> 'arr' always evaluates to True so the condition is always true. The
> correct way to express this condition is
>  if 'arr' in item or 'bell' in item:

arrgh. yes, i saw this too but forgot to mention it in my reply. the
reason why it is, as kent has stated is that any non-empty container,
i.e., 'arr', always evaluates to Boolean True. the only string that
has a False value is the empty string, or "".

in addition, i think (and i may be wrong about this) that he really
wanted to do:

if 'arr' in list1 or 'bell' in list1...

"in item" is a substring check and not a list membership query.

-- wesley

From denis.spir at free.fr  Mon Dec 22 21:36:40 2008
From: denis.spir at free.fr (spir)
Date: Mon, 22 Dec 2008 21:36:40 +0100
Subject: [Tutor] Very basic question about lists
In-Reply-To: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
Message-ID: <1229978200.7389.24.camel@o>

Le lundi 22 d?cembre 2008 ? 11:33 -0700, Eduardo Vieira a ?crit :
> Hello, I'm trying to teach my self programming with python and there
> are some basic things that stumps me:
> Given this code:
> ###
> list1 = ['arr', 'bre', 'grau', 'lower', 'tudo']
> for item in list1:
>     if 'arr' in item:
>         print list1
> ###
> The output is (as expected):
> ['arr', 'bre', 'grau', 'lower', 'tudo']
> 
> If I change my condition to:
> if 'arr' or 'bell' in item:
> or to this:
> if 'arr' or 'grau' in item:
> 
> I get this result:
> ['arr', 'bre', 'grau', 'lower', 'tudo']
> ['arr', 'bre', 'grau', 'lower', 'tudo']
> ['arr', 'bre', 'grau', 'lower', 'tudo']
> ['arr', 'bre', 'grau', 'lower', 'tudo']
> ['arr', 'bre', 'grau', 'lower', 'tudo']
> 
> Why this? I guess I'm not grasping the use of AND and OR

Actually, you are right, I guess. There are here two rather subtile
issues. (In addition to the questions about what you really *mean* with
this piece of code):
-1- What python understands reading "if 'arr' or 'bell' in item:"
-2- What logical value python given to several kinds of objects.

About the first point, notice that you write an 'or' in the middle of a
logical expression:

if 'arr' *or* 'bell' in item

Then, the problem for any reader, be it human or mechanical, is to guess
what you intend to relate with 'or'. On left side, no problem, there is
only 'arr'. On right hand, you probably mean to englobe only 'bell', but
how does python know that? To solve this question, any language defines
an operator precedence (priority) order -- which is nearly the same for
all computer languages and inherits from conventional logic. Below the
table for python:

===================================
Operators and their evaluation order 
        Highest
        Operator
        Comment
  
, [...] {...} `...` 
Tuple, list & dict.
creation; string conv. 
s[i] s[i:j] s.attr
f(...) 
indexing & slicing;
attributes, fct calls 
+x, -x, ~x 
Unary operators 
x**y 
Power 
x*y x/y x%y
mult, division, modulo 
x+y x-y 
addition, substraction 
x<<y   x>>y 
Bit shifting 
x&y 
Bitwise and 
x^y 
Bitwise exclusive or 
x|y 
Bitwise or 
x<y  x<=y  x>y  x>=y
x==y x!=y  x<>y
x is y   x is not y
x in s   x not in s 
Comparison, 
identity, 
membership 
not x 
boolean negation 
x and y 
boolean and 
x or y 
boolean or 
        Lowest 
lambda args: expr 
anonymous function
=================================

As you can see, 'or' is very low, which means that it will be aplied
very late in any logical expression. 'in' comes befores. As you can now
guess, this means that your expression is equal to:

if ('arr') or ('bell' in item)

Lookind at the table, you will understand that, for instance:
if a and b or c	<==> if (a and b) or c
if a or b and c <==> if a or (b and c)
Right?

Now, to the second issue -- which is /according to me/ (others will not
agree) a serious default of python: in addition to logical literals
(True and False) and results of logical operators (and, or, in,...),
python gives a boolean logical value to *all* objects. Which means that:

if ( "todu b?m!" and 3 or file("/home/spir/example.txt",'r') )

is perfectly valid in python. Actually, python considers that anything
that is not "nul" (zero, or empty) has a True logical value. So that
'arr' is True for python. Then your expression above is always True
whatever the right side of the 'or' operator. 

for item in list1:
    if 'arr' or (whatever you like):
        print list1

Your loop will test the condition 5 times, because there are 5 items in
the list. The condition will be True 5 times: the list will print 5
times.
Note that you stepped right from the start on a very tricky trap of
python: most of the language items, and examples and trials you may find
or do will work in a coherent way, meaning the way you expect -- if ever
you have a consistent view of the problem. 

Ecco!

Denis

> Thanks,
> 
> Eduardo
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
> 


From eike.welk at gmx.net  Mon Dec 22 21:54:27 2008
From: eike.welk at gmx.net (Eike Welk)
Date: Mon, 22 Dec 2008 21:54:27 +0100
Subject: [Tutor] python parser
In-Reply-To: <200812220939.37750.jfabiani@yolo.com>
References: <200812220718.41305.jfabiani@yolo.com> <494FCB21.606@gmail.com>
	<200812220939.37750.jfabiani@yolo.com>
Message-ID: <200812222154.27480.eike.welk@gmx.net>

Hi John! 

I have written a (currently mostly defunct) compiler in Python for a 
specialized programming language. The parser may serve as an example 
for you.

Introduction:
http://freeode.berlios.de/

The parser:
https://svn.berlios.de/wsvn/freeode/trunk/freeode_py/freeode/simlparser.py

The method --- Parser._defineLanguageSyntax --- creates the Pyparsing 
object. There are gigantic amounts of (mostly correct) comments in 
the file. Excuse the bad English and the typos. The style is somewhat 
adapted to the IDE Pydev. 

The parser reads the program text (no scanner) and creates a tree 
structure from it. I call it AST or Parse Tree (I can't decide how to 
call it). This tree is used in subsequent passes of the compiler.

I use a modified version of Pyparsing where I fixed things that I 
considered bugs, and where I implemented some of my wishes:
https://svn.berlios.de/wsvn/freeode/trunk/freeode_py/freeode/third_party/pyparsing.py

Kind regards,
Eike.

From eduardo.susan at gmail.com  Mon Dec 22 22:27:02 2008
From: eduardo.susan at gmail.com (Eduardo Vieira)
Date: Mon, 22 Dec 2008 14:27:02 -0700
Subject: [Tutor] Very basic question about lists
In-Reply-To: <78b3a9580812221219x79bfd03am526cf28172925e64@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
	<1c2a2c590812221156m248b2a08g1cfaf098d41c7e18@mail.gmail.com>
	<78b3a9580812221219x79bfd03am526cf28172925e64@mail.gmail.com>
Message-ID: <9356b9f30812221327t2d474866n47415604efdaa76b@mail.gmail.com>

Wesley wrote:
On Mon, Dec 22, 2008 at 1:19 PM, wesley chun <wescpy at gmail.com> wrote:

>
> in addition, i think (and i may be wrong about this) that he really
> wanted to do:
>
> if 'arr' in list1 or 'bell' in list1...
>

Thanks for all the replies. Yes that was actually what I meant. My
mistake too was that I gave you all a wrong example to explain my
problem, sorry. The following example will explain better:
list1 = ['ar', 'fir', 'wo']
list2 = ['ber', 'gar', 'gt']
list3 = ['hu', 'mo', 'ko', 'tr']
list4 = ['q', 'wer', 'duh']

whole = [list1, list2, list3, list4]
for item in whole:
    if 'ar' or 'ko' in item:
        print item

So, the unexpected result was that I got all lists printed, when I
expected only list1 and list3. Now, I don't know if I still understand
the explanation given by
spir -- I'll reread more carefully--, but I know that the code to get
what I expect is this instead:
for item in whole:
    for word in item:
        if word == 'ar' or word == 'ko':
            print item

I see I have to do a loop inside a loop and that this the right expression
if word == 'ar' or word == 'ko':

but this is not:
if word == 'ar' or 'ko':

From bgailer at gmail.com  Tue Dec 23 00:03:44 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 22 Dec 2008 18:03:44 -0500
Subject: [Tutor] python parser
In-Reply-To: <200812221042.09085.jfabiani@yolo.com>
References: <200812220718.41305.jfabiani@yolo.com> <giomjd$1t8$1@ger.gmane.org>
	<200812221042.09085.jfabiani@yolo.com>
Message-ID: <49501CD0.4010903@gmail.com>

More thoughts on converting VFP to Python:

line-by-line can take into account control structures. One just 
increases or decreases the indent when encountering the start or end of 
a structure.

a bigger challenge is handling the work-area related commands such as 
Scan, Replace, Skip, Set Relation, ....

the concept of data sessions

macro substitution

all the GUI stuff would be translated to one of the python GUI packages. 
Not a trivial task!

An outline:

create initial dictionary of all initial special characters, keywords 
including their abbreviations, ...?
create dictionary to hold all user-generated names (variables, classes, 
procedures, windows, ...?)
awareness while scanning of #define and blocks such as text .. endtext 
to ignore
scan file for procedure/function/define
 
certain initial characters take precedence = ? & # * && @ \
this list may be extended temporarily by commands like text
; is a special final character

assignment statement?
initial word a keyword or function?
if none of the above error?

and on and on.

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From wescpy at gmail.com  Tue Dec 23 00:36:11 2008
From: wescpy at gmail.com (wesley chun)
Date: Mon, 22 Dec 2008 15:36:11 -0800
Subject: [Tutor] Very basic question about lists
In-Reply-To: <9356b9f30812221327t2d474866n47415604efdaa76b@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
	<1c2a2c590812221156m248b2a08g1cfaf098d41c7e18@mail.gmail.com>
	<78b3a9580812221219x79bfd03am526cf28172925e64@mail.gmail.com>
	<9356b9f30812221327t2d474866n47415604efdaa76b@mail.gmail.com>
Message-ID: <78b3a9580812221536i64252c4csad369c992b104911@mail.gmail.com>

> list1 = ['ar', 'fir', 'wo']
> list2 = ['ber', 'gar', 'gt']
> list3 = ['hu', 'mo', 'ko', 'tr']
> list4 = ['q', 'wer', 'duh']
>
> whole = [list1, list2, list3, list4]
> for item in whole:
>    if 'ar' or 'ko' in item:
>        print item
>
> So, the unexpected result was that I got all lists printed, when I
> expected only list1 and list3. Now, I don't know if I still understand
> the explanation given by spir -- I'll reread more carefully--, but I
> know that the code to get what I expect is this instead:
> for item in whole:
>    for word in item:
>        if word == 'ar' or word == 'ko':
>            print item
>
> I see I have to do a loop inside a loop and that this the right expression
> if word == 'ar' or word == 'ko':
>
> but this is not:
> if word == 'ar' or 'ko':


correct, but i *still* don't think you need to do an inner loop... it
seems you're just trying to see whether a word is in the list, not
checking for substrings. in fact, the lists can be inside another list
too. couple this with *not* looping through each list looking for
something, we have the following:

>>> whole = [
...     ['ar', 'fir', 'wo'],
...     ['ber', 'gar', 'gt'],
...     ['hu', 'mo', 'ko', 'tr'],
...     ['q', 'wer', 'duh'],
... ]
>>>
>>> for item in whole:
...     if 'ar' in item or 'ko' in item:
...         print item
...
['ar', 'fir', 'wo']
['hu', 'mo', 'ko', 'tr']

there... those are list1 and list3 right? again, the secret is in IN. :-)

hope this helps!
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2007,2001
"Python Fundamentals", Prentice Hall, (c)2009
    http://corepython.com

wesley.j.chun :: wescpy-at-gmail.com
python training and technical consulting
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com

From steve at alchemy.com  Tue Dec 23 01:01:31 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Mon, 22 Dec 2008 16:01:31 -0800
Subject: [Tutor] Very basic question about lists
In-Reply-To: <78b3a9580812221536i64252c4csad369c992b104911@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>	<1c2a2c590812221156m248b2a08g1cfaf098d41c7e18@mail.gmail.com>	<78b3a9580812221219x79bfd03am526cf28172925e64@mail.gmail.com>	<9356b9f30812221327t2d474866n47415604efdaa76b@mail.gmail.com>
	<78b3a9580812221536i64252c4csad369c992b104911@mail.gmail.com>
Message-ID: <49502A5B.6020306@alchemy.com>


>>    if 'ar' or 'ko' in item:

This is incorrect.  What you meant to say was:

if 'ar' in item or 'ko' in item:

or something equivalent to that.

"if 'ar' or 'ko' in item" means "if ('ar') is True or ('ko' in item) is 
True".  Since 'ar' is True anyway, you'll get a match every time.

From eric at ericabrahamsen.net  Tue Dec 23 08:10:58 2008
From: eric at ericabrahamsen.net (Eric Abrahamsen)
Date: Tue, 23 Dec 2008 15:10:58 +0800
Subject: [Tutor] more encoding strangeness
Message-ID: <2DBE563D-846C-4C96-9580-6951B675B32F@ericabrahamsen.net>

Hi there,

I'm configuring a python command to be used by emacs to filter a  
buffer through python markdown, and noticed something strange. If I  
run this command in the terminal:

python -c "import sys,markdown; print  
markdown.markdown(sys.stdin.read().decode('utf-8'))" <  
markdown_source.md

The file (which is encoded as utf-8 and contains Chinese characters)  
is converted and output correctly to the terminal. But if I do this to  
write the output to a file:

python -c "import sys,markdown; print  
markdown.markdown(sys.stdin.read().decode('utf-8'))" <  
markdown_source.md > output.hml

I get a UnicodeEncodeError, 'ascii' codec can't encode character  
u'\u2014'. I'm not sure where exactly this is going wrong, as print  
and sys.stdout.write() and whatnot don't provide encoding parameters.  
What's the difference between this command writing to the terminal,  
and writing to the file?

Thanks,
Eric

From kent37 at tds.net  Tue Dec 23 12:40:45 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 23 Dec 2008 06:40:45 -0500
Subject: [Tutor] more encoding strangeness
In-Reply-To: <2DBE563D-846C-4C96-9580-6951B675B32F@ericabrahamsen.net>
References: <2DBE563D-846C-4C96-9580-6951B675B32F@ericabrahamsen.net>
Message-ID: <1c2a2c590812230340g1494ed02v406b1599ab21a9e8@mail.gmail.com>

On Tue, Dec 23, 2008 at 2:10 AM, Eric Abrahamsen
<eric at ericabrahamsen.net> wrote:
> Hi there,
>
> I'm configuring a python command to be used by emacs to filter a buffer
> through python markdown, and noticed something strange. If I run this
> command in the terminal:
>
> python -c "import sys,markdown; print
> markdown.markdown(sys.stdin.read().decode('utf-8'))" < markdown_source.md
>
> The file (which is encoded as utf-8 and contains Chinese characters) is
> converted and output correctly to the terminal. But if I do this to write
> the output to a file:
>
> python -c "import sys,markdown; print
> markdown.markdown(sys.stdin.read().decode('utf-8'))" < markdown_source.md >
> output.hml
>
> I get a UnicodeEncodeError, 'ascii' codec can't encode character u'\u2014'.
> I'm not sure where exactly this is going wrong, as print and
> sys.stdout.write() and whatnot don't provide encoding parameters. What's the
> difference between this command writing to the terminal, and writing to the
> file?

sys.stdout does have an encoding:
In [1]: import sys

In [2]: sys.stdout.encoding
Out[2]: 'UTF-8'

I think print converts to the encoding of stdout, e.g.
In [3]: print u'\u2014'
?

Probably when you pipe the output, sys.stdout.encoding is ascii so the
conversion fails.

The simple solution is to convert explicitly:
print markdown.markdown(sys.stdin.read().decode('utf-8')).encode('utf-8')

Kent

From denis.spir at free.fr  Tue Dec 23 13:16:47 2008
From: denis.spir at free.fr (spir)
Date: Tue, 23 Dec 2008 13:16:47 +0100
Subject: [Tutor] Very basic question about lists
In-Reply-To: <9356b9f30812221327t2d474866n47415604efdaa76b@mail.gmail.com>
References: <9356b9f30812221033k6536cdcetd8b195c6b4be23f3@mail.gmail.com>
	<1c2a2c590812221156m248b2a08g1cfaf098d41c7e18@mail.gmail.com>
	<78b3a9580812221219x79bfd03am526cf28172925e64@mail.gmail.com>
	<9356b9f30812221327t2d474866n47415604efdaa76b@mail.gmail.com>
Message-ID: <1230034607.5833.55.camel@o>


> I see I have to do a loop inside a loop and that this the right expression
> if word == 'ar' or word == 'ko':
> 
> but this is not:
> if word == 'ar' or 'ko':

In the last example: as the 'or' operator has the least priority, it
will be applied last. Which means that all other operations in the
expression will be done first. In this case, there is only one, namely
(word=='ar'):

if ( (word == 'ar') or ('ko') ):

So that, in order to evaluate the or operation, python needs to know
whether either (word=='ar') or ('ko') is True. If either is True, the
whole is True too: this is precisely the sense of 'or'. Right?

* on left side, (word == 'ar') is true if word equals 'ar'
* on right side, 'ko' is true if... what?

This is the second point of my explanation. Conceptually, only logical
(boolean) values, and operations on these values, could/should be
allowed in logical expressions. But python also implicitely gives a
logic value to everything:

* numbers equal to zero are False
* empty containers (list, string) are False
* anything else is considered True

if 0			--> False
if ""			--> False
if []			--> False
if 1 			--> True
if [1,2,3]		--> True
if 'abc'		--> True
if 'a' and x=1 		--> True if x==1, because 'a' is True
if 'a' or x=1		--> alwaysTtrue, because 'a' is True
if word == 'ar' or 'ko'	--> always True
if 'ar' or 'ko' in seq	--> always True, because 'ar' is True

Note:
This comes from old times of programmation when False was represented by
0 and True by 1, -1, or any non-zero value (like in python). This
allowed very practicle and "clever" programming tricks, but difficult to
understand (as you see). Because conceptually wrong, in my opinion.
Python even extended that by giving a False value not only to numbers
equal to zero, but also to empty sets. This allows to write, for
instance:

if number:		# means: if number not null
	do something

if sequence:		# means: if sequence not empty
	do something

if max_number and total<max_number or collection:
	do something
# means: if there is a "max_number" condition (for it is not null) and
the actual total is less than max_number, or if there is something in
collection... do something


Denis


From gmorris at serif.com  Tue Dec 23 12:59:36 2008
From: gmorris at serif.com (Gareth at Serif)
Date: Tue, 23 Dec 2008 03:59:36 -0800 (PST)
Subject: [Tutor] MP3Info class usage
In-Reply-To: <Pine.LNX.4.44.0812191706160.16524-100000@violet.rahul.net>
References: <20934673.post@talk.nabble.com>
	<20081210140534.GM13722@inocybe.teonanacatl.org>
	<20980334.post@talk.nabble.com>
	<20081216045037.GA12325@inocybe.teonanacatl.org>
	<21071143.post@talk.nabble.com>
	<Pine.LNX.4.44.0812191617430.16524-100000@violet.rahul.net>
	<Pine.LNX.4.44.0812191706160.16524-100000@violet.rahul.net>
Message-ID: <21143262.post@talk.nabble.com>


Your advice is spot on and I'm well on my way... your Windows installation
advice should be in the readme, if anyone's listening :-)

Thanks again,
Gareth
-- 
View this message in context: http://www.nabble.com/MP3Info-class-usage-tp20934673p21143262.html
Sent from the Python - tutor mailing list archive at Nabble.com.


From Jaggojaggo+Py at gmail.com  Tue Dec 23 15:31:54 2008
From: Jaggojaggo+Py at gmail.com (Omer)
Date: Tue, 23 Dec 2008 16:31:54 +0200
Subject: [Tutor] Fwd:  Class Extend Help
In-Reply-To: <515008f10812220958y39399988k1fd2d080cb7b327b@mail.gmail.com>
References: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
	<f0b4202b0812200849k3ac5cd97sd45775c3e93ce7db@mail.gmail.com>
	<515008f10812220958y39399988k1fd2d080cb7b327b@mail.gmail.com>
Message-ID: <515008f10812230631p348d3abdt949cdabc80c55acd@mail.gmail.com>

Hey!

Thx for the help,

@Martin,
At the moment my only need is basic retrievals of source code of basic files
from the internet, so no need for urllib2 or response objects just yet.


Now, copying and pasting line by line into the interactive mode I get this:

>>> from urllib import urlopen
>>> class fetch(urlopen):
...     def __init__(self,*args):
...         urlopen.__init__(self, *args)
...         self.content = self.read()
...

Traceback (most recent call last):
  File "<interactive input>", line 1, in <module>
TypeError: Error when calling the metaclass bases
    function() argument 1 must be code, not str

Anybody, any idea what's up with that?


On Sat, Dec 20, 2008 at 6:49 PM, Richard Lovely
<roadierich at googlemail.com>wrote:

> There are three ways as I see it: using __getattr__, using a new init,
> or using a property decorator.  The last two are probably the most
> pythonic, but I'm not familiar with decorators, so here's how I'd do
> the second of the three:
>
> try:
>     from google.appengine.api.urlfetch import fetch
> except:
>     from urllib import urlopen
>
>      class fetch(urlopen):
>         def __init__(self, *args):
>             urlopen.__init__(self, *args)
>             self.content = self.read()
>
>
> This probably doesn't behave exactly the same way as the google class,
> but it should be similar enough?
> ---
> Richard "Roadie Rich" Lovely, part of the JNP|UK Famile
> www.theJNP.com
>
>
>
> 2008/12/20 Omer <Jaggojaggo+Py at gmail.com <Jaggojaggo%2BPy at gmail.com>>:
> > Hey.
> >
> > I'm trying to do something I think is basic and am failing.
> >
> > The goal is:
> > [mimicking the google urlopen syntax]
> >
> > try:
> >     from google.appengine.api.urlfetch import fetch
> > except:
> >     from urllib import urlopen as fetch
> >
> >
> > How do I add this "fetch" the property of content?
> >
> > I basically want fetch(url.com).content to replace urlopen(url.com
> ).read()
> >
> > Mind, content is not a method.
> >
> > Thoughts?
> >
> > Thx. Omer.
> >
> >
> > _______________________________________________
> > Tutor maillist  -  Tutor at python.org
> > http://mail.python.org/mailman/listinfo/tutor
> >
> >
>
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From kent37 at tds.net  Tue Dec 23 16:23:23 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 23 Dec 2008 10:23:23 -0500
Subject: [Tutor] Fwd: Class Extend Help
In-Reply-To: <515008f10812230631p348d3abdt949cdabc80c55acd@mail.gmail.com>
References: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
	<f0b4202b0812200849k3ac5cd97sd45775c3e93ce7db@mail.gmail.com>
	<515008f10812220958y39399988k1fd2d080cb7b327b@mail.gmail.com>
	<515008f10812230631p348d3abdt949cdabc80c55acd@mail.gmail.com>
Message-ID: <1c2a2c590812230723i336e8b3fo93c782d3dc0cdb57@mail.gmail.com>

On Tue, Dec 23, 2008 at 9:31 AM, Omer <Jaggojaggo+Py at gmail.com> wrote:

>>>> from urllib import urlopen
>>>> class fetch(urlopen):
> ...     def __init__(self,*args):
> ...         urlopen.__init__(self, *args)
> ...         self.content = self.read()
> ...
>
> Traceback (most recent call last):
>   File "<interactive input>", line 1, in <module>
> TypeError: Error when calling the metaclass bases
>     function() argument 1 must be code, not str
>
> Anybody, any idea what's up with that?

That's pretty obscure, not sure why you get exactly that error!

Anyway the code should be
class fetch(object):

urlopen is a function, not a class, so it can't be a base class of
fetch. There is no need for it to be a base class, either; just use
object.

Kent

From mujilias at gmail.com  Tue Dec 23 16:30:37 2008
From: mujilias at gmail.com (moham ilias)
Date: Tue, 23 Dec 2008 21:00:37 +0530
Subject: [Tutor] help needed from python beginner
Message-ID: <74b58e470812230730n4c3c5d1eg9f44a87b1bf92d8@mail.gmail.com>

can anybody help me to get the example codes for some existing python
projects. pls help in this regard
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From roadierich at googlemail.com  Tue Dec 23 17:03:41 2008
From: roadierich at googlemail.com (Richard Lovely)
Date: Tue, 23 Dec 2008 16:03:41 +0000
Subject: [Tutor] Fwd: Class Extend Help
In-Reply-To: <1c2a2c590812230723i336e8b3fo93c782d3dc0cdb57@mail.gmail.com>
References: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
	<f0b4202b0812200849k3ac5cd97sd45775c3e93ce7db@mail.gmail.com>
	<515008f10812220958y39399988k1fd2d080cb7b327b@mail.gmail.com>
	<515008f10812230631p348d3abdt949cdabc80c55acd@mail.gmail.com>
	<1c2a2c590812230723i336e8b3fo93c782d3dc0cdb57@mail.gmail.com>
Message-ID: <f0b4202b0812230803u781d339fy14e10e5a96f27d79@mail.gmail.com>

OK, going on Kent's post:

from urllib import urlopen

class fetch(object):
    def __init__(self, *args):
        self.response = urlopen(*args)
        self.content = self.response.read()


I forgot urlopen was a function.  It made sense in my head for it to
be a class, instead of _returning_ a class.

It's trying to call __init__ on a functionType instance, and it's
getting confused.

See http://dpaste.com/hold/101951/ for another example.  The error
message is something cryptic, but between #python and I we think it's
something to do with calling type().
---
Richard "Roadie Rich" Lovely, part of the JNP|UK Famile
www.theJNP.com



2008/12/23 Kent Johnson <kent37 at tds.net>:
> On Tue, Dec 23, 2008 at 9:31 AM, Omer <Jaggojaggo+Py at gmail.com> wrote:
>
>>>>> from urllib import urlopen
>>>>> class fetch(urlopen):
>> ...     def __init__(self,*args):
>> ...         urlopen.__init__(self, *args)
>> ...         self.content = self.read()
>> ...
>>
>> Traceback (most recent call last):
>>   File "<interactive input>", line 1, in <module>
>> TypeError: Error when calling the metaclass bases
>>     function() argument 1 must be code, not str
>>
>> Anybody, any idea what's up with that?
>
> That's pretty obscure, not sure why you get exactly that error!
>
> Anyway the code should be
> class fetch(object):
>
> urlopen is a function, not a class, so it can't be a base class of
> fetch. There is no need for it to be a base class, either; just use
> object.
>
> Kent
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

From kent37 at tds.net  Tue Dec 23 19:09:53 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 23 Dec 2008 13:09:53 -0500
Subject: [Tutor] help needed from python beginner
In-Reply-To: <74b58e470812230730n4c3c5d1eg9f44a87b1bf92d8@mail.gmail.com>
References: <74b58e470812230730n4c3c5d1eg9f44a87b1bf92d8@mail.gmail.com>
Message-ID: <1c2a2c590812231009l34d238abk1109aa25dda66c68@mail.gmail.com>

On Tue, Dec 23, 2008 at 10:30 AM, moham ilias <mujilias at gmail.com> wrote:
> can anybody help me to get the example codes for some existing python
> projects. pls help in this regard

I'm not sure I understand your question. Do you want examples to look at?

Most of the Python standard library is written in Python so that is a
good source for examples. You can also look at projects in the Python
Package Index. Sourceforge and Google Code also have many Python
projects.
http://pypi.python.org/pypi
http://sourceforge.net/search/?type_of_search=soft&words=python
http://code.google.com/hosting/search?q=label%3aPython

Kent

From alan.gauld at btinternet.com  Tue Dec 23 19:58:44 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Tue, 23 Dec 2008 18:58:44 -0000
Subject: [Tutor] help needed from python beginner
References: <74b58e470812230730n4c3c5d1eg9f44a87b1bf92d8@mail.gmail.com>
Message-ID: <gircde$839$1@ger.gmane.org>


"moham ilias" <mujilias at gmail.com> wrote in message 
news:74b58e470812230730n4c3c5d1eg9f44a87b1bf92d8 at mail.gmail.com...
> can anybody help me to get the example codes for some existing 
> python
> projects. pls help in this regard
>

For simple examples try the Useless Python web site.

In particular check out the link to the old site, it has more
examples than the new site last time I looked...

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From msh at blisses.org  Tue Dec 23 21:10:29 2008
From: msh at blisses.org (Matt Herzog)
Date: Tue, 23 Dec 2008 15:10:29 -0500
Subject: [Tutor] optparse
Message-ID: <20081223201029.GA29361@chicago.blisses.org>

Hi All.

I want to write a script that will emulate grep to some extent. This is just an exercise for me. I want to run the script like this:

./pythongrep directory searchstring

Just like grep, I want it to print: filename, instance_of_match

As of now, the script can't find anything I tell it to look for. It prints, "None." Thanks for any advice.


import optparse
import os
import re

def main():

    p = optparse.OptionParser(description="Python grepper", prog="greppar", version="0.1", usage="usage: %prog directory regex")

    options, arguments = p.parse_args()
    if len(arguments) == 2:
        directory = arguments[0]
        regex = arguments[1]

        s = re.compile(regex)

        for filename in os.listdir(directory):
            result = re.match(s, filename)
    print result

    else:
        p.print_help()

if __name__ == '__main__':
    main()



-- 
I fear you speak upon the rack,
Where men enforced do speak anything.

- William Shakespeare

From bgailer at gmail.com  Tue Dec 23 21:47:31 2008
From: bgailer at gmail.com (bob gailer)
Date: Tue, 23 Dec 2008 15:47:31 -0500
Subject: [Tutor] python parser
In-Reply-To: <200812222159.49108.jfabiani@yolo.com>
References: <200812220718.41305.jfabiani@yolo.com>
	<200812221042.09085.jfabiani@yolo.com> <49501CD0.4010903@gmail.com>
	<200812222159.49108.jfabiani@yolo.com>
Message-ID: <49514E63.4010408@gmail.com>

I'm forwarding this to the list.

Please always reply-all so a copy goes to the list.

johnf wrote:
> On Monday 22 December 2008 03:03:44 pm you wrote:
>   
>> More thoughts on converting VFP to Python:
>>
>> line-by-line can take into account control structures. One just
>> increases or decreases the indent when encountering the start or end of
>> a structure.
>>
>> a bigger challenge is handling the work-area related commands such as
>> Scan, Replace, Skip, Set Relation, ....
>>     
>
> Actually Bob I'm using Dabo which has the above covered.  You should take a 
> close look at Dabo.  I am able to do most everything I've ever done in VFP.  
> I don't use IDE Dabo provides and I'm able to get everything done.  At this 
> point I can almost copy any VFP form.
>   
>> the concept of data sessions
>>     
>
> So far I'm able to read the dbc and have most of what is required for the data 
> sessions
>   
>> macro substitution
>>     
>
> That looks like a problem for the moment.
>   
>> all the GUI stuff would be translated to one of the python GUI packages.
>> Not a trivial task!
>>     
>
> So far it has not been to bad.  The real issue is converting to sizers.  But 
> the windows side complete.
>   
>> An outline:
>>
>> create initial dictionary of all initial special characters, keywords
>> including their abbreviations, ...?
>> create dictionary to hold all user-generated names (variables, classes,
>> procedures, windows, ...?)
>> awareness while scanning of #define and blocks such as text .. endtext
>> to ignore
>> scan file for procedure/function/define
>>
>> certain initial characters take precedence = ? & # * && @ \
>> this list may be extended temporarily by commands like text
>> ; is a special final character
>>
>> assignment statement?
>> initial word a keyword or function?
>> if none of the above error?
>>
>> and on and on.
>>     
>
> If I had a decent parser I think the rest would be easy.  But I don't and I do 
> not understand the all the CS stuff.  
>
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From kent37 at tds.net  Tue Dec 23 22:22:29 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 23 Dec 2008 16:22:29 -0500
Subject: [Tutor] optparse
In-Reply-To: <20081223201029.GA29361@chicago.blisses.org>
References: <20081223201029.GA29361@chicago.blisses.org>
Message-ID: <1c2a2c590812231322n75fe30b6gaf632b107079f4f1@mail.gmail.com>

On Tue, Dec 23, 2008 at 3:10 PM, Matt Herzog <msh at blisses.org> wrote:
>        for filename in os.listdir(directory):
>            result = re.match(s, filename)
>    print result

You never open and read the files. You are searching for the pattern
in the filename, not in the contents of the file.

If there is no match, result will be None. You need to test it and
print it only if it is not None. (Actually I don't think you want to
print the match object, you want to print the filename and the line of
the file that matches. But one thing at a time...) This test and print
should be inside the "for filename" loop; your print statement is
outside the loop.

Kent

From alan.gauld at btinternet.com  Wed Dec 24 02:12:55 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 24 Dec 2008 01:12:55 -0000
Subject: [Tutor] optparse
References: <20081223201029.GA29361@chicago.blisses.org>
	<1c2a2c590812231322n75fe30b6gaf632b107079f4f1@mail.gmail.com>
Message-ID: <gis2b1$3nk$1@ger.gmane.org>


"Kent Johnson" <kent37 at tds.net> wrote

>>        for filename in os.listdir(directory):
>>            result = re.match(s, filename)
>>    print result
>
> You never open and read the files. You are searching for the pattern
> in the filename, not in the contents of the file.

Also note that match() only searches starting at the start of the 
string.

Thus match will find foo at

foobar

but not in

sofoo

You usually need to use search()  to find the pattern anywhere
within the string.

Also look at the thread earlier this week on using listdir() and
the fileinput module.

HTH,


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From ajarncolin at gmail.com  Wed Dec 24 02:20:21 2008
From: ajarncolin at gmail.com (col speed)
Date: Wed, 24 Dec 2008 08:20:21 +0700
Subject: [Tutor] help finding recurring cycle
Message-ID: <6a1b26420812231720h92e2655qc8cebe1a2ecfdfff@mail.gmail.com>

Hello there, I am learning python as a hobby in my spare time. I enjoy doing
"project euler", not that I am any good at maths, but it gives me problems
to solve in python!
Please Note: I do not expect (or want) you to give me the solution, if you
could just point me in the right direction - that would be great.

The problem is as follows:

*A unit fraction contains 1 in the numerator. The decimal representation of
the unit fractions with denominators 2 to 10 are given:*

 [image: ^(]*1/2*[image: )][image: _(][image: )]*= **0.5*  [image:
^(]*1/3*[image:
)][image: _(][image: )]*= **0.(3)*  [image: ^(]*1/4*[image: )][image:
_(][image:
)]*= **0.25*  [image: ^(]*1/5*[image: )][image: _(][image: )]*= **0.2*  [image:
^(]*1/6*[image: )][image: _(][image: )]*= **0.1(6)*  [image: ^(]*1/7*[image:
)][image: _(][image: )]*= **0.(142857)*  [image: ^(]*1/8*[image: )][image:
_(][image: )]*= **0.125*  [image: ^(]*1/9*[image: )][image: _(][image: )]*=
**0.(1)*  [image: ^(]*1/10*[image: )][image: _(][image: )]*= **0.1*

*Where 0.1(6) means 0.166666..., and has a 1-digit recurring cycle. It can
be seen that 1/7 has a 6-digit recurring cycle.*[image: ^(][image: )][image:
_(][image: )]

*Find the value of **d [image: <] 1000 for which 1/d contains the longest
recurring cycle in its decimal fraction part.*


I've written a "division" function that gives more decimal places than the
one already in python. What my poor old brain can't work out is how to find
a "recurring cycle" which isn't disastrously complicated (as the cycle
doesn't always include the first decimal places and the length is unknown).

Any ideas would be greatly appreciated.

Thanks in advance

Colin
[image: ^(][image: )][image: _(][image: )]
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From kent37 at tds.net  Wed Dec 24 03:38:53 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 23 Dec 2008 21:38:53 -0500
Subject: [Tutor] help finding recurring cycle
In-Reply-To: <6a1b26420812231720h92e2655qc8cebe1a2ecfdfff@mail.gmail.com>
References: <6a1b26420812231720h92e2655qc8cebe1a2ecfdfff@mail.gmail.com>
Message-ID: <1c2a2c590812231838k58a20b3amc544db313ed4dd35@mail.gmail.com>

On Tue, Dec 23, 2008 at 8:20 PM, col speed <ajarncolin at gmail.com> wrote:

> I've written a "division" function that gives more decimal places than the
> one already in python. What my poor old brain can't work out is how to find
> a "recurring cycle" which isn't disastrously complicated (as the cycle
> doesn't always include the first decimal places and the length is unknown).

I would look for repetition in the remainder (the dividend) at each
step. Perhaps keep a dict which maps dividend to position, then when
you get a repeat you can figure out how long the cycle is.

Kent

From bgailer at gmail.com  Wed Dec 24 03:48:51 2008
From: bgailer at gmail.com (bob gailer)
Date: Tue, 23 Dec 2008 21:48:51 -0500
Subject: [Tutor] help finding recurring cycle
In-Reply-To: <1c2a2c590812231838k58a20b3amc544db313ed4dd35@mail.gmail.com>
References: <6a1b26420812231720h92e2655qc8cebe1a2ecfdfff@mail.gmail.com>
	<1c2a2c590812231838k58a20b3amc544db313ed4dd35@mail.gmail.com>
Message-ID: <4951A313.6060905@gmail.com>

Kent Johnson wrote:
> On Tue, Dec 23, 2008 at 8:20 PM, col speed <ajarncolin at gmail.com> wrote:
>
>   
>> I've written a "division" function that gives more decimal places than the
>> one already in python. What my poor old brain can't work out is how to find
>> a "recurring cycle" which isn't disastrously complicated (as the cycle
>> doesn't always include the first decimal places and the length is unknown).
>>     
>
> I would look for repetition in the remainder (the dividend) at each
> step. Perhaps keep a dict which maps dividend to position, then when
> you get a repeat you can figure out how long the cycle is.
>
> Kent
>   

Check out http://en.wikipedia.org/wiki/Repeating_decimal.

Section 5 How a repeating or terminating decimal expansion is found 
illustrates the above.

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From ballerz4ishi at sbcglobal.net  Wed Dec 24 04:17:33 2008
From: ballerz4ishi at sbcglobal.net (Ishan Puri)
Date: Tue, 23 Dec 2008 19:17:33 -0800 (PST)
Subject: [Tutor] Word Frequency Chart
Message-ID: <744263.77070.qm@web83304.mail.sp1.yahoo.com>

Hello,
    I am a beginner with Python but I understand a lot of linguistics. I am a high school student. I needed help (from the beginning) making a word frequency chart that I can use to chart out the numerical frequencies of words. Usually I can understand the code if it is annotated well, but I am not familiar with the functions and so forth. It would be awesome if someone could make a program that would chart frequencies for me. I have the corpora already. If the program could have something like "Type filename:" when I run it that would be fantastic. I have pylab as well, so the code could include something that would make the chart when I type in the filename. That would be great.
    Thank you. 
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From ajarncolin at gmail.com  Wed Dec 24 06:03:53 2008
From: ajarncolin at gmail.com (col speed)
Date: Wed, 24 Dec 2008 12:03:53 +0700
Subject: [Tutor] help finding recurring cycle
In-Reply-To: <4951A313.6060905@gmail.com>
References: <6a1b26420812231720h92e2655qc8cebe1a2ecfdfff@mail.gmail.com>
	<1c2a2c590812231838k58a20b3amc544db313ed4dd35@mail.gmail.com>
	<4951A313.6060905@gmail.com>
Message-ID: <6a1b26420812232103k745c965nc449647aa50f8ea1@mail.gmail.com>

Thank you, thank you thank you! I'm now well on my way to solving my 35th
problem!! The wiki is fantastic, I thought "of course - I should have known
that!" It's easy when you know how.
Thanks again, especially for the prompt replies

2008/12/24 bob gailer <bgailer at gmail.com>

> Kent Johnson wrote:
>
>> On Tue, Dec 23, 2008 at 8:20 PM, col speed <ajarncolin at gmail.com> wrote:
>>
>>
>>
>>> I've written a "division" function that gives more decimal places than
>>> the
>>> one already in python. What my poor old brain can't work out is how to
>>> find
>>> a "recurring cycle" which isn't disastrously complicated (as the cycle
>>> doesn't always include the first decimal places and the length is
>>> unknown).
>>>
>>>
>>
>> I would look for repetition in the remainder (the dividend) at each
>> step. Perhaps keep a dict which maps dividend to position, then when
>> you get a repeat you can figure out how long the cycle is.
>>
>> Kent
>>
>>
>
> Check out http://en.wikipedia.org/wiki/Repeating_decimal.
>
> Section 5 How a repeating or terminating decimal expansion is found
> illustrates the above.
>
> --
> Bob Gailer
> Chapel Hill NC 919-636-4239
>
>
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From alan.gauld at btinternet.com  Wed Dec 24 09:43:32 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 24 Dec 2008 08:43:32 -0000
Subject: [Tutor] Word Frequency Chart
References: <744263.77070.qm@web83304.mail.sp1.yahoo.com>
Message-ID: <gissnu$jhp$1@ger.gmane.org>

"Ishan Puri" <ballerz4ishi at sbcglobal.net> wrote

> I am a high school student. I needed help (from the beginning) 
> making
> a word frequency chart that I can use to chart out the numerical 
> frequencies
> of words.

We are happy to help but as a rile we don;t write programs for you,
we help you write your own programs. (Teach a man to fish and you
feed him forever etc)

> program could have something like "Type filename:" when I run it 
> that
> would be fantastic.

OK, You can use raw_input for that.
And to capture the counts you can use a dictionary.
You will need to:

1) Capture the filename
2) open the file
3) iterate over the file, line by line
4) iterate over each line word by word
5) if the word exists in your dictionary increment the count,
    else add it to the dictionary with a count of 1

Thats probably enough for a first stage.
If you don't know how to do any of the steps above let us know but 
they
are all covered in any of the beginners tutiorials.

> I have pylab as well, so the code could include something that would
> make the chart when I type in the filename. That would be great.

You can make charts directly from Python or you could save the data
to a file that some other charting software can read (say Excel).
But get the basic daya capture right first, worry about the 
presentation later.

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From norman at khine.net  Wed Dec 24 13:25:51 2008
From: norman at khine.net (Norman Khine)
Date: Wed, 24 Dec 2008 13:25:51 +0100
Subject: [Tutor] strip function
Message-ID: <49522A4F.8050106@khine.net>


Hello,
I have difficulties in trying to stripping the following:

 >>> item_path = '/companies/company/news'
 >>> item_strip = item_path.strip('/companies')
 >>> item_strip
'y/new'
 >>>

I would like to return:

 >>> item_strip
'/company/news'

What is the best way to do this.

Thanks


From bgailer at gmail.com  Wed Dec 24 13:58:50 2008
From: bgailer at gmail.com (bob gailer)
Date: Wed, 24 Dec 2008 07:58:50 -0500
Subject: [Tutor] strip function
In-Reply-To: <49522A4F.8050106@khine.net>
References: <49522A4F.8050106@khine.net>
Message-ID: <4952320A.1040408@gmail.com>

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From kent37 at tds.net  Wed Dec 24 14:09:12 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 24 Dec 2008 08:09:12 -0500
Subject: [Tutor] strip function
In-Reply-To: <49522A4F.8050106@khine.net>
References: <49522A4F.8050106@khine.net>
Message-ID: <1c2a2c590812240509xc509a83kf6cabb5fb2b3677a@mail.gmail.com>

On Wed, Dec 24, 2008 at 7:25 AM, Norman Khine <norman at khine.net> wrote:
>
> Hello,
> I have difficulties in trying to stripping the following:
>
>>>> item_path = '/companies/company/news'
>>>> item_strip = item_path.strip('/companies')
>>>> item_strip
> 'y/new'

strip() doesn't do what you want. It removes any of the characters in
the given string, in any order.

> I would like to return:
>
>>>> item_strip
> '/company/news'
>
> What is the best way to do this.

To remove a fixed string use slicing:
item_strip = item_path[len('/companies'):]

Kent

From juhasecke at googlemail.com  Wed Dec 24 15:46:22 2008
From: juhasecke at googlemail.com (Jan Ulrich Hasecke)
Date: Wed, 24 Dec 2008 15:46:22 +0100
Subject: [Tutor] Word Frequency Chart
In-Reply-To: <744263.77070.qm@web83304.mail.sp1.yahoo.com>
References: <744263.77070.qm@web83304.mail.sp1.yahoo.com>
Message-ID: <9E2BBE7D-0CDC-420D-ABB2-87C391E5ABA7@googlemail.com>

Look at http://www.nltk.org/

Merry Christmas to all!
juh
--  
Business: http://hasecke.com --- Private: http://hasecke.eu --- Blog:  
http://www.sudelbuch.de --- History: www.generationenprojekt.de ---  
Europe: www.wikitution.org

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From cbabcock at asciiking.com  Wed Dec 24 15:06:53 2008
From: cbabcock at asciiking.com (Chris Babcock)
Date: Wed, 24 Dec 2008 07:06:53 -0700
Subject: [Tutor] Word Frequency Chart
In-Reply-To: <744263.77070.qm@web83304.mail.sp1.yahoo.com>
References: <744263.77070.qm@web83304.mail.sp1.yahoo.com>
Message-ID: <20081224070653.57aae034@mail.asciiking.com>

On Tue, 23 Dec 2008 19:17:33 -0800 (PST)
Ishan Puri <ballerz4ishi at sbcglobal.net> wrote:

> Hello,
>     I am a beginner with Python but I understand a lot of
> linguistics. I am a high school student. I needed help (from the
> beginning) making a word frequency chart that I can use to chart out
> the numerical frequencies of words. Usually I can understand the code
> if it is annotated well, but I am not familiar with the functions and
> so forth. It would be awesome if someone could make a program that
> would chart frequencies for me. I have the corpora already. If the
> program could have something like "Type filename:" when I run it that
> would be fantastic. I have pylab as well, so the code could include
> something that would make the chart when I type in the filename. That
> would be great. Thank you. 

The Natural Language Toolkit is the place to look:

http://www.nltk.org/

This is a *deep* resource for lexical analysis. You'll probably want to
follow the examples in the book first and try them with your corpora as
you go.

Chris


From emadnawfal at gmail.com  Wed Dec 24 22:04:21 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Wed, 24 Dec 2008 16:04:21 -0500
Subject: [Tutor] beginsWith multiple prefixes
Message-ID: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>

Hi Tutors,
I want a function that acts like the startswith method, but can take
multiple prefixes. As an amateur programmer, I came up with this one, and it
works fine, but my experience tells me that my solutions are not always the
best ones around. Can you please tell me what a better option might be:



def beginsWith(word, listname):
    count = 0
    x = range(len(word))
    for i in x:
        if word[:i] in listname:
            count+=1

            break

    if count > 0:
        return True
    else:
        return False


# main
text = "ana mary fify floor school security".split()

prefixes = ["an", "ma", "fi", "sec"]

for word in text:
    if beginsWith(word, prefixes):
        print(word+" (Match)")
    else:
        print(word)

#This produces the following:
IDLE 3.0      ==== No Subprocess ====
>>>
ana (Match)
mary (Match)
fify (Match)
floor
school
security (Match)
>>>

-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
http://emnawfal.googlepages.com
--------------------------------------------------------
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From bgailer at gmail.com  Thu Dec 25 00:04:37 2008
From: bgailer at gmail.com (bob gailer)
Date: Wed, 24 Dec 2008 18:04:37 -0500
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
Message-ID: <4952C005.3010200@gmail.com>

Emad Nawfal (???? ????) wrote:
> Hi Tutors,
> I want a function that acts like the startswith method, but can take 
> multiple prefixes. As an amateur programmer, I came up with this one, 
> and it works fine, but my experience tells me that my solutions are 
> not always the best ones around. Can you please tell me what a better 
> option might be:
>
>
>
> def beginsWith(word, listname):
>     count = 0
>     x = range(len(word))
>     for i in x:
>         if word[:i] in listname:
>             count+=1
>            
>             break
>    
>     if count > 0:
>         return True
>     else:
>         return False
Above does a lot more work than necessary. Try:
 
def beginsWith(word, listname):
    for prefix in listname:
       if word.startswith(prefix):
          return True
>
>
> # main
> text = "ana mary fify floor school security".split()
>
> prefixes = ["an", "ma", "fi", "sec"]
>
> for word in text:
>     if beginsWith(word, prefixes):
>         print(word+" (Match)")
>     else:
>         print(word)
>
> #This produces the following:
> IDLE 3.0      ==== No Subprocess ====
> >>>
> ana (Match)
> mary (Match)
> fify (Match)
> floor
> school
> security (Match)
> >>>
>
> -- 
> ?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? 
> ????????.....???? ???????
> "No victim has ever been more repressed and alienated than the truth"
>
> Emad Soliman Nawfal
> Indiana University, Bloomington
> http://emnawfal.googlepages.com
> --------------------------------------------------------
> ------------------------------------------------------------------------
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From bill at celestial.net  Thu Dec 25 06:51:12 2008
From: bill at celestial.net (Bill Campbell)
Date: Wed, 24 Dec 2008 21:51:12 -0800
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <4952C005.3010200@gmail.com>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
	<4952C005.3010200@gmail.com>
Message-ID: <20081225055112.GA31743@ayn.mi.celestial.com>

On Wed, Dec 24, 2008, bob gailer wrote:
> Emad Nawfal (???? ????) wrote:
>> Hi Tutors,
>> I want a function that acts like the startswith method, but can take  
>> multiple prefixes. As an amateur programmer, I came up with this one,  
>> and it works fine, but my experience tells me that my solutions are  
>> not always the best ones around. Can you please tell me what a better  
>> option might be:
...
> Above does a lot more work than necessary. Try:
>
> def beginsWith(word, listname):
>    for prefix in listname:
>       if word.startswith(prefix):
>          return True

It might be more useful to return the prefix that matched as the
caller already knows what ``word'' is.

Bill
-- 
INTERNET:   bill at celestial.com  Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/  PO Box 820; 6641 E. Mercer Way
Voice:          (206) 236-1676  Mercer Island, WA 98040-0820
Fax:            (206) 232-9186

Basic Definitions of Science:
    If it's green or wiggles, it's biology.
    If it stinks, it's chemistry.
    If it doesn't work, it's physics.

From emadnawfal at gmail.com  Thu Dec 25 12:10:51 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Thu, 25 Dec 2008 06:10:51 -0500
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <20081225055112.GA31743@ayn.mi.celestial.com>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
	<4952C005.3010200@gmail.com>
	<20081225055112.GA31743@ayn.mi.celestial.com>
Message-ID: <652641e90812250310s472c98f3tbd9de651a9511bee@mail.gmail.com>

On 12/25/08, Bill Campbell <bill at celestial.net> wrote:
>
> On Wed, Dec 24, 2008, bob gailer wrote:
> > Emad Nawfal (???? ????) wrote:
> >> Hi Tutors,
> >> I want a function that acts like the startswith method, but can take
> >> multiple prefixes. As an amateur programmer, I came up with this one,
> >> and it works fine, but my experience tells me that my solutions are
> >> not always the best ones around. Can you please tell me what a better
> >> option might be:
>
> ...
>
> > Above does a lot more work than necessary. Try:
> >
> > def beginsWith(word, listname):
> >    for prefix in listname:
> >       if word.startswith(prefix):
> >          return True
>
>
> It might be more useful to return the prefix that matched as the
> caller already knows what ``word'' is.
>
> Bill
> --
> INTERNET:   bill at celestial.com  Bill Campbell; Celestial Software LLC
> URL: http://www.celestial.com/  PO Box 820; 6641 E. Mercer Way
> Voice:          (206) 236-1676  Mercer Island, WA 98040-0820
> Fax:            (206) 232-9186
>
> Basic Definitions of Science:
>     If it's green or wiggles, it's biology.
>     If it stinks, it's chemistry.
>     If it doesn't work, it's physics.
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

Thank you so much Bob and Bill. This is really much better than mine. Bill's
suggestion is not applicable in my current script, but I believe I will need
that soon.
Thank you both.
Thank you all tutors


-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
http://emnawfal.googlepages.com
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From alan.gauld at btinternet.com  Thu Dec 25 12:40:22 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Thu, 25 Dec 2008 11:40:22 -0000
Subject: [Tutor] beginsWith multiple prefixes
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com><4952C005.3010200@gmail.com><20081225055112.GA31743@ayn.mi.celestial.com>
	<652641e90812250310s472c98f3tbd9de651a9511bee@mail.gmail.com>
Message-ID: <givrfh$k4k$1@ger.gmane.org>

"Emad Nawfal (???? ????)" <emadnawfal at gmail.com> wrote
>> >> I want a function that acts like the startswith method, but can 
>> >> take
>> >> multiple prefixes.
>> Above does a lot more work than necessary. Try:
>>
>> def beginsWith(word, listname):
>>     for prefix in listname:
>>        if word.startswith(prefix):
>>           return True
You could also make this a method of a subclass of string if you 
prefer:

class MyString(str):
   def beginswith(self, prefixes):
        for prefix in prefixes:
             if self.startswith(prefix):
                return prefix

Now you can create instances of MyString that will have all
the regular vstring methiods plus the new beginswith():

s = MyString("Welcome to my world")
if s.beginswith(["Welcome", "Hello","Howdy"]):
    print "It's friendly"

Which looks more consistent.

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld




From kent37 at tds.net  Thu Dec 25 14:17:25 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 25 Dec 2008 08:17:25 -0500
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
Message-ID: <1c2a2c590812250517o269f2cbbwb406f154d55eec2b@mail.gmail.com>

On Wed, Dec 24, 2008 at 4:04 PM, Emad Nawfal (???? ????)
<emadnawfal at gmail.com> wrote:
> Hi Tutors,
> I want a function that acts like the startswith method, but can take
> multiple prefixes. As an amateur programmer, I came up with this one, and it
> works fine, but my experience tells me that my solutions are not always the
> best ones around. Can you please tell me what a better option might be:

Since Python 2.5, startswith() accepts a tuple as the match parameter,
so you can write
def beginsWith(word, listname):
  return word.startswith(tuple(listname))

or just us startswith() directly.

Kent

From kent37 at tds.net  Thu Dec 25 14:20:31 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 25 Dec 2008 08:20:31 -0500
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <givrfh$k4k$1@ger.gmane.org>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
	<4952C005.3010200@gmail.com>
	<20081225055112.GA31743@ayn.mi.celestial.com>
	<652641e90812250310s472c98f3tbd9de651a9511bee@mail.gmail.com>
	<givrfh$k4k$1@ger.gmane.org>
Message-ID: <1c2a2c590812250520r7fe2eb4bnf0b3dda87da92ff9@mail.gmail.com>

2008/12/25 Alan Gauld <alan.gauld at btinternet.com>:

> You could also make this a method of a subclass of string if you prefer:
>
> class MyString(str):
>  def beginswith(self, prefixes):
>       for prefix in prefixes:
>            if self.startswith(prefix):
>               return prefix
>
> Now you can create instances of MyString that will have all
> the regular vstring methiods plus the new beginswith():
>
> s = MyString("Welcome to my world")
> if s.beginswith(["Welcome", "Hello","Howdy"]):
>   print "It's friendly"
>
> Which looks more consistent.

It's an appealing idea but the extra step of wrapping strings in
MyString kind of takes the shine off of it. For example something like
this is awkward:
for d in os.listdir():
  d = MyString(d)
  if d.beginswith(...):

Some languages allow you to extend a built-in class, this technique
works better there.

Kent

From emadnawfal at gmail.com  Thu Dec 25 14:31:51 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Thu, 25 Dec 2008 08:31:51 -0500
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <1c2a2c590812250517o269f2cbbwb406f154d55eec2b@mail.gmail.com>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
	<1c2a2c590812250517o269f2cbbwb406f154d55eec2b@mail.gmail.com>
Message-ID: <652641e90812250531q104e6139lc1f6f060fa33690a@mail.gmail.com>

On 12/25/08, Kent Johnson <kent37 at tds.net> wrote:
>
> On Wed, Dec 24, 2008 at 4:04 PM, Emad Nawfal (???? ????)
> <emadnawfal at gmail.com> wrote:
> > Hi Tutors,
> > I want a function that acts like the startswith method, but can take
> > multiple prefixes. As an amateur programmer, I came up with this one, and
> it
> > works fine, but my experience tells me that my solutions are not always
> the
> > best ones around. Can you please tell me what a better option might be:
>
>
> Since Python 2.5, startswith() accepts a tuple as the match parameter,
> so you can write
> def beginsWith(word, listname):
>   return word.startswith(tuple(listname))
>
> or just us startswith() directly.
>
>
> Kent
>

Thank you Kent. I read the documentation, but did not notice it, now I can
see it clearly. This also applies to endswith
Thank you all for your helpfulness.

-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
http://emnawfal.googlepages.com
--------------------------------------------------------
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From alan.gauld at btinternet.com  Thu Dec 25 18:46:40 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Thu, 25 Dec 2008 17:46:40 -0000
Subject: [Tutor] beginsWith multiple prefixes
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com><4952C005.3010200@gmail.com><20081225055112.GA31743@ayn.mi.celestial.com><652641e90812250310s472c98f3tbd9de651a9511bee@mail.gmail.com><givrfh$k4k$1@ger.gmane.org>
	<1c2a2c590812250520r7fe2eb4bnf0b3dda87da92ff9@mail.gmail.com>
Message-ID: <gj0gu1$ec$1@ger.gmane.org>


"Kent Johnson" <kent37 at tds.net> wrote

>> You could also make this a method of a subclass of string if you 
>> prefer:
>>
>> class MyString(str):
>>  def beginswith(self, prefixes):
>>       for prefix in prefixes:
>>            if self.startswith(prefix):
>>               return prefix
>
> It's an appealing idea but the extra step of wrapping strings in
> MyString kind of takes the shine off of it. For example something 
> like
> this is awkward:
> for d in os.listdir():
>  d = MyString(d)
>  if d.beginswith(...):

I would write that as:

for d in os.listdir():
    if MyString(d).beginswith(....):

Which isn't that cumbersome. d is still available for
subsequent processing and acces to normal string
methods is still useful , as in:

for d in os.listdir():
    if MyString(d).upper().beginswith(....):

But it's a matter of taste I guess.

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


>
> Some languages allow you to extend a built-in class, this technique
> works better there.
>
> Kent
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
> 



From kent37 at tds.net  Fri Dec 26 03:25:17 2008
From: kent37 at tds.net (Kent Johnson)
Date: Thu, 25 Dec 2008 21:25:17 -0500
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <gj0gu1$ec$1@ger.gmane.org>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
	<4952C005.3010200@gmail.com>
	<20081225055112.GA31743@ayn.mi.celestial.com>
	<652641e90812250310s472c98f3tbd9de651a9511bee@mail.gmail.com>
	<givrfh$k4k$1@ger.gmane.org>
	<1c2a2c590812250520r7fe2eb4bnf0b3dda87da92ff9@mail.gmail.com>
	<gj0gu1$ec$1@ger.gmane.org>
Message-ID: <1c2a2c590812251825t619f8977g4b66443dffa63bbb@mail.gmail.com>

On Thu, Dec 25, 2008 at 12:46 PM, Alan Gauld <alan.gauld at btinternet.com> wrote:

> for d in os.listdir():
>   if MyString(d).beginswith(....):
>
> Which isn't that cumbersome. d is still available for
> subsequent processing and acces to normal string
> methods is still useful , as in:
>
> for d in os.listdir():
>   if MyString(d).upper().beginswith(....):

But that won't work, the result of calling upper() will be a normal
str, not a MyString.

Kent

From prasadaraon50 at gmail.com  Fri Dec 26 07:21:19 2008
From: prasadaraon50 at gmail.com (prasad rao)
Date: Thu, 25 Dec 2008 22:21:19 -0800
Subject: [Tutor] to sort
Message-ID: <9e3fac840812252221pe3345bam7e3e3563e050c940@mail.gmail.com>

hello       I am trying to sort a list(I know there is a builtin sort
method).

     a=[21,56,35,47,94,12]
      b=[]

   for x in a:
b.append (min(a))
a.remove (min(a))
>>> a
[56, 47, 94]
>>> b
[12, 21, 35]

It is not Compleating .Doing only 3 rounds.Why?
By the way how can I view the builtin code for sort method?

Wish you all Happy Xmass.
                thanks
 Prasad
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From metolone+gmane at gmail.com  Fri Dec 26 08:27:31 2008
From: metolone+gmane at gmail.com (Mark Tolonen)
Date: Thu, 25 Dec 2008 23:27:31 -0800
Subject: [Tutor] to sort
References: <9e3fac840812252221pe3345bam7e3e3563e050c940@mail.gmail.com>
Message-ID: <gj2113$lvr$1@ger.gmane.org>


"prasad rao" <prasadaraon50 at gmail.com> wrote in message 
news:9e3fac840812252221pe3345bam7e3e3563e050c940 at mail.gmail.com...
> hello
>        I am trying to sort a list(I know there is a builtin sort method).
>
>
>      a=[21,56,35,47,94,12]
>       b=[]
>
>
>    for x in a:
> b.append (min(a))
> a.remove (min(a))
> >>> a
> [56, 47, 94]
> >>> b
> [12, 21, 35]
>
> It is not Compleating .Doing only 3 rounds.Why?

You should not change a list while iterating over it.  Instead, iterate 
until a is empty:

>>> a=[21,56,35,47,94,12]
>>> b=[]
>>> while a:
...        b.append(min(a))
...        a.remove(min(a))
...
>>> a
[]
>>> b
[12, 21, 35, 47, 56, 94]
>>>

-Mark



From alan.gauld at btinternet.com  Fri Dec 26 12:47:41 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Fri, 26 Dec 2008 11:47:41 -0000
Subject: [Tutor] beginsWith multiple prefixes
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com><4952C005.3010200@gmail.com><20081225055112.GA31743@ayn.mi.celestial.com><652641e90812250310s472c98f3tbd9de651a9511bee@mail.gmail.com><givrfh$k4k$1@ger.gmane.org><1c2a2c590812250520r7fe2eb4bnf0b3dda87da92ff9@mail.gmail.com><gj0gu1$ec$1@ger.gmane.org>
	<1c2a2c590812251825t619f8977g4b66443dffa63bbb@mail.gmail.com>
Message-ID: <gj2g8u$m2a$1@ger.gmane.org>


"Kent Johnson" <kent37 at tds.net> wrote 

>> for d in os.listdir():
>>   if MyString(d).upper().beginswith(....):
> 
> But that won't work, the result of calling upper() will be a normal
> str, not a MyString.

Ah yes. Immutability of strings strikes again. upper() returns 
a new string, I forgot about that. pity.

You can do

if MyString(d.upper()).beginswith(...)

But that loses a lot in elegance and is hardly better than 
using a fiunction.

Alan G


From alan.gauld at btinternet.com  Fri Dec 26 12:59:55 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Fri, 26 Dec 2008 11:59:55 -0000
Subject: [Tutor] to sort
References: <9e3fac840812252221pe3345bam7e3e3563e050c940@mail.gmail.com>
Message-ID: <gj2gvs$nl7$1@ger.gmane.org>


"prasad rao" <prasadaraon50 at gmail.com> wrote 

>     a=[21,56,35,47,94,12]
>      b=[]
> 
>   for x in a:
> b.append (min(a))
> a.remove (min(a))

> It is not Compleating .Doing only 3 rounds.Why?

Think about what is happening.
for x in a

x takes the next value of x after each iteration.
Each iteration reduces the size of a so after 3 iterations 
x will be the 3rd value and there are only 3 values left. 
So x is at the end of the list and the loop stops.

So as Mark said, don't change the list while iterating over 
it - its a bit like cutting off the branch of the tree that you 
are sitting on!

But why are you trying to sort in this fashion? Its 
extremely inefficient compared to using the built in 
methods.

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


From emadnawfal at gmail.com  Fri Dec 26 14:09:34 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Fri, 26 Dec 2008 08:09:34 -0500
Subject: [Tutor] commands versus subprocess, I'm confused
Message-ID: <652641e90812260509t5f5af359sa67ec8af6c8330df@mail.gmail.com>

Hello Tutors, and Happy New Year and Holidays,
suppose I have an external program that prints "testing the subprocess
module"
I know I can run it through the commands module like this:

>>> a = commands.getoutput("python3.0 hello.py")
>>> a
'testing the subprocess module'
>>> len(a)
29
>>> b = a.split()
>>> b
['testing', 'the', 'subprocess', 'module']
>>> for word in b:
...     if word[-1] == 'e': print word
...
the
module
>>>

I cannot figure out how to do the same thing in the subprocess module. Can
somebody please explain how to get the same behaviour from, say,
subprocess.call

-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington

--------------------------------------------------------
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From emadnawfal at gmail.com  Fri Dec 26 14:14:34 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Fri, 26 Dec 2008 08:14:34 -0500
Subject: [Tutor] beginsWith multiple prefixes
In-Reply-To: <gj2g8u$m2a$1@ger.gmane.org>
References: <652641e90812241304g37c74c90k6adf0060f895ef86@mail.gmail.com>
	<4952C005.3010200@gmail.com>
	<20081225055112.GA31743@ayn.mi.celestial.com>
	<652641e90812250310s472c98f3tbd9de651a9511bee@mail.gmail.com>
	<givrfh$k4k$1@ger.gmane.org>
	<1c2a2c590812250520r7fe2eb4bnf0b3dda87da92ff9@mail.gmail.com>
	<gj0gu1$ec$1@ger.gmane.org>
	<1c2a2c590812251825t619f8977g4b66443dffa63bbb@mail.gmail.com>
	<gj2g8u$m2a$1@ger.gmane.org>
Message-ID: <652641e90812260514n19af42dud2e837697ec69bd1@mail.gmail.com>

On Fri, Dec 26, 2008 at 6:47 AM, Alan Gauld <alan.gauld at btinternet.com>wrote:

>
> "Kent Johnson" <kent37 at tds.net> wrote
>
>> for d in os.listdir():
>>>  if MyString(d).upper().beginswith(....):
>>>
>>
>> But that won't work, the result of calling upper() will be a normal
>> str, not a MyString.
>>
>
> Ah yes. Immutability of strings strikes again. upper() returns a new
> string, I forgot about that. pity.
>
> You can do
>
> if MyString(d.upper()).beginswith(...)
>
> But that loses a lot in elegance and is hardly better than using a
> fiunction.
>
> Alan G
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

Thank you Alan and everybody. I simply prefer the built-in one. I had no
idea it could take a tuple.
What is amazing is that I learn  more from this list than I do from any
other source.

-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
http://emnawfal.googlepages.com
--------------------------------------------------------
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From kent37 at tds.net  Fri Dec 26 14:32:40 2008
From: kent37 at tds.net (Kent Johnson)
Date: Fri, 26 Dec 2008 08:32:40 -0500
Subject: [Tutor] to sort
In-Reply-To: <9e3fac840812252221pe3345bam7e3e3563e050c940@mail.gmail.com>
References: <9e3fac840812252221pe3345bam7e3e3563e050c940@mail.gmail.com>
Message-ID: <1c2a2c590812260532g184bb24j176a0b5d42382649@mail.gmail.com>

On Fri, Dec 26, 2008 at 1:21 AM, prasad rao <prasadaraon50 at gmail.com> wrote:

> By the way how can I view the builtin code for sort method?

Look at the source - Objects/listobject.c - starting at the comment
"Lots of code for an adaptive, stable, natural mergesort."
http://svn.python.org/view/python/trunk/Objects/listobject.c?rev=67498&view=markup

The source also includes an interesting and detailed description of
the sort algorithm:
http://svn.python.org/view/python/trunk/Objects/listsort.txt?rev=51013&view=auto

Kent

From kent37 at tds.net  Fri Dec 26 14:39:39 2008
From: kent37 at tds.net (Kent Johnson)
Date: Fri, 26 Dec 2008 08:39:39 -0500
Subject: [Tutor] commands versus subprocess, I'm confused
In-Reply-To: <652641e90812260509t5f5af359sa67ec8af6c8330df@mail.gmail.com>
References: <652641e90812260509t5f5af359sa67ec8af6c8330df@mail.gmail.com>
Message-ID: <1c2a2c590812260539y17e0d815g969ecdbf0ad1fa64@mail.gmail.com>

On Fri, Dec 26, 2008 at 8:09 AM, Emad Nawfal (???? ????)
<emadnawfal at gmail.com> wrote:
> suppose I have an external program that prints "testing the subprocess
> module"
> I know I can run it through the commands module like this:
>
>>>> a = commands.getoutput("python3.0 hello.py")
>>>> a
> 'testing the subprocess module'


> I cannot figure out how to do the same thing in the subprocess module. Can
> somebody please explain how to get the same behaviour from, say,
> subprocess.call

Sometthing like this, I think:

proc = subprocess.Popen('python3.0 hello.py',
                       shell=True,
                       stdout=subprocess.PIPE,
                       )
stdout_value = proc.communicate()[0]

(Courtesy of http://blog.doughellmann.com/2007/07/pymotw-subprocess.html)

Kent

From emadnawfal at gmail.com  Fri Dec 26 14:57:43 2008
From: emadnawfal at gmail.com (=?WINDOWS-1256?Q?Emad_Nawfal_(=DA=E3=C7=CF_=E4=E6=DD=E1)?=)
Date: Fri, 26 Dec 2008 08:57:43 -0500
Subject: [Tutor] commands versus subprocess, I'm confused
In-Reply-To: <1c2a2c590812260539y17e0d815g969ecdbf0ad1fa64@mail.gmail.com>
References: <652641e90812260509t5f5af359sa67ec8af6c8330df@mail.gmail.com>
	<1c2a2c590812260539y17e0d815g969ecdbf0ad1fa64@mail.gmail.com>
Message-ID: <652641e90812260557l5114507apbc89115bf0bda3d2@mail.gmail.com>

2008/12/26 Kent Johnson <kent37 at tds.net>

> On Fri, Dec 26, 2008 at 8:09 AM, Emad Nawfal (???? ????)
> <emadnawfal at gmail.com> wrote:
> > suppose I have an external program that prints "testing the subprocess
> > module"
> > I know I can run it through the commands module like this:
> >
> >>>> a = commands.getoutput("python3.0 hello.py")
> >>>> a
> > 'testing the subprocess module'
>
>
> > I cannot figure out how to do the same thing in the subprocess module.
> Can
> > somebody please explain how to get the same behaviour from, say,
> > subprocess.call
>
> Sometthing like this, I think:
>
> proc = subprocess.Popen('python3.0 hello.py',
>                       shell=True,
>                       stdout=subprocess.PIPE,
>                       )
> stdout_value = proc.communicate()[0]
>
> (Courtesy of http://blog.doughellmann.com/2007/07/pymotw-subprocess.html)
>
> Kent
>
Thank you Kent.
It works, but isn't the commands module much simpler?  I don't know why it's
no more available in Python3.0


-- 
?? ???? ?????? ????? ????? ??? ???? ??? ????? ?? ?????? ????????.....????
???????
"No victim has ever been more repressed and alienated than the truth"

Emad Soliman Nawfal
Indiana University, Bloomington
http://emnawfal.googlepages.com
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From alan.gauld at btinternet.com  Fri Dec 26 15:06:14 2008
From: alan.gauld at btinternet.com (ALAN GAULD)
Date: Fri, 26 Dec 2008 14:06:14 +0000 (GMT)
Subject: [Tutor] beginsWith multiple prefixes
Message-ID: <434437.35455.qm@web86705.mail.ird.yahoo.com>



> ....I simply prefer the built-in one. I had no idea it could take a tuple.

Me neither, that was a surprise goody in 2.5 that I hadn't seen before.

> What is amazing is that I learn  more from this list than I do from any other source.

Me too, and I've been subscribed for over 10 years now! :-)

Alan G.
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From alan.gauld at btinternet.com  Fri Dec 26 15:28:57 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Fri, 26 Dec 2008 14:28:57 -0000
Subject: [Tutor] commands versus subprocess, I'm confused
References: <652641e90812260509t5f5af359sa67ec8af6c8330df@mail.gmail.com><1c2a2c590812260539y17e0d815g969ecdbf0ad1fa64@mail.gmail.com>
	<652641e90812260557l5114507apbc89115bf0bda3d2@mail.gmail.com>
Message-ID: <gj2pn9$dan$1@ger.gmane.org>

"Emad Nawfal (???? ????)" <emadnawfal at gmail.com> wrote

>> proc = subprocess.Popen('python3.0 hello.py',
>>                       shell=True,
>>                       stdout=subprocess.PIPE,
>>                       )
>> stdout_value = proc.communicate()[0]

> Thank you Kent.
> It works, but isn't the commands module much simpler?  I don't know 
> why it's
> no more available in Python3.0

commands was one of many different ways to access command ouitput.
Subprocess was designed to replace all of them and provide a single
consistent mechanism.

So, yes we lost some simplicity but gained consistency.
You no longer need to figure out whether its best to use
os,system, os.popen(and which version of popen), os.spawn, commands 
etc

You just use subprocess...
HTH,
Alan G 



From reed at reedobrien.com  Fri Dec 26 16:02:56 2008
From: reed at reedobrien.com (Reed O'Brien)
Date: Fri, 26 Dec 2008 10:02:56 -0500
Subject: [Tutor] commands versus subprocess, I'm confused
In-Reply-To: <652641e90812260557l5114507apbc89115bf0bda3d2@mail.gmail.com>
References: <652641e90812260509t5f5af359sa67ec8af6c8330df@mail.gmail.com>
	<1c2a2c590812260539y17e0d815g969ecdbf0ad1fa64@mail.gmail.com>
	<652641e90812260557l5114507apbc89115bf0bda3d2@mail.gmail.com>
Message-ID: <92013FCA-91D2-414F-87DA-887FEF646522@reedobrien.com>

On Dec 26, 2008, at 8:57, "Emad Nawfal (???? ????)" <emadnawfal at g 
mail.com> wrote:

>
>
> 2008/12/26 Kent Johnson <kent37 at tds.net>
> On Fri, Dec 26, 2008 at 8:09 AM, Emad Nawfal (???? ????)
> <emadnawfal at gmail.com> wrote:
> > suppose I have an external program that prints "testing the  
> subprocess
> > module"
> > I know I can run it through the commands module like this:
> >
> >>>> a = commands.getoutput("python3.0 hello.py")
> >>>> a
> > 'testing the subprocess module'
>
>
> > I cannot figure out how to do the same thing in the subprocess  
> module. Can
> > somebody please explain how to get the same behaviour from, say,
> > subprocess.call
>
> Sometthing like this, I think:
>
> proc = subprocess.Popen('python3.0 hello.py',
>                       shell=True,
>                       stdout=subprocess.PIPE,
>                       )
> stdout_value = proc.communicate()[0]
>
> (Courtesy of http://blog.doughellmann.com/2007/07/pymotw-subprocess.html 
> )
>
> Kent
> Thank you Kent.
> It works, but isn't the commands module much simpler?  I don't know  
> why it's no more available in Python3.0

Subprocess was designed to replace all the os.popen classes since 2.4.

Commands is a wrapper for os.popen.

Aside from that commands AFAIK is unix only. Therefore it is less  
portable.

~ro 
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From prasadaraon50 at gmail.com  Sat Dec 27 07:02:10 2008
From: prasadaraon50 at gmail.com (prasad rao)
Date: Fri, 26 Dec 2008 22:02:10 -0800
Subject: [Tutor] Repply
Message-ID: <9e3fac840812262202s5a9c5059i88f0ad2cf056baa7@mail.gmail.com>

Thanks for help.

>
http://svn.python.org/view/python/trunk/Objects/listobject.c?rev=67498&view=markup

 Kent ! This is grek and latin to me.From the presence of header files it
looks C++.But headerfiles are not between '<'  and  '>' .

>But why are you trying to sort in this fashion?

Alan Gauld! Basic exercises in C++ are to find min , malimum and sorting.So
I
am just trying it in python.

Thank you Mark.

Prasad
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From alan.gauld at btinternet.com  Sat Dec 27 10:42:42 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Sat, 27 Dec 2008 09:42:42 -0000
Subject: [Tutor] Repply
References: <9e3fac840812262202s5a9c5059i88f0ad2cf056baa7@mail.gmail.com>
Message-ID: <gj4tak$s66$1@ger.gmane.org>


"prasad rao" <prasadaraon50 at gmail.com> wrote

> http://svn.python.org/view/python/trunk/Objects/listobject.c?rev=67498&view=markup
>
> Kent ! This is grek and latin to me.From the presence of header 
> files it
> looks C++.But headerfiles are not between '<'  and  '>' .

Its C rather than C++.
The <> in include statements are a variation on the "" which can also 
be used.
The differences are subtle and have to do with the search path I 
think. But its
been so long since I did serious C/++ I can't recall exactly!

> Alan Gauld! Basic exercises in C++ are to find min , malimum and 
> sorting.So
> I
> am just trying it in python.

Thats OK, I just wondered if you had some special algorithm you
needed to use or something.

Alan G. 



From srilyk at gmail.com  Sat Dec 27 18:36:34 2008
From: srilyk at gmail.com (W W)
Date: Sat, 27 Dec 2008 11:36:34 -0600
Subject: [Tutor] Repply
In-Reply-To: <gj4tak$s66$1@ger.gmane.org>
References: <9e3fac840812262202s5a9c5059i88f0ad2cf056baa7@mail.gmail.com>
	<gj4tak$s66$1@ger.gmane.org>
Message-ID: <333efb450812270936w520727b3n7e1753f1bc077d98@mail.gmail.com>

On Sat, Dec 27, 2008 at 3:42 AM, Alan Gauld <alan.gauld at btinternet.com>wrote:

>
> Its C rather than C++.
> The <> in include statements are a variation on the "" which can also be
> used.
> The differences are subtle and have to do with the search path I think. But
> its
> been so long since I did serious C/++ I can't recall exactly!


It's only been about 2 weeks since I've been in class so that's a topic on
which I can expound. "" searches the current directory before searching in
the default library. It's pretty similar to the python "import" behavior,
AFAICT.

"And now you know"
-Wayne
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From msh at blisses.org  Sat Dec 27 20:55:02 2008
From: msh at blisses.org (Matt Herzog)
Date: Sat, 27 Dec 2008 14:55:02 -0500
Subject: [Tutor] Redux: optparse
In-Reply-To: <gis2b1$3nk$1@ger.gmane.org>
References: <20081223201029.GA29361@chicago.blisses.org>
	<1c2a2c590812231322n75fe30b6gaf632b107079f4f1@mail.gmail.com>
	<gis2b1$3nk$1@ger.gmane.org>
Message-ID: <20081227195502.GC15963@chicago.blisses.org>

On Wed, Dec 24, 2008 at 01:12:55AM -0000, Alan Gauld wrote:
> 
> "Kent Johnson" <kent37 at tds.net> wrote
> 
> >>       for filename in os.listdir(directory):
> >>           result = re.match(s, filename)
> >>   print result
> >
> >You never open and read the files. You are searching for the pattern
> >in the filename, not in the contents of the file.
> 
> Also note that match() only searches starting at the start of the 
> string.
> 
> Thus match will find foo at
> 
> foobar
> 
> but not in
> 
> sofoo
> 
> You usually need to use search()  to find the pattern anywhere
> within the string.
> 
> Also look at the thread earlier this week on using listdir() and
> the fileinput module.

Hello again and thanks for the encouragement. 

I have been working on this problem again today and switched to the fileinput method. What I can't figure out now is how to pass a compiled regex to an optparse option. I'm confused ias to "option" versus "arg" when using the optparse module. In fact there seems to be no way to define what the arg should be; only options. Is the arg always implied? I have read several pages on optparse and am none the wiser.

How do I fix the rx = re.compile('-x') line below so that the string I pass on the command line gets passed into the re.compile?

#!/usr/bin/python
import fileinput, sys, string, optparse, re

#def main():
optparser = optparse.OptionParser()
optparser.add_option("-x", "--regx", help="regular expression")
# take the first argument out of sys.argv and assign it to searchterm
#searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:]
(options, args) = optparser.parse_args()

rx = re.compile('-x')

for line in fileinput.input():
    num_matches = string.count(line, rx)
if num_matches:
    print "found '%s' %d times in %s on line %d." % (rx, num_matches,
        fileinput.filename(), fileinput.filelineno())

#if __name__ == '__main__':
    #main()

> HTH,
> 
> 
> -- 
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld 
> 
> 
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor

-- 
I fear you speak upon the rack,
Where men enforced do speak anything.

- William Shakespeare

From denis.spir at free.fr  Sat Dec 27 21:48:13 2008
From: denis.spir at free.fr (spir)
Date: Sat, 27 Dec 2008 21:48:13 +0100
Subject: [Tutor] Redux: optparse
In-Reply-To: <20081227195502.GC15963@chicago.blisses.org>
References: <20081223201029.GA29361@chicago.blisses.org>
	<1c2a2c590812231322n75fe30b6gaf632b107079f4f1@mail.gmail.com>
	<gis2b1$3nk$1@ger.gmane.org>
	<20081227195502.GC15963@chicago.blisses.org>
Message-ID: <1230410893.6321.17.camel@o>

Le samedi 27 d?cembre 2008 ? 14:55 -0500, Matt Herzog a ?crit :
> On Wed, Dec 24, 2008 at 01:12:55AM -0000, Alan Gauld wrote:
> > 
> > "Kent Johnson" <kent37 at tds.net> wrote
> > 
> > >>       for filename in os.listdir(directory):
> > >>           result = re.match(s, filename)
> > >>   print result
> > >
> > >You never open and read the files. You are searching for the pattern
> > >in the filename, not in the contents of the file.
> > 
> > Also note that match() only searches starting at the start of the 
> > string.
> > 
> > Thus match will find foo at
> > 
> > foobar
> > 
> > but not in
> > 
> > sofoo
> > 
> > You usually need to use search()  to find the pattern anywhere
> > within the string.
> > 
> > Also look at the thread earlier this week on using listdir() and
> > the fileinput module.
> 
> Hello again and thanks for the encouragement. 
> 
> I have been working on this problem again today and switched to the fileinput method. What I can't figure out now is how to pass a compiled regex to an optparse option. I'm confused ias to "option" versus "arg" when using the optparse module. In fact there seems to be no way to define what the arg should be; only options. Is the arg always implied? I have read several pages on optparse and am none the wiser.
> 
> How do I fix the rx = re.compile('-x') line below so that the string I pass on the command line gets passed into the re.compile?
> 
> #!/usr/bin/python
> import fileinput, sys, string, optparse, re
> 
> #def main():
> optparser = optparse.OptionParser()
> optparser.add_option("-x", "--regx", help="regular expression")
> # take the first argument out of sys.argv and assign it to searchterm
> #searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:]
> (options, args) = optparser.parse_args()

Do you want to use optparse, or get the command line arguments yourself?
It seems the pattern string will be the first arg, will it?

> rx = re.compile('-x')

Then, if the note above is right, you have:

pat_string = sys.argv[1]
rx = re.compile(pat_string)   # pattern object

Is that what you wish to do?

> for line in fileinput.input():
>     num_matches = string.count(line, rx)

Above you are counting the number of *regex pattern* may be inside a
string. Not the number of (sub)strings matching the pattern, which is
probably what you intend.[ Also, you are using a deprecated function
"count" of the string module. Use line.count(substring) instead. Anyway,
this is probably not what you want.]
To count the number of pattern matches, you must use the
"matching" (lol) regex method, namely findall:

result_list = rx.findall(line)

> if num_matches:
>     print "found '%s' %d times in %s on line %d." % (rx, num_matches,
>         fileinput.filename(), fileinput.filelineno())

Do you want to print only the last match? If not, you need to record
matches found by the search loop into a list.

> #if __name__ == '__main__':
>     #main()



From msh at blisses.org  Sat Dec 27 22:46:59 2008
From: msh at blisses.org (Matt Herzog)
Date: Sat, 27 Dec 2008 16:46:59 -0500
Subject: [Tutor] Redux: optparse
In-Reply-To: <1230410893.6321.17.camel@o>
References: <20081223201029.GA29361@chicago.blisses.org>
	<1c2a2c590812231322n75fe30b6gaf632b107079f4f1@mail.gmail.com>
	<gis2b1$3nk$1@ger.gmane.org>
	<20081227195502.GC15963@chicago.blisses.org>
	<1230410893.6321.17.camel@o>
Message-ID: <20081227214659.GF15963@chicago.blisses.org>

> Do you want to use optparse, or get the command line arguments yourself?
> It seems the pattern string will be the first arg, will it?

Again I am confused. I assumed that optparse was the best way to pass in arguments (such as filenames) from the command line. Like so:

	./script.py -x regex *.html

> > rx = re.compile('-x')
> 
> Then, if the note above is right, you have:
> 
> pat_string = sys.argv[1]
> rx = re.compile(pat_string)   # pattern object
> 
> Is that what you wish to do?

Probablement. :) The below code does what I want:

-------------------------------------------------------------------------------
#!/usr/bin/python
import fileinput, sys, string
# Take the first argument out of sys.argv and assign it to searchterm.
searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:]
for line in fileinput.input():
   num_matches = line.count(searchterm)
   if num_matches: # A nonzero count means there was a match.
       print "found '%s' %d times in %s on line %d." % (searchterm, num_matches, fileinput.filename(), fileinput.filelineno())
-------------------------------------------------------------------------------

I wanted to use optparse instead of sys.argv. Perhaps I should study fileinput instead. I don't understand that either.
 
> > for line in fileinput.input():
> >     num_matches = string.count(line, rx)
 
> Above you are counting the number of *regex pattern* may be inside a
> string. Not the number of (sub)strings matching the pattern, which is
> probably what you intend.[ Also, you are using a deprecated function
> "count" of the string module. Use line.count(substring) instead. Anyway,
> this is probably not what you want.]
> To count the number of pattern matches, you must use the
> "matching" (lol) regex method, namely findall:
> 
> result_list = rx.findall(line)
> 
> > if num_matches:
> >     print "found '%s' %d times in %s on line %d." % (rx, num_matches,
> >         fileinput.filename(), fileinput.filelineno())
> 
> Do you want to print only the last match? If not, you need to record
> matches found by the search loop into a list.
> 
> > #if __name__ == '__main__':
> >     #main()
> 
> 
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor

-- 
I fear you speak upon the rack,
Where men enforced do speak anything.

- William Shakespeare

From btkuhn at email.unc.edu  Sun Dec 28 01:32:29 2008
From: btkuhn at email.unc.edu (btkuhn at email.unc.edu)
Date: Sat, 27 Dec 2008 19:32:29 -0500
Subject: [Tutor] Anagram creator
Message-ID: <20081227193229.msc933mmkook48wg@webmail4.isis.unc.edu>

Hi everyone,

I'm having trouble with an anagram generating program that I am writing 
in Python. My output is not what it should be and I think the reason 
has something to do with my helper functions creating a reference to a 
dictionary each time it is called rather than a new "clone" dictionary. 
Here is my main function, with explanation afterward:


    def anagramsHelper(phrase,dictionary,anagramsofar):        if 
isSolved(phrase): #returns true if the dictonary for the phrase is empty
            print anagramsofar
                      return True
        for word in dictionary:
            if wordCanBeMade(word, phrase):
                anagramsofar=anagramsofar+" "+word
                phraseclone=removeLetters(word, phrase)
                anagramsHelper(phraseclone,dictionary,anagramsofar)



Initially it takes a dictionary representing a word or phrase (eg 
{'a':2,'d':1, 'e':2}), a dictionary in the form of a list of words, and 
anagramsofar which is initially passed as "".
Next, isSolved returns true if the dictionary is empty, meaning that 
all letters in the phrase have been used up. Otherwise, for each word 
in the dictionary, the program tests whether the word can be made from 
letters in the phrase. If it can, the word is appended to phrasesofar. 
removeLetters then removes the letters that were used to make the word. 
I saved the new phrase as phraseclone as an attempt to troubleshoot; 
originally I just used the original phrase variable. Next, the function 
is recursively called with the letters removed from the phrase. The end 
result is that when the phrase dictionary is empty, "anagramsofar" is 
printed. This should generate all anagrams of a given phrase using a 
given dictionary of words.

So, for instance, I might call (from my main function):

dictionary=importDictionary()  #A list of 10,000 strings, representing 
words in the dictionary

anagramsHelper("george bush",dictionary,"")



wordCanBeMade returns a boolean "T" or "F", and I've posted the code 
for removeLetters below.

My code is not working as expected, and after a good deal of debugging 
it seems that during the recursive calls, when I remove letters from 
the dictionary they "stay removed", even though I'm trying to create a 
new dictionary with each call (so that removed letters are not 
remembered). As a result, anagramsofar gets longer with every call and 
isSolved returns True every time, since all keys are removed after the 
first few calls. Here is the function for removeLetters:


    def removeLetters(word, phrase):
        phraseclone=phrase.copy()
        for letter in word:
            phraseclone[letter]=phraseclone[letter]-1
              return phraseclone



I'm trying to create a copy of phrase with each function call and then 
return the copy to prevent the program remembering the removed 
keys...but it's not working. Does anyone see what I'm doing wrong? I 
can post the entire program if needed; I just wanted to keep things 
somewhat concise.

Thanks.

From denis.spir at free.fr  Sun Dec 28 12:03:19 2008
From: denis.spir at free.fr (spir)
Date: Sun, 28 Dec 2008 12:03:19 +0100
Subject: [Tutor] Anagram creator
In-Reply-To: <20081227193229.msc933mmkook48wg@webmail4.isis.unc.edu>
References: <20081227193229.msc933mmkook48wg@webmail4.isis.unc.edu>
Message-ID: <1230462199.6102.88.camel@o>

Le samedi 27 d?cembre 2008 ? 19:32 -0500, btkuhn at email.unc.edu a
?crit : 
> Hi everyone,
> 
> I'm having trouble with an anagram generating program that I am writing 
> in Python. My output is not what it should be and I think the reason 
> has something to do with my helper functions creating a reference to a 
> dictionary each time it is called rather than a new "clone" dictionary. 
> Here is my main function, with explanation afterward:
> 
> 
>     def anagramsHelper(phrase,dictionary,anagramsofar):        if 
> isSolved(phrase): #returns true if the dictonary for the phrase is empty
>             print anagramsofar
>                       return True
>         for word in dictionary:
>             if wordCanBeMade(word, phrase):
>                 anagramsofar=anagramsofar+" "+word
>                 phraseclone=removeLetters(word, phrase)
>                 anagramsHelper(phraseclone,dictionary,anagramsofar)
> 

There is a layout issue with this func. I guess the proper code is probably as below
(I renamed the func for the code to fit in usual width) :

def anagrHelp(phrase,dictionary,anagramsofar):
	if isSolved(phrase): #returns true if the dict is empty
		print anagramsofar
		return True
	for word in dictionary:
		if wordCanBeMade(word, phrase):
			anagramsofar=anagramsofar+" "+word
			phraseclone=removeLetters(word, phrase)
			anagrHelp(phraseclone,dictionary,anagramsofar)



> Initially it takes a dictionary representing a word or phrase (eg 
> {'a':2,'d':1, 'e':2}), a dictionary in the form of a list of words, and 
> anagramsofar which is initially passed as "".
> Next, isSolved returns true if the dictionary is empty, meaning that 
> all letters in the phrase have been used up. Otherwise, for each word 
> in the dictionary, the program tests whether the word can be made from 
> letters in the phrase. If it can, the word is appended to phrasesofar. 
> removeLetters then removes the letters that were used to make the word. 
> I saved the new phrase as phraseclone as an attempt to troubleshoot; 
> originally I just used the original phrase variable. Next, the function 
> is recursively called with the letters removed from the phrase. The end 
> result is that when the phrase dictionary is empty, "anagramsofar" is 
> printed. This should generate all anagrams of a given phrase using a 
> given dictionary of words.

I think the issue lays in the combination of loop and recursive call
(which is often a very subtile feature).

You current status is both held by angramsofar (constructed new phrase)
and phrase (unused char list). So that if you want to find it back when
backtracking to a previous stage, you need to find them both at their
value for this stage. Which means that both must be copied to be passed
as arguments for a recursive call. As of now, only phrase is cloned. So
that anagramsofar can only grow...

Denis



From kent37 at tds.net  Sun Dec 28 16:06:12 2008
From: kent37 at tds.net (Kent Johnson)
Date: Sun, 28 Dec 2008 10:06:12 -0500
Subject: [Tutor] Redux: optparse
In-Reply-To: <20081227195502.GC15963@chicago.blisses.org>
References: <20081223201029.GA29361@chicago.blisses.org>
	<1c2a2c590812231322n75fe30b6gaf632b107079f4f1@mail.gmail.com>
	<gis2b1$3nk$1@ger.gmane.org>
	<20081227195502.GC15963@chicago.blisses.org>
Message-ID: <1c2a2c590812280706m2af34c9eqfb7cc94408f836a0@mail.gmail.com>

On Sat, Dec 27, 2008 at 2:55 PM, Matt Herzog <msh at blisses.org> wrote:
> What I can't figure out now is how to pass a compiled regex to an optparse option. I'm confused ias to "option" versus "arg" when using the optparse module. In fact there seems to be no way to define what the arg should be; only options. Is the arg always implied? I have read several pages on optparse and am none the wiser.

You want to *retrieve* the regex from the option, not pass it to the
option. See below.

"args" is the positional arguments - any parameters that aren't
prefixed with a switch like "-x". They don't need any configuration.

> How do I fix the rx = re.compile('-x') line below so that the string I pass on the command line gets passed into the re.compile?
>
> #!/usr/bin/python
> import fileinput, sys, string, optparse, re
>
> #def main():
> optparser = optparse.OptionParser()
> optparser.add_option("-x", "--regx", help="regular expression")
> # take the first argument out of sys.argv and assign it to searchterm
> #searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:]
> (options, args) = optparser.parse_args()
>
> rx = re.compile('-x')

Try
  rx = re.compile(options.regx)

Kent

From sander.sweers at gmail.com  Sun Dec 28 19:09:51 2008
From: sander.sweers at gmail.com (Sander Sweers)
Date: Sun, 28 Dec 2008 19:09:51 +0100
Subject: [Tutor] telnetlib unable to cath gaierror
Message-ID: <b65fbb130812281009s38058791tb5ec6596ff2653dc@mail.gmail.com>

Hello All,

I am having issues cathing exceptions from telnetlib. What I am doing is:

-----------------------------
tc = telnetlib.Telnet()

try:
    tc.open('abc')
except gaierror:
    print 'Invalid hostname'
-----------------------------

Which gives me "NameError: name 'gaierror' is not defined" :-(

>From the interactive promt I see:

>>> tc = telnetlib.Telnet('abc')

Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    tc = telnetlib.Telnet('blah')
  File "C:\Python25\lib\telnetlib.py", line 208, in __init__
    self.open(host, port)
  File "C:\Python25\lib\telnetlib.py", line 225, in open
    for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
gaierror: (11001, 'getaddrinfo failed')

So why can I not catch it with try/except?

Thanks
Sander

From steve at alchemy.com  Sun Dec 28 19:17:30 2008
From: steve at alchemy.com (Steve Willoughby)
Date: Sun, 28 Dec 2008 10:17:30 -0800
Subject: [Tutor] telnetlib unable to cath gaierror
In-Reply-To: <b65fbb130812281009s38058791tb5ec6596ff2653dc@mail.gmail.com>
References: <b65fbb130812281009s38058791tb5ec6596ff2653dc@mail.gmail.com>
Message-ID: <20081228181730.GA74533@dragon.alchemy.com>

On Sun, Dec 28, 2008 at 07:09:51PM +0100, Sander Sweers wrote:
> I am having issues cathing exceptions from telnetlib. What I am doing is:
> except gaierror:
> Which gives me "NameError: name 'gaierror' is not defined" :-(

This error message contains your clue.  If the name you're referencing is not defined, you usually forgot to either explicitly import it, or to name it with its namespace attached.

So you either want to say:

	from telnetlib import gaierror

at the top of your script, or if you earlier said simply "import telnetlib",

then your try/except clause would be like:

	except telnetlib.gaierror:


-- 
Steve Willoughby    |  Using billion-dollar satellites
steve at alchemy.com   |  to hunt for Tupperware.

From sander.sweers at gmail.com  Sun Dec 28 20:07:41 2008
From: sander.sweers at gmail.com (Sander Sweers)
Date: Sun, 28 Dec 2008 20:07:41 +0100
Subject: [Tutor] telnetlib unable to cath gaierror
In-Reply-To: <20081228181730.GA74533@dragon.alchemy.com>
References: <b65fbb130812281009s38058791tb5ec6596ff2653dc@mail.gmail.com>
	<20081228181730.GA74533@dragon.alchemy.com>
Message-ID: <b65fbb130812281107s14a63b1bn354feb20aafcbb79@mail.gmail.com>

On Sun, Dec 28, 2008 at 19:17, Steve Willoughby <steve at alchemy.com> wrote:
> On Sun, Dec 28, 2008 at 07:09:51PM +0100, Sander Sweers wrote:
>> I am having issues cathing exceptions from telnetlib. What I am doing is:
>> except gaierror:
>> Which gives me "NameError: name 'gaierror' is not defined" :-(
>
> This error message contains your clue.  If the name you're referencing is not defined, you usually forgot to either explicitly import it, or to name it with its namespace attached.

Looking more closely it is not an error from telnetlib. It is an error
from the socket module.

>        from telnetlib import gaierror

It works with import socket.

> then your try/except clause would be like:
>        except telnetlib.gaierror:

I can catch it now with socket.gaierror but I do not understand why
telnetlib does not raise an error instead. To me it would be more
logically that telnetlib catches this and raises an error. Now this
comes from a very novice programmer so I might be way off on this :-)

Another question, read_until can be passed a timeout. How would catch
if the timeout hit? It does not raise an error it afaics just returns
whatever it read till the timeout.

Thanks
Sander

From denis.spir at free.fr  Sun Dec 28 20:25:37 2008
From: denis.spir at free.fr (spir)
Date: Sun, 28 Dec 2008 20:25:37 +0100
Subject: [Tutor] telnetlib unable to cath gaierror
In-Reply-To: <20081228181730.GA74533@dragon.alchemy.com>
References: <b65fbb130812281009s38058791tb5ec6596ff2653dc@mail.gmail.com>
	<20081228181730.GA74533@dragon.alchemy.com>
Message-ID: <1230492337.6482.1.camel@o>

Le dimanche 28 d?cembre 2008 ? 10:17 -0800, Steve Willoughby a ?crit :
> On Sun, Dec 28, 2008 at 07:09:51PM +0100, Sander Sweers wrote:
> > I am having issues cathing exceptions from telnetlib. What I am doing is:
> > except gaierror:
> > Which gives me "NameError: name 'gaierror' is not defined" :-(
> 
> This error message contains your clue.  If the name you're referencing is not defined, you usually forgot to either explicitly import it, or to name it with its namespace attached.
> 
> So you either want to say:
> 
> 	from telnetlib import gaierror
> 
> at the top of your script, or if you earlier said simply "import telnetlib",
> 
> then your try/except clause would be like:
> 
> 	except telnetlib.gaierror:
> 
Well, actually, gaierror is an Exception of the socket module:

import telnetlib,socket
tc = telnetlib.Telnet()
try:
    tc.open("abc")
except socket.gaierror:
    print "Invalid hostname"
    raise

==>

spir at o:~/prog/parse$ python "___test.py"
Invalid hostname
Traceback (most recent call last):
  File "___test.py", line 6, in <module>
    tc.open("abc")
  File "/usr/lib/python2.5/telnetlib.py", line 225, in open
    for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
socket.gaierror: (-2, 'Name or service not known')

Denis


From Jaggojaggo+Py at gmail.com  Sun Dec 28 23:49:53 2008
From: Jaggojaggo+Py at gmail.com (Omer)
Date: Mon, 29 Dec 2008 00:49:53 +0200
Subject: [Tutor] Fwd: Class Extend Help
In-Reply-To: <f0b4202b0812230803u781d339fy14e10e5a96f27d79@mail.gmail.com>
References: <515008f10812200823mac79878yb872cb6a549c77db@mail.gmail.com>
	<f0b4202b0812200849k3ac5cd97sd45775c3e93ce7db@mail.gmail.com>
	<515008f10812220958y39399988k1fd2d080cb7b327b@mail.gmail.com>
	<515008f10812230631p348d3abdt949cdabc80c55acd@mail.gmail.com>
	<1c2a2c590812230723i336e8b3fo93c782d3dc0cdb57@mail.gmail.com>
	<f0b4202b0812230803u781d339fy14e10e5a96f27d79@mail.gmail.com>
Message-ID: <515008f10812281449k7367aa0ft3494e35a81966c28@mail.gmail.com>

Thx for help,
extreme lack of free time lately,
will look into it.

[Wouldn't've noticed myself that urlopen is not a class.]

On Tue, Dec 23, 2008 at 6:03 PM, Richard Lovely
<roadierich at googlemail.com>wrote:

> OK, going on Kent's post:
>
> from urllib import urlopen
>
> class fetch(object):
>    def __init__(self, *args):
>        self.response = urlopen(*args)
>        self.content = self.response.read()
>
>
> I forgot urlopen was a function.  It made sense in my head for it to
> be a class, instead of _returning_ a class.
>
> It's trying to call __init__ on a functionType instance, and it's
> getting confused.
>
> See http://dpaste.com/hold/101951/ for another example.  The error
> message is something cryptic, but between #python and I we think it's
> something to do with calling type().
> ---
> Richard "Roadie Rich" Lovely, part of the JNP|UK Famile
> www.theJNP.com
>
>
>
> 2008/12/23 Kent Johnson <kent37 at tds.net>:
> > On Tue, Dec 23, 2008 at 9:31 AM, Omer <Jaggojaggo+Py at gmail.com<Jaggojaggo%2BPy at gmail.com>>
> wrote:
> >
> >>>>> from urllib import urlopen
> >>>>> class fetch(urlopen):
> >> ...     def __init__(self,*args):
> >> ...         urlopen.__init__(self, *args)
> >> ...         self.content = self.read()
> >> ...
> >>
> >> Traceback (most recent call last):
> >>   File "<interactive input>", line 1, in <module>
> >> TypeError: Error when calling the metaclass bases
> >>     function() argument 1 must be code, not str
> >>
> >> Anybody, any idea what's up with that?
> >
> > That's pretty obscure, not sure why you get exactly that error!
> >
> > Anyway the code should be
> > class fetch(object):
> >
> > urlopen is a function, not a class, so it can't be a base class of
> > fetch. There is no need for it to be a base class, either; just use
> > object.
> >
> > Kent
> > _______________________________________________
> > Tutor maillist  -  Tutor at python.org
> > http://mail.python.org/mailman/listinfo/tutor
> >
>
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From david at abbottdavid.com  Mon Dec 29 02:41:17 2008
From: david at abbottdavid.com (David)
Date: Sun, 28 Dec 2008 20:41:17 -0500
Subject: [Tutor] Exception Handling
Message-ID: <49582ABD.2030906@abbottdavid.com>

Hi,
Is this the correct way to handle a ValueError exception and should I 
get in the practice of catching them? Also any suggestions on the program.
thanks
-david

-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From david at abbottdavid.com  Mon Dec 29 02:42:45 2008
From: david at abbottdavid.com (David)
Date: Sun, 28 Dec 2008 20:42:45 -0500
Subject: [Tutor] Exception Handling
In-Reply-To: <49582ABD.2030906@abbottdavid.com>
References: <49582ABD.2030906@abbottdavid.com>
Message-ID: <49582B15.7000108@abbottdavid.com>

David wrote:
> Hi,
> Is this the correct way to handle a ValueError exception and should I 
> get in the practice of catching them? Also any suggestions on the program.
> thanks
> -david
> 
Might help if I included the program :)

#!/usr/bin/python
import time

print "Enter year as 0000"
print "Enter month and day as 00"

while True:
     try:
         yr = int(raw_input("What year were you born? "))
         mn = int(raw_input("What month were you born? "))
         dy = int(raw_input("What day were you born? "))
         curr_date = time.strftime("%Y %m %d", time.gmtime())

         ynum = int(time.strftime("%Y", time.gmtime())) - int(yr)
         mnum = int(time.strftime("%m", time.gmtime()))
         dnum = int(time.strftime("%d", time.gmtime()))
         mn = int(mn)
         dy = int(dy)

         if mn - mnum:
             print "You are %i" % ynum, "years old."
             break
         elif mn == mnum and dy < dnum:
             print "You are %i" % ynum, "years old."
             break
         else:
             ret = int(ynum) - 1
             print "You are %i" % ret, "years old."
             break
     except ValueError:
         print "Oops, You must enter a number!"



-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From wormwood_3 at yahoo.com  Mon Dec 29 02:49:59 2008
From: wormwood_3 at yahoo.com (wormwood_3)
Date: Sun, 28 Dec 2008 17:49:59 -0800 (PST)
Subject: [Tutor] Printing the code of a function
Message-ID: <749311.18420.qm@web110812.mail.gq1.yahoo.com>

Hello all,

This might be trivially easy, but I was having a hard time searching on it since all the component terms are overloaded:-) I am wondering if there is a way to print out the code of a defined function. So if I have:

def foo():
    print "Show me the money."

then I would like to do something like:

>>> foo.show_code
def foo():
    print "Show me the money."

I checked out everything in dir(foo), but everything that looked promising (namely foo.func_code), didn't end up being anything close.

Thanks for any help!

Cordially,
Sam

 _______________________
Samuel Huckins


Homepage - http://samuelhuckins.com
Tech blog - http://dancingpenguinsoflight.com/
Photos - http://www.flickr.com/photos/samuelhuckins/
AIM - samushack | Gtalk - samushack | Skype - shuckins
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From motoom at xs4all.nl  Mon Dec 29 03:03:17 2008
From: motoom at xs4all.nl (Michiel Overtoom)
Date: Mon, 29 Dec 2008 03:03:17 +0100
Subject: [Tutor] Printing the code of a function
In-Reply-To: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
References: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
Message-ID: <49582FE5.2030607@xs4all.nl>


wormwood_3 wrote:

 > I am wondering if there is a way to
 > print out the code of a defined function.

When Python compiles source code, it doesn't store the source code 
itself; only the compiled intermediate code. With the 'dis' package you 
can disassemble that:

def foo():
     print "Show me the money."

import dis
dis.dis(foo)

 >>>
   2           0 LOAD_CONST               1 ('Show me the money.')
               3 PRINT_ITEM
               4 PRINT_NEWLINE
               5 LOAD_CONST               0 (None)
               8 RETURN_VALUE
 >>>


-- 
"The ability of the OSS process to collect and harness
the collective IQ of thousands of individuals across
the Internet is simply amazing." - Vinod Vallopillil
http://www.catb.org/~esr/halloween/halloween4.html

From bgailer at gmail.com  Mon Dec 29 03:07:12 2008
From: bgailer at gmail.com (bob gailer)
Date: Sun, 28 Dec 2008 21:07:12 -0500
Subject: [Tutor] Printing the code of a function
In-Reply-To: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
References: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
Message-ID: <495830D0.1030302@gmail.com>

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From bgailer at gmail.com  Mon Dec 29 03:13:41 2008
From: bgailer at gmail.com (bob gailer)
Date: Sun, 28 Dec 2008 21:13:41 -0500
Subject: [Tutor] Exception Handling
In-Reply-To: <49582B15.7000108@abbottdavid.com>
References: <49582ABD.2030906@abbottdavid.com>
	<49582B15.7000108@abbottdavid.com>
Message-ID: <49583255.7080507@gmail.com>

David wrote:
> David wrote:
>> Hi,
>> Is this the correct way to handle a ValueError exception and should I 
>> get in the practice of catching them? 

Well yes and no.

I think it is better to use the string method isdigit to test for digits 
only.

Also IMHO it is bad design to put a lot of code inside a try block. In 
this case the user might make a mistake on day and then is forced to 
reenter the year and month!

Better to write a function for requesting an integer from the user which 
loops until the user gets it right (with some way to escape if he gets 
frustrated and just wants to quit.

>> Also any suggestions on the program.
>> thanks
>> -david
>>
> Might help if I included the program :)
>
> #!/usr/bin/python
> import time
>
> print "Enter year as 0000"
> print "Enter month and day as 00"
>
> while True:
>     try:
>         yr = int(raw_input("What year were you born? "))
>         mn = int(raw_input("What month were you born? "))
>         dy = int(raw_input("What day were you born? "))
>         curr_date = time.strftime("%Y %m %d", time.gmtime())
>
>         ynum = int(time.strftime("%Y", time.gmtime())) - int(yr)
>         mnum = int(time.strftime("%m", time.gmtime()))
>         dnum = int(time.strftime("%d", time.gmtime()))
>         mn = int(mn)
>         dy = int(dy)
>
>         if mn - mnum:
>             print "You are %i" % ynum, "years old."
>             break
>         elif mn == mnum and dy < dnum:
>             print "You are %i" % ynum, "years old."
>             break
>         else:
>             ret = int(ynum) - 1
>             print "You are %i" % ret, "years old."
>             break
>     except ValueError:
>         print "Oops, You must enter a number!"
>
>
>


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From wormwood_3 at yahoo.com  Mon Dec 29 05:45:41 2008
From: wormwood_3 at yahoo.com (wormwood_3)
Date: Sun, 28 Dec 2008 20:45:41 -0800 (PST)
Subject: [Tutor] Printing the code of a function
References: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
	<495830D0.1030302@gmail.com>
Message-ID: <448325.4439.qm@web110802.mail.gq1.yahoo.com>

I actually didn't have a definite use case in mind, it was pure curiosity that arose while writing a few simple test functions. After having considered it more, I can't come up with a case where it would really be necessary, so I apologize for that. It makes sense why it wouldn't be possible without a disassembler now. Thanks for the info!

 _______________________
Samuel Huckins


Homepage - http://samuelhuckins.com
Tech blog - http://dancingpenguinsoflight.com/
Photos - http://www.flickr.com/photos/samuelhuckins/
AIM - samushack | Gtalk - samushack | Skype - shuckins




________________________________
From: bob gailer <bgailer at gmail.com>
To: wormwood_3 <wormwood_3 at yahoo.com>
Cc: tutor at python.org
Sent: Sunday, December 28, 2008 9:07:12 PM
Subject: Re: [Tutor] Printing the code of a function

wormwood_3 wrote: 
Hello
all,

This might be trivially easy, but I was having a hard time searching on
it since all the component terms are overloaded:-) I am wondering if
there is a way to print out the code of a defined function. 
Python does not store the source when compiling things. So the short
answer is NO.

There are some "disassemblers" for Python but I have no experience with
them. They will not be able to reconstruct the exact source.

But ... why do you want to do this? Perhaps if we had more information
about the "use case" we could steer you to a solution.


So
if I have:

def foo():
    print "Show me the money."

then I would like to do something like:

>>> foo.show_code
def foo():
    print "Show me the money."

I checked out everything in dir(foo), but everything that looked
promising (namely foo.func_code), didn't end up being anything close.

Thanks for any help!

Cordially,
Sam

 
_______________________
Samuel Huckins


Homepage - http://samuelhuckins.com
Tech blog - http://dancingpenguinsoflight.com/
Photos - http://www.flickr.com/photos/samuelhuckins/
AIM - samushack | Gtalk - samushack | Skype - shuckins 


________________________________

_______________________________________________
Tutor maillist  -  Tutor at python.org http://mail.python.org/mailman/listinfo/tutor 


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239
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From alan.gauld at btinternet.com  Mon Dec 29 10:02:29 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 29 Dec 2008 09:02:29 -0000
Subject: [Tutor] Exception Handling
References: <49582ABD.2030906@abbottdavid.com>
	<49582B15.7000108@abbottdavid.com>
Message-ID: <gja3n7$tp8$1@ger.gmane.org>


"David" <david at abbottdavid.com> wrote

>> Is this the correct way to handle a ValueError exception and should 
>> I get in the practice of catching them?

Yes and Yes.

Although I woulfd move the except clause up to just after the input 
section
(which is where the errors will be raised). A couple of other comments
below:

> while True:
>     try:
>         yr = int(raw_input("What year were you born? "))
>         mn = int(raw_input("What month were you born? "))
>         dy = int(raw_input("What day were you born? "))
>         curr_date = time.strftime("%Y %m %d", time.gmtime())
>
>         ynum = int(time.strftime("%Y", time.gmtime())) - int(yr)
>         mnum = int(time.strftime("%m", time.gmtime()))
>         dnum = int(time.strftime("%d", time.gmtime()))
>         mn = int(mn)
>         dy = int(dy)

Put the except here, its easier to see where the error came from.
And since the error message only applies to these int() calls its
more accurate.

>         if mn - mnum:
>             print "You are %i" % ynum, "years old."

This is an odd use of string formatting, more usually you
would only use one string:

             print "You are %i years old" % ynum

Either that or just insert the value and not use formattting:

             print "You are", ynum, "years old."

>         else:
>             ret = int(ynum) - 1

You don't need the int conversion here since yuou already
did it at the input stage. But...

>             print "You are %i" % ret, "years old."

Why not just

        print "You are %i" % ynum-1, "years old."

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Mon Dec 29 10:10:45 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 29 Dec 2008 09:10:45 -0000
Subject: [Tutor] Exception Handling
References: <49582ABD.2030906@abbottdavid.com><49582B15.7000108@abbottdavid.com>
	<49583255.7080507@gmail.com>
Message-ID: <gja46o$uv1$1@ger.gmane.org>


"bob gailer" <bgailer at gmail.com> wrote

> Also IMHO it is bad design to put a lot of code inside a try block. 
> In this case the user might make a mistake on day and then is forced 
> to reenter the year and month!

Obviously there is no absolute rule here but I disagree.
One of the biggest advantages of try/except error handling is
that it keeps the mess of handling errors out of the main logic
of the code. This has two effects:
1) Code that is much easier to read
2) a lot less error handling code

Using "big bite" try/except does mean the except clauses
become more complex if you want to find out exactly which
line caused the error, as in the example above, but it can
be done by examining the traceback, but in general I much
prefer to wrap logical blocks of code using try/except rather
than only one or two lines

> Better to write a function for requesting an integer from the user 
> which loops until the user gets it right (with some way to escape if 
> he gets frustrated and just wants to quit.

And this I agree with. If you do want to check each line use a 
function
that incorporates the checking within it and call that to get a 
guaranteed
result. And that keeps both Bob and I happy with the try/excepts
stylistically speaking :-)

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From alan.gauld at btinternet.com  Mon Dec 29 10:18:43 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 29 Dec 2008 09:18:43 -0000
Subject: [Tutor] Printing the code of a function
References: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
Message-ID: <gja4ll$ic$1@ger.gmane.org>


"wormwood_3" <wormwood_3 at yahoo.com> wrote

> I am wondering if there is a way to print out the code of a defined 
> function.

Its not reliable but I think you can use

func.func_code.filename
func.func_code.firstlineno

To find the first line of code in the original source file.
Its up to you to figure out the last line though! I guess checking
for the next line with equivalent indentation might work.

But I'm not sure how much good it would do you... unless you
were writing a debugger maybe?

Alan G



From prasadaraon50 at gmail.com  Mon Dec 29 16:40:32 2008
From: prasadaraon50 at gmail.com (prasad rao)
Date: Mon, 29 Dec 2008 07:40:32 -0800
Subject: [Tutor] optional parameter in list comprehension
Message-ID: <9e3fac840812290740vd6bfe0cu62987dc76acf2253@mail.gmail.com>

hello!    I am a novice looking up to the tutor as my Guide.
    I got a problem   while using optional parameter.

#! user/bin/env python
import os

def myfiles(directory,extension=None):
    for x in [os.path.join(x,i) for x,y,z in os.walk(directory)\
    for i in z if i.endswith(extension)]:print x

if __name__=='__main__':
  import sys
  myfiles(sys.argv[1],sys.argv[2])

>>> myfiles.myfiles('C:\\python26')

Traceback (most recent call last):
  File "<pyshell#17>", line 1, in <module>
    myfiles.myfiles('C:\\python26')
  File "C:\Python26\lib\site-packages\myfiles.py", line 6, in myfiles
    for i in z if i.endswith(extension)]:print x
TypeError: expected a character buffer object
>>> myfiles.myfiles('C:\\python26','doc')
C:\python26\Doc\examples.doc

How can I rectify this?

Thanks

Prasad
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From digitalxero at gmail.com  Mon Dec 29 16:43:24 2008
From: digitalxero at gmail.com (Dj Gilcrease)
Date: Mon, 29 Dec 2008 07:43:24 -0800
Subject: [Tutor] optional parameter in list comprehension
In-Reply-To: <9e3fac840812290740vd6bfe0cu62987dc76acf2253@mail.gmail.com>
References: <9e3fac840812290740vd6bfe0cu62987dc76acf2253@mail.gmail.com>
Message-ID: <e9764b730812290743p2aa3522ckb2cc0684178329f1@mail.gmail.com>

def myfiles(directory,extension=None):
    for x in [os.path.join(x,i) for x,y,z in os.walk(directory)\
    if extension:
        for i in z if i.endswith(extension)]:print x


Dj Gilcrease
OpenRPG Developer
~~http://www.openrpg.com

From bgailer at gmail.com  Mon Dec 29 16:56:20 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 29 Dec 2008 10:56:20 -0500
Subject: [Tutor] optional parameter in list comprehension
In-Reply-To: <e9764b730812290743p2aa3522ckb2cc0684178329f1@mail.gmail.com>
References: <9e3fac840812290740vd6bfe0cu62987dc76acf2253@mail.gmail.com>
	<e9764b730812290743p2aa3522ckb2cc0684178329f1@mail.gmail.com>
Message-ID: <4958F324.8010402@gmail.com>

Dj Gilcrease wrote:
> def myfiles(directory,extension=None):
>     for x in [os.path.join(x,i) for x,y,z in os.walk(directory)\
>     if extension: << SYNTAX ERROR!
>         for i in z if i.endswith(extension)]:print x
>
>   

-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From bgailer at gmail.com  Mon Dec 29 16:57:03 2008
From: bgailer at gmail.com (bob gailer)
Date: Mon, 29 Dec 2008 10:57:03 -0500
Subject: [Tutor] optional parameter in list comprehension
In-Reply-To: <9e3fac840812290740vd6bfe0cu62987dc76acf2253@mail.gmail.com>
References: <9e3fac840812290740vd6bfe0cu62987dc76acf2253@mail.gmail.com>
Message-ID: <4958F34F.8000006@gmail.com>

prasad rao wrote:
> hello!
>     I am a novice looking up to the tutor as my Guide.
>     I got a problem   while using optional parameter.
>
> #! user/bin/env python
> import os
>
> def myfiles(directory,extension=None):

change that to def myfiles(directory,extension=""):

>     for x in [os.path.join(x,i) for x,y,z in os.walk(directory)\
>     for i in z if i.endswith(extension)]:print x
>     
> if __name__=='__main__':
>   import sys
>   myfiles(sys.argv[1],sys.argv[2])
>
> >>> myfiles.myfiles('C:\\python26')
>
> Traceback (most recent call last):
>   File "<pyshell#17>", line 1, in <module>
>     myfiles.myfiles('C:\\python26')
>   File "C:\Python26\lib\site-packages\myfiles.py", line 6, in myfiles
>     for i in z if i.endswith(extension)]:print x
> TypeError: expected a character buffer object
> >>> myfiles.myfiles('C:\\python26','doc')
> C:\python26\Doc\examples.doc
>
> How can I rectify this?
>
> Thanks 
>
> Prasad
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>   


-- 
Bob Gailer
Chapel Hill NC 
919-636-4239


From denis.spir at free.fr  Mon Dec 29 16:57:44 2008
From: denis.spir at free.fr (spir)
Date: Mon, 29 Dec 2008 16:57:44 +0100
Subject: [Tutor] Exception Handling
In-Reply-To: <gja46o$uv1$1@ger.gmane.org>
References: <49582ABD.2030906@abbottdavid.com>
	<49582B15.7000108@abbottdavid.com> <49583255.7080507@gmail.com>
	<gja46o$uv1$1@ger.gmane.org>
Message-ID: <20081229165744.7a1e262c@o>

On Mon, 29 Dec 2008 09:10:45 -0000
"Alan Gauld" <alan.gauld at btinternet.com> wrote:

> 
> "bob gailer" <bgailer at gmail.com> wrote
> 
> > Also IMHO it is bad design to put a lot of code inside a try block. 
> > In this case the user might make a mistake on day and then is forced 
> > to reenter the year and month!
> 
> Obviously there is no absolute rule here but I disagree.
> One of the biggest advantages of try/except error handling is
> that it keeps the mess of handling errors out of the main logic
> of the code. This has two effects:
> 1) Code that is much easier to read
> 2) a lot less error handling code
> 
> Using "big bite" try/except does mean the except clauses
> become more complex if you want to find out exactly which
> line caused the error, as in the example above, but it can
> be done by examining the traceback, but in general I much
> prefer to wrap logical blocks of code using try/except rather
> than only one or two lines
 
I often use the else clause of try...except. This allows putting only the
minimum problematic code lines inside the try block, which is good both for
legibility andto avoid catching unexpected errors. The else will be executed
only in case of no exception:

try:
	problematic_instructions
except ExceptionType, exception:
	expected_exception_handler
else:
	further_standard_process

denis

------
la vida e estranya

From denis.spir at free.fr  Mon Dec 29 17:20:56 2008
From: denis.spir at free.fr (spir)
Date: Mon, 29 Dec 2008 17:20:56 +0100
Subject: [Tutor] Printing the code of a function
In-Reply-To: <gja4ll$ic$1@ger.gmane.org>
References: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
	<gja4ll$ic$1@ger.gmane.org>
Message-ID: <20081229172056.36ffbbb5@o>

On Mon, 29 Dec 2008 09:18:43 -0000
"Alan Gauld" <alan.gauld at btinternet.com> wrote:

> 
> "wormwood_3" <wormwood_3 at yahoo.com> wrote
> 
> > I am wondering if there is a way to print out the code of a defined 
> > function.
> 
> Its not reliable but I think you can use
> 
> func.func_code.filename
> func.func_code.firstlineno
> 
> To find the first line of code in the original source file.
> Its up to you to figure out the last line though! I guess checking
> for the next line with equivalent indentation might work.
> 
> But I'm not sure how much good it would do you... unless you
> were writing a debugger maybe?
> 
> Alan G

I would do it so by parsing source file:

* (convert indents to tabs (easier to parse))
* search for a line that start with (n indents) + "def func_name"
* record all following lines that start with (n+1 indents) or more
* stop where a line starts with (n indents) or less

denis

------
la vida e estranya

From kent37 at tds.net  Mon Dec 29 21:05:24 2008
From: kent37 at tds.net (Kent Johnson)
Date: Mon, 29 Dec 2008 15:05:24 -0500
Subject: [Tutor] Printing the code of a function
In-Reply-To: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
References: <749311.18420.qm@web110812.mail.gq1.yahoo.com>
Message-ID: <1c2a2c590812291205t57d8d26do7fc049accc4bab7b@mail.gmail.com>

On Sun, Dec 28, 2008 at 8:49 PM, wormwood_3 <wormwood_3 at yahoo.com> wrote:
> Hello all,
>
> This might be trivially easy, but I was having a hard time searching on it
> since all the component terms are overloaded:-) I am wondering if there is a
> way to print out the code of a defined function.

If the source code is available try inspect.getsource().

Kent

From eduardo.susan at gmail.com  Mon Dec 29 21:18:55 2008
From: eduardo.susan at gmail.com (Eduardo Vieira)
Date: Mon, 29 Dec 2008 13:18:55 -0700
Subject: [Tutor] Modifying a QIF
Message-ID: <9356b9f30812291218v4c64ea10o1969a164e38ae350@mail.gmail.com>

Hello, this weekend I had fun using Python for text processing. I
needed to change a qif converted from a ofx, using the tool MT2OFX
(http://www.xs4all.nl/~csmale/mt2ofx/en/index.htm)
I wanted to change transactions like these:
D11/14/2008
MCHEQUE 102 17590807;Cheque or Preauth. Debit
T-500.00
N102
^

Into this:
D11/14/2008
MCHEQUE 102 17590807;Cheque or Preauth. Debit
T-500.00
N102
PLorne Koehn
LHousing:Rent

== That is, insert those given Payee and Category if the transaction
was a cheque of 500.00

I came up with these two versions and would like to know which should
be more efficient or practical. Could you point improvements?
VERSION ONE:
f = open('cibc.QIF', 'r').readlines()
for line in range(len(f)):
    if f[line] == 'T-500.00\n':
        f[line+1] += 'PLorne Koehn\nLHousing:Rent\n'

new = open('cibc.QIF', 'w')
new.writelines(f)

VERSION TWO:
f = open('cibc.QIF', 'rw')
g = open('newresult.qif', 'w')
flag = 0
for line in f:
    if line == 'T-500.00\n':
        flag = 1
    elif line.startswith('N') and flag:
        flag = 0
        line += 'PLorne Koehn\nLHousing:Rent\n'

    g.write(line)

f.close()

#======

    One thing like about version 1 is that I can overwrite the same
file, and don't need to create another one. I haven't figured out how
to do the same with the second version and overcoming the IOError.

Thanks for your attention

Edu

From denis.spir at free.fr  Mon Dec 29 23:52:24 2008
From: denis.spir at free.fr (spir)
Date: Mon, 29 Dec 2008 23:52:24 +0100
Subject: [Tutor] Modifying a QIF
In-Reply-To: <9356b9f30812291218v4c64ea10o1969a164e38ae350@mail.gmail.com>
References: <9356b9f30812291218v4c64ea10o1969a164e38ae350@mail.gmail.com>
Message-ID: <20081229235224.09b0d3de@o>

On Mon, 29 Dec 2008 13:18:55 -0700
"Eduardo Vieira" <eduardo.susan at gmail.com> wrote:

> Hello, this weekend I had fun using Python for text processing. I
> needed to change a qif converted from a ofx, using the tool MT2OFX
> (http://www.xs4all.nl/~csmale/mt2ofx/en/index.htm)
> I wanted to change transactions like these:
> D11/14/2008
> MCHEQUE 102 17590807;Cheque or Preauth. Debit
> T-500.00
> N102
> ^
> 
> Into this:
> D11/14/2008
> MCHEQUE 102 17590807;Cheque or Preauth. Debit
> T-500.00
> N102
> PLorne Koehn
> LHousing:Rent
> 
> == That is, insert those given Payee and Category if the transaction
> was a cheque of 500.00
> 
> I came up with these two versions and would like to know which should
> be more efficient or practical. Could you point improvements?
> VERSION ONE:
> f = open('cibc.QIF', 'r').readlines()
> for line in range(len(f)):
>     if f[line] == 'T-500.00\n':
>         f[line+1] += 'PLorne Koehn\nLHousing:Rent\n'
> 
> new = open('cibc.QIF', 'w')
> new.writelines(f)
> 

I would change 'line' --> 'line_nr' or 'lineno'
or
for line,index in enumerate(f)
no!
for index,line in enumerate(f)
;-)

> VERSION TWO:
> f = open('cibc.QIF', 'rw')
> g = open('newresult.qif', 'w')
> flag = 0
> for line in f:
>     if line == 'T-500.00\n':
>         flag = 1
>     elif line.startswith('N') and flag:
>         flag = 0
>         line += 'PLorne Koehn\nLHousing:Rent\n'
> 
>     g.write(line)
> 
> f.close()
> 
> #======
> 
>     One thing like about version 1 is that I can overwrite the same
> file, and don't need to create another one. I haven't figured out how
> to do the same with the second version and overcoming the IOError.

maybe by first writing on a string instead directly to a file -- then flush the
whole text to the same file:

text = ""	# replaces g
...
text += line
...
f = open('cibc.QIF', 'w')
f.write(text)

> Thanks for your attention
> 
> Edu
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
> 


------
la vida e estranya

From alan.gauld at btinternet.com  Tue Dec 30 00:02:21 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Mon, 29 Dec 2008 23:02:21 -0000
Subject: [Tutor] Exception Handling
References: <49582ABD.2030906@abbottdavid.com><49582B15.7000108@abbottdavid.com>
	<49583255.7080507@gmail.com><gja46o$uv1$1@ger.gmane.org>
	<20081229165744.7a1e262c@o>
Message-ID: <gjbku0$chj$1@ger.gmane.org>

"spir" <denis.spir at free.fr> wrote

> I often use the else clause of try...except. This allows putting 
> only the
> minimum problematic code lines inside the try block, which is good 
> both for
> legibility andto avoid catching unexpected errors. The else will be 
> executed
> only in case of no exception:
>
> try:
> problematic_instructions
> except ExceptionType, exception:
> expected_exception_handler
> else:
> further_standard_process


Thats exactly what I try to avoid. The big win for me in try/except is
that I can put the whole logic of a function together with no error
code confusing the picture. The above is no better than the old
BASIC style error handling

problemInstruction
if errorcode == XXX:
    handle error
further instruction

I find that much harder to follow the normal case code than:

try:
    problematic instructions
    more instructions
    more problems
except Error1
    handleError1
except Error2:
    handleError2

Now I can see the real algorithm and the errors are all tiucked out of
the way at the bottom where I don't need to read them until its
necessary.

Assuming you don't wrte functions that are hundreds of lines long
that doesn't cause me any problerms when debugging but greatly
increases the readability

The only somewhat valid case for doing line by line exceptions is
IMHO the one that started this - where users are entering input
and would need to start right at the beginning in the event of an
error. But as Bob pointed out you can avoid that by writing
a convertion function to do the error handling and validation and
call it repeatedly.

But it is largely a matter of personal taste.

Alan G. 



From prasadaraon50 at gmail.com  Tue Dec 30 11:25:55 2008
From: prasadaraon50 at gmail.com (prasad rao)
Date: Tue, 30 Dec 2008 02:25:55 -0800
Subject: [Tutor] reply
Message-ID: <9e3fac840812300225m4e28b586k5014ce054f91f39d@mail.gmail.com>

Hello.       Thank you.Just a small change at the optional parameter made
all the
difference. It seems to be a mirracle.It is an enlitenment to me.
Thank you.
Prasad
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From lie.1296 at gmail.com  Tue Dec 30 13:59:36 2008
From: lie.1296 at gmail.com (Lie Ryan)
Date: Tue, 30 Dec 2008 12:59:36 +0000 (UTC)
Subject: [Tutor] Exception Handling
References: <49582ABD.2030906@abbottdavid.com>
	<49582B15.7000108@abbottdavid.com> <49583255.7080507@gmail.com>
	<gja46o$uv1$1@ger.gmane.org> <20081229165744.7a1e262c@o>
Message-ID: <gjd5vn$jc5$1@ger.gmane.org>

On Mon, 29 Dec 2008 16:57:44 +0100, spir wrote:

> On Mon, 29 Dec 2008 09:10:45 -0000
> "Alan Gauld" <alan.gauld at btinternet.com> wrote:
> 
> 
>> "bob gailer" <bgailer at gmail.com> wrote
>> 
>> > Also IMHO it is bad design to put a lot of code inside a try block.
>> > In this case the user might make a mistake on day and then is forced
>> > to reenter the year and month!
>> 
>> Obviously there is no absolute rule here but I disagree. One of the
>> biggest advantages of try/except error handling is that it keeps the
>> mess of handling errors out of the main logic of the code. This has two
>> effects:
>> 1) Code that is much easier to read
>> 2) a lot less error handling code
>> 
>> Using "big bite" try/except does mean the except clauses become more
>> complex if you want to find out exactly which line caused the error, as
>> in the example above, but it can be done by examining the traceback,
>> but in general I much prefer to wrap logical blocks of code using
>> try/except rather than only one or two lines
>  
> I often use the else clause of try...except. This allows putting only
> the minimum problematic code lines inside the try block, which is good
> both for legibility andto avoid catching unexpected errors. The else
> will be executed only in case of no exception:

I think it's better to put less in a try-clause so I'd rather not catch 
errors on the raw_input, and put validation code in a function, which I'd 
enclose in a try block, like this:

while True:
    yr = raw_input("What year were you born? ")
    mn = raw_input("What month were you born? ")
    dy = raw_input("What day were you born? ")
    
    try:
        date = is_valid_date(yr, mn, dy)
    except InvalidDate, e:
        # e might contain input not a number, or there is no 31 february
        print 'You entered an Invalid Date: ', e
    else:
        do_things(date)

Also, I'd rather ask for the dates in one raw_input, cuts much of the 
mess for the user (although it's a bit of extra codes)


From norman at khine.net  Tue Dec 30 15:32:38 2008
From: norman at khine.net (Norman Khine)
Date: Tue, 30 Dec 2008 15:32:38 +0100
Subject: [Tutor] optimize code
Message-ID: <495A3106.8040105@khine.net>

Hello,
I have this piece of code which I would like to further streamline it.

http://paste.lisp.org/display/72830

More specifically, I feel there is too many if statements.

What the code does is that it takes a form value and builds a dictionary

http://localhost/;search?level1=air-brokers-or-charters

returns

{'root_title': u'Expert Travel', 'here_title': 'Air brokers/air 
charter', 'country': 'UK'}

http://localhost/;search?level1=air-brokers-or-charters&level2=East+Anglia

returns

{'root_title': u'Expert Travel', 'level2': 'East Anglia', 'here_title': 
'Air brokers/air charter', 'country': 'UK'}


etc..

Thanks

Norman





From kent37 at tds.net  Tue Dec 30 16:04:00 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 30 Dec 2008 10:04:00 -0500
Subject: [Tutor] optimize code
In-Reply-To: <495A3106.8040105@khine.net>
References: <495A3106.8040105@khine.net>
Message-ID: <1c2a2c590812300704n618f6665o19facfaf6a6905d1@mail.gmail.com>

On Tue, Dec 30, 2008 at 9:32 AM, Norman Khine <norman at khine.net> wrote:
> Hello,
> I have this piece of code which I would like to further streamline it.

There is no need to re-create the mapping at each level of if; you can
just add new key/value pairs. For example
                    if level2 is not None:
                        mapping['level2'] = level2

> What the code does is that it takes a form value and builds a dictionary

It seems that the you are really returning a string, or at least
building a string to pass to gettext(). I would have each if statement
just append to the string. That would consolidate the return
statements. For example, if value is the string being built,
                    if level2 is not None:
                        value = '%s: %s' % (value, level2)

Kent

From norman at khine.net  Tue Dec 30 16:56:32 2008
From: norman at khine.net (Norman Khine)
Date: Tue, 30 Dec 2008 16:56:32 +0100
Subject: [Tutor] optimize code
In-Reply-To: <1c2a2c590812300704n618f6665o19facfaf6a6905d1@mail.gmail.com>
References: <495A3106.8040105@khine.net>
	<1c2a2c590812300704n618f6665o19facfaf6a6905d1@mail.gmail.com>
Message-ID: <495A44B0.9090806@khine.net>



Kent Johnson wrote:
> On Tue, Dec 30, 2008 at 9:32 AM, Norman Khine <norman at khine.net> wrote:
>> Hello,
>> I have this piece of code which I would like to further streamline it.
> 
> There is no need to re-create the mapping at each level of if; you can
> just add new key/value pairs. For example
>                     if level2 is not None:
>                         mapping['level2'] = level2
> 
>> What the code does is that it takes a form value and builds a dictionary
> 
> It seems that the you are really returning a string, or at least
> building a string to pass to gettext(). I would have each if statement
> just append to the string. That would consolidate the return
> statements. For example, if value is the string being built,
>                     if level2 is not None:
>                         value = '%s: %s' % (value, level2)

Thanks, it is very helpful.

Norman

From yodaalmighty2000 at gmail.com  Tue Dec 30 18:05:29 2008
From: yodaalmighty2000 at gmail.com (Pearce Michal)
Date: Tue, 30 Dec 2008 12:05:29 -0500
Subject: [Tutor] IDLE problems
Message-ID: <77d9eeef0812300905l2dbae2cdrf5c4729e3cda94a0@mail.gmail.com>

ok, so I just started working with python, however I have been working with
Java for awhile, and am fairly familiar with it. my problem with Python is
for the IDLE editor, and it is this: the return key, or enter key not only
moves the editor to the next line, but also executes the script. so if I
tried to enter a line like:

x = input("enter a value: ")
if x == 1:
     print "you entered one"
elif x == 2:
     print "you entered two"
elif x == 3:
     print "you entered three"

after I entered the line " x = input("enter a value: ") and ask "enter a
value: " I would type a number, and the script would end.

basically, I am wondering if there is a way to make it not execute when you
press return. I looked through the options, and it said the F5 key is what
executes the script, (but I am on a laptop, so pressing F5 turns up the
volume)


anyway, please help!
thanking to you in advance,

Yoda Almighty.
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From kent37 at tds.net  Tue Dec 30 19:04:49 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 30 Dec 2008 13:04:49 -0500
Subject: [Tutor] IDLE problems
In-Reply-To: <77d9eeef0812300905l2dbae2cdrf5c4729e3cda94a0@mail.gmail.com>
References: <77d9eeef0812300905l2dbae2cdrf5c4729e3cda94a0@mail.gmail.com>
Message-ID: <1c2a2c590812301004g5df08e81sa7f59b25bda1877f@mail.gmail.com>

On Tue, Dec 30, 2008 at 12:05 PM, Pearce Michal
<yodaalmighty2000 at gmail.com> wrote:
> ok, so I just started working with python, however I have been working with
> Java for awhile, and am fairly familiar with it. my problem with Python is
> for the IDLE editor, and it is this: the return key, or enter key not only
> moves the editor to the next line, but also executes the script.

IDLE has two kinds of windows - a shell window, which executes
commands as they are typed, and an editor window. The shell window is
handy for interactive exploration but, as you discovered, pretty
useless for creating a real program.

File / New Window will open an editor window that behaves the way you want.

Kent

From norman at khine.net  Tue Dec 30 21:42:00 2008
From: norman at khine.net (Norman Khine)
Date: Tue, 30 Dec 2008 21:42:00 +0100
Subject: [Tutor] optimize code
In-Reply-To: <1c2a2c590812300704n618f6665o19facfaf6a6905d1@mail.gmail.com>
References: <495A3106.8040105@khine.net>
	<1c2a2c590812300704n618f6665o19facfaf6a6905d1@mail.gmail.com>
Message-ID: <495A8798.5040402@khine.net>

Hi,
I have an updated version at http://paste.lisp.org/display/72843
Thanks for the advice, the code is much smaller and leaner than the 
first attempt.
Norman

Kent Johnson wrote:
> On Tue, Dec 30, 2008 at 9:32 AM, Norman Khine <norman at khine.net> wrote:
>> Hello,
>> I have this piece of code which I would like to further streamline it.
> 
> There is no need to re-create the mapping at each level of if; you can
> just add new key/value pairs. For example
>                     if level2 is not None:
>                         mapping['level2'] = level2
> 
>> What the code does is that it takes a form value and builds a dictionary
> 
> It seems that the you are really returning a string, or at least
> building a string to pass to gettext(). I would have each if statement
> just append to the string. That would consolidate the return
> statements. For example, if value is the string being built,
>                     if level2 is not None:
>                         value = '%s: %s' % (value, level2)
> 
> Kent
> 

From david at abbottdavid.com  Tue Dec 30 22:33:02 2008
From: david at abbottdavid.com (David)
Date: Tue, 30 Dec 2008 16:33:02 -0500
Subject: [Tutor] Exception Handling
Message-ID: <495A938E.1020509@abbottdavid.com>

> On Mon, 29 Dec 2008 16:57:44 +0100, spir wrote:
> 
>> > On Mon, 29 Dec 2008 09:10:45 -0000
>> > "Alan Gauld" <alan.gauld at btinternet.com> wrote:
>> > 
>> > 
>>> >> "bob gailer" <bgailer at gmail.com> wrote
>>> >> 
>>>> >> > Also IMHO it is bad design to put a lot of code inside a try block.
>>>> >> > In this case the user might make a mistake on day and then is forced
>>>> >> > to reenter the year and month!
>>> >> 
>>> >> Obviously there is no absolute rule here but I disagree. One of the
>>> >> biggest advantages of try/except error handling is that it keeps the
>>> >> mess of handling errors out of the main logic of the code. This has two
>>> >> effects:
>>> >> 1) Code that is much easier to read
>>> >> 2) a lot less error handling code
> Also, I'd rather ask for the dates in one raw_input, cuts much of the 
> mess for the user (although it's a bit of extra codes)
Thank you all for the tips. Next to do is to get the dates in one 
raw_input with the correct format and to check for a valid year, month, 
and day. Here is what I have now;
#!/usr/bin/python
import time

curr_date = time.strftime("%Y %m %d", time.gmtime())
print "Please enter the date format as: ", curr_date

while True:
     yr = raw_input("\nWhat year were you born? ")
     mn = raw_input("What month were you born? ")
     dy = raw_input("What day were you born? ")
     try:
         ynum = int(time.strftime("%Y", time.gmtime())) - int(yr)
         mnum = int(time.strftime("%m", time.gmtime()))
         dnum = int(time.strftime("%d", time.gmtime()))
     except ValueError:
         print "Oops, You must enter a number!"
     else:
         mn = int(mn)
         dy = int(dy)

         if mn <= mnum:
             print "You are", ynum, "years old."
             break
         elif mn == mnum and dy < dnum:
             print "You are", ynum, "years old."
             break
         else:
             ret = int(ynum) - 1
             print "You are", ret, "years old."
             break


-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From jervisau at gmail.com  Tue Dec 30 23:12:09 2008
From: jervisau at gmail.com (Jervis Whitley)
Date: Wed, 31 Dec 2008 09:12:09 +1100
Subject: [Tutor] Exception Handling
In-Reply-To: <495A938E.1020509@abbottdavid.com>
References: <495A938E.1020509@abbottdavid.com>
Message-ID: <8e63a5ce0812301412i3dfa74bchfd60fc40ab625a2f@mail.gmail.com>

On Wed, Dec 31, 2008 at 8:33 AM, David <david at abbottdavid.com> wrote:

>  On Mon, 29 Dec 2008 16:57:44 +0100, spir wrote:
>>
>>  > On Mon, 29 Dec 2008 09:10:45 -0000
>>> > "Alan Gauld" <alan.gauld at btinternet.com> wrote:
>>> > >
>>>
>>>> >> "bob gailer" <bgailer at gmail.com> wrote
>>>> >>
>>>>
>>>>> >> > Also IMHO it is bad design to put a lot of code inside a try
>>>>> block.
>>>>> >> > In this case the user might make a mistake on day and then is
>>>>> forced
>>>>> >> > to reenter the year and month!
>>>>>
>>>> >> >> Obviously there is no absolute rule here but I disagree. One of
>>>> the
>>>> >> biggest advantages of try/except error handling is that it keeps the
>>>> >> mess of handling errors out of the main logic of the code. This has
>>>> two
>>>> >> effects:
>>>> >> 1) Code that is much easier to read
>>>> >> 2) a lot less error handling code
>>>>
>>> Also, I'd rather ask for the dates in one raw_input, cuts much of the
>> mess for the user (although it's a bit of extra codes)
>>
> Thank you all for the tips. Next to do is to get the dates in one raw_input
> with the correct format and to check for a valid year, month, and day. Here
> is what I have now;
> #!/usr/bin/python
> import time
>
> curr_date = time.strftime("%Y %m %d", time.gmtime())
> print "Please enter the date format as: ", curr_date
>
> while True:
>    yr = raw_input("\nWhat year were you born? ")
>    mn = raw_input("What month were you born? ")
>    dy = raw_input("What day were you born? ")
>    try:
>        ynum = int(time.strftime("%Y", time.gmtime())) - int(yr)
>        mnum = int(time.strftime("%m", time.gmtime()))
>        dnum = int(time.strftime("%d", time.gmtime()))
>    except ValueError:
>        print "Oops, You must enter a number!"
>    else:
>        mn = int(mn)
>        dy = int(dy)
>
>        if mn <= mnum:
>            print "You are", ynum, "years old."
>            break
>        elif mn == mnum and dy < dnum:
>            print "You are", ynum, "years old."
>            break
>        else:
>            ret = int(ynum) - 1
>            print "You are", ret, "years old."
>            break
>
>
> --
> Powered by Gentoo GNU/LINUX
> http://www.linuxcrazy.com
> pgp.mit.edu
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>

Hi David,

If the user enters incorrect data for the month or day, a ValueError will
still be raised
on the conversion to integer.

I suggest that you wrap your request for user information in a function that
does the checking
for you. You can re-use this function for each piece of integer information
you require from the user.

example:

import time


class BadUserError(Exception):
    pass

def get_integer(retrieve, question, attempts=3):
    """
    A small function to attempt to retrieve
    information from a user, given a prompt question.

    retrive - any function that will accept a string as an argument
                and return a string or otherwise response from the user.
    question - a string type question that you would like to ask the user to
                respond to.
    attempts[optional] - how many times the user can incorrectly
                        enter data before the BadUserError is raised.
    """

    while attempts > 0:
        num = retrieve(question)
        try:
            # try casting the user input as an integer.
            return int(num)
        except ValueError:
            print "Oops, You must enter a number!"

        attempts -= 1
    raise BadUserError("Too many incorrect tries!")

curr_date = time.strftime("%Y %m %d", time.gmtime())
print "Please enter the date format as: ", curr_date


yr = get_integer(raw_input, "\nWhat year were you born? ")
mn = get_integer(raw_input, "What month were you born? ")
dy = get_integer(raw_input, "What day were you born? ")

today = time.gmtime()

ynum = today.tm_year - yr
mnum = today.tm_mon
dnum = today.tm_mday

if mn <= mnum:
    print "You are", ynum, "years old."
elif mn == mnum and dy < dnum:
    print "You are", ynum, "years old."
else:
    ret = int(ynum) - 1
    print "You are", ret, "years old."
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From kent37 at tds.net  Tue Dec 30 23:23:42 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 30 Dec 2008 17:23:42 -0500
Subject: [Tutor] optimize code
In-Reply-To: <495A8798.5040402@khine.net>
References: <495A3106.8040105@khine.net>
	<1c2a2c590812300704n618f6665o19facfaf6a6905d1@mail.gmail.com>
	<495A8798.5040402@khine.net>
Message-ID: <1c2a2c590812301423p758d389dpb60aba74e643d447@mail.gmail.com>

On Tue, Dec 30, 2008 at 3:42 PM, Norman Khine <norman at khine.net> wrote:
> Hi,
> I have an updated version at http://paste.lisp.org/display/72843
> Thanks for the advice, the code is much smaller and leaner than the first
> attempt.

The level2-4 code could all be consolidated into a loop:

for levelName in 'level2 level3 level4'.split():
  level = context.get_form_value(levelName)
  if level is None: break
  title = '%s: %s' % (title, level)

Kent

From kent37 at tds.net  Tue Dec 30 23:29:22 2008
From: kent37 at tds.net (Kent Johnson)
Date: Tue, 30 Dec 2008 17:29:22 -0500
Subject: [Tutor] Exception Handling
In-Reply-To: <495A938E.1020509@abbottdavid.com>
References: <495A938E.1020509@abbottdavid.com>
Message-ID: <1c2a2c590812301429w76745713rbbd15a520e8315cf@mail.gmail.com>

On Tue, Dec 30, 2008 at 4:33 PM, David <david at abbottdavid.com> wrote:
> Thank you all for the tips. Next to do is to get the dates in one raw_input
> with the correct format and to check for a valid year, month, and day. Here
> is what I have now;

>        ynum = int(time.strftime("%Y", time.gmtime())) - int(yr)
>        mnum = int(time.strftime("%m", time.gmtime()))
>        dnum = int(time.strftime("%d", time.gmtime()))

Yikes! How about time.gmtime().tm_year, etc, instead of all the calls
to strftime() and int()? And you might want to put the value of
time.gmtime() in a variable so you always use the same value, just in
case someone runs your program on New Year's Eve at midnight.

You might also want to look at the datetime module, in particular
datetime.timedelta.

Kent

From david at abbottdavid.com  Wed Dec 31 01:18:47 2008
From: david at abbottdavid.com (David)
Date: Tue, 30 Dec 2008 19:18:47 -0500
Subject: [Tutor] Exception Handling
In-Reply-To: <8e63a5ce0812301412i3dfa74bchfd60fc40ab625a2f@mail.gmail.com>
References: <495A938E.1020509@abbottdavid.com>
	<8e63a5ce0812301412i3dfa74bchfd60fc40ab625a2f@mail.gmail.com>
Message-ID: <495ABA67.9020706@abbottdavid.com>

Jervis Whitley wrote:
> 
> 
> On Wed, Dec 31, 2008 at 8:33 AM, David <david at abbottdavid.com 
> <mailto:david at abbottdavid.com>> wrote:
> 
>         On Mon, 29 Dec 2008 16:57:44 +0100, spir wrote:
> 
>              > On Mon, 29 Dec 2008 09:10:45 -0000
>              > "Alan Gauld" <alan.gauld at btinternet.com
>             <mailto:alan.gauld at btinternet.com>> wrote:
>              > >
> 
>                  >> "bob gailer" <bgailer at gmail.com
>                 <mailto:bgailer at gmail.com>> wrote
>                  >>

> Hi David,
> 
> If the user enters incorrect data for the month or day, a ValueError 
> will still be raised 
> on the conversion to integer.
> 
> I suggest that you wrap your request for user information in a function 
> that does the checking
> for you. You can re-use this function for each piece of integer 
> information you require from the user.
> 
> example:
> 
> import time
> 
> 
> class BadUserError(Exception):
>     pass
> 
> def get_integer(retrieve, question, attempts=3):
>     """ 
>     A small function to attempt to retrieve 
>     information from a user, given a prompt question.
> 
>     retrive - any function that will accept a string as an argument
>                 and return a string or otherwise response from the user.
>     question - a string type question that you would like to ask the user to
>                 respond to.
>     attempts[optional] - how many times the user can incorrectly
>                         enter data before the BadUserError is raised.
>     """
> 
>     while attempts > 0:
>         num = retrieve(question)
>         try:
>             # try casting the user input as an integer.
>             return int(num)
>         except ValueError:
>             print "Oops, You must enter a number!"
> 
>         attempts -= 1
>     raise BadUserError("Too many incorrect tries!") 
>

WOW, thanks Jervis, I had to edit some of my mistakes to get it to work 
right if your birthday is today. I also looked at tm_year, tm_mon, and 
tm_day. I still need to get it to prduce an error if the year is 0 or 
2009, the month is 0 or 13 and the day is 0 or 32.
david [06:56 PM] opteron ~ $ ./py_get_age.py
Please enter the date format as:  2008 12 30

What year were you born? 2010
What month were you born? 14
What day were you born? 34
You are -3 years old.

Here is a link to the current program;
http://dwabbott.com/code/
Thanks again everyone,
-david


-- 
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu


From jervisau at gmail.com  Wed Dec 31 01:37:52 2008
From: jervisau at gmail.com (Jervis Whitley)
Date: Wed, 31 Dec 2008 11:37:52 +1100
Subject: [Tutor] Exception Handling
In-Reply-To: <495ABA67.9020706@abbottdavid.com>
References: <495A938E.1020509@abbottdavid.com>
	<8e63a5ce0812301412i3dfa74bchfd60fc40ab625a2f@mail.gmail.com>
	<495ABA67.9020706@abbottdavid.com>
Message-ID: <8e63a5ce0812301637g64f048d3k349e961b511e8ed1@mail.gmail.com>

On Wed, Dec 31, 2008 at 11:18 AM, David <david at abbottdavid.com> wrote:

>
> . I still need to get it to prduce an error if the year is 0 or 2009, the
> month is 0 or 13 and the day is 0 or 32.


Try using the datetime module to check validity of entered data.

example:
>>> import datetime

>>> datetime.datetime(2008, 12, 32) # should be an error, there are only 31
days in December!
ValueError: day is out of range for month




> david [06:56 PM] opteron ~ $ ./py_get_age.py
> Please enter the date format as:  2008 12 30
>
> What year were you born? 2010
> What month were you born? 14
> What day were you born? 34
> You are -3 years old.


You can also use it to check if the input is in the future.

>>> userdate = datetime.datetime(2010, 1, 1)
>>> datetime.datetime.now() > userdate # a check to see if userdate is in
the past.
False

Cheers,

Jervis
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From sdragon1984 at gmail.com  Wed Dec 31 08:22:14 2008
From: sdragon1984 at gmail.com (nathan virgil)
Date: Wed, 31 Dec 2008 02:22:14 -0500
Subject: [Tutor] Creating sub-menus?
Message-ID: <111a9ddb0812302322sdef57daxb3639ff57ef326ab@mail.gmail.com>

I was reading the Non-Programmer's Tutorial for Python, and became really
proud of myself when I realized I could create a menu for functions. I
decided to try to take this one step further and see if I could create not
just a menu, but a menu with <i>sub</i>-menus, too! Ultimately, the idea I
came up with is this:

Each menu is a function that prints out options, saves a raw_input as the
variable choice, and returns choice. In the main menu, each option leads to
a sub-menu. After choice is defined, however, the sub-menu "tags" the value
of choice. Each sub-menu has it's own "tag", so that the program can tell
the first choice of sub-menu A from the first choice of sub-menu B. A
sub-menu function would end with code similar to:

choice = raw_input("What's your choice?")
choice = "a" + choice
return choice

Once I get all the menus and other functions out of the way, I get to the
part of the code that actually chooses which function to run. Here, I start
out with:

choice = "start"
current_menu = main_menu()

Then create a loop of while choice !=q, run current_menu, and include a
bunch of statements along the lines of:

if choice == <value that leads to first sub-menu>:
        current_menu = <function name for first sub-menu>
elif choice == <value that leads to first non-menu function>
        <first non-menu function>

This seems like it would work, but for some reason, every time I run the
code, it freezes after I give input from the main menu. Can anybody help? I
can show my source code, but indentation doesn't seem to copy/paste very
well, so it may be a bit hard to read...
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From alan.gauld at btinternet.com  Wed Dec 31 10:10:45 2008
From: alan.gauld at btinternet.com (Alan Gauld)
Date: Wed, 31 Dec 2008 09:10:45 -0000
Subject: [Tutor] Creating sub-menus?
References: <111a9ddb0812302322sdef57daxb3639ff57ef326ab@mail.gmail.com>
Message-ID: <gjfcup$b8j$1@ger.gmane.org>

"nathan virgil" <sdragon1984 at gmail.com> wrote

> Each menu is a function that prints out options, saves a raw_input 
> as the
> variable choice, and returns choice. In the main menu, each option 
> leads to
> a sub-menu. After choice is defined, however, the sub-menu "tags" 
> the value
> of choice.

Yes that can all work.

> Then create a loop of while choice !=q, run current_menu, and 
> include a
> bunch of statements along the lines of:
>
> if choice == <value that leads to first sub-menu>:
>        current_menu = <function name for first sub-menu>

Consider using a dictionary keyed by your combined choice values.
Then the big if/elif chain shrinks to

returnValue = FuncDict[choice](params)

The only challenge with this route is making all the functions
take a single input argument. But that argument can be a tuple :-)

> This seems like it would work, but for some reason, every time I run 
> the
> code, it freezes after I give input from the main menu. Can anybody 
> help? I
> can show my source code, but indentation doesn't seem to copy/paste 
> very
> well, so it may be a bit hard to read...

Try putting it on the pastebin web site and sending us the URL.
That gives us colour coding of syntax too which helps read it!

HTH

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld 



From kent37 at tds.net  Wed Dec 31 14:05:39 2008
From: kent37 at tds.net (Kent Johnson)
Date: Wed, 31 Dec 2008 08:05:39 -0500
Subject: [Tutor] Creating sub-menus?
In-Reply-To: <111a9ddb0812302322sdef57daxb3639ff57ef326ab@mail.gmail.com>
References: <111a9ddb0812302322sdef57daxb3639ff57ef326ab@mail.gmail.com>
Message-ID: <1c2a2c590812310505g75f3daddj1171384c16ec391a@mail.gmail.com>

On Wed, Dec 31, 2008 at 2:22 AM, nathan virgil <sdragon1984 at gmail.com> wrote:
> I was reading the Non-Programmer's Tutorial for Python, and became really
> proud of myself when I realized I could create a menu for functions. I
> decided to try to take this one step further and see if I could create not
> just a menu, but a menu with <i>sub</i>-menus, too! Ultimately, the idea I
> came up with is this:
>
> Each menu is a function that prints out options, saves a raw_input as the
> variable choice, and returns choice. In the main menu, each option leads to
> a sub-menu. After choice is defined, however, the sub-menu "tags" the value
> of choice. Each sub-menu has it's own "tag", so that the program can tell
> the first choice of sub-menu A from the first choice of sub-menu B. A
> sub-menu function would end with code similar to:
>
> choice = raw_input("What's your choice?")
> choice = "a" + choice
> return choice
>
> Once I get all the menus and other functions out of the way, I get to the
> part of the code that actually chooses which function to run. Here, I start
> out with:
>
> choice = "start"
> current_menu = main_menu()
>
> Then create a loop of while choice !=q, run current_menu, and include a
> bunch of statements along the lines of:
>
> if choice == <value that leads to first sub-menu>:
>         current_menu = <function name for first sub-menu>
> elif choice == <value that leads to first non-menu function>
>         <first non-menu function>

You might want to look at the cmd module in the std lib, either as
something to build on or an example of dispatching commands:
http://docs.python.org/library/cmd.html

cmd uses introspection to dispatch to commands, rather than if/elif or
a hand-build dispatch dict.

There are a couple of enhancements to cmd, also:
http://catherine.devlin.googlepages.com/cmd2.html
http://code.google.com/p/cmdln/

HTH,
Kent