From faassen@vet.uu.nl  Thu Nov  1 23:34:41 2001
From: faassen@vet.uu.nl (Martijn Faassen)
Date: Fri, 2 Nov 2001 00:34:41 +0100
Subject: [Edu-sig] How to Improve code performance
In-Reply-To: <3BDF2778.D27942E1@fa.disney.com>
References: <3BDF2778.D27942E1@fa.disney.com>
Message-ID: <20011102003441.A5952@vet.uu.nl>

Brent Burley wrote:
[snip]
> The big problem is that tab=tab+"..." in a loop is expensive since
> Python must allocate a new string and copy the old one each time.  The
> running time will increase with the square of the number of records,
> i.e. O(n*n).
> 
> It may not be intuitive, but putting all the partial strings in a list
> and then joining them at the end is more efficient as the running time
> will increase only linearly with the number of records, i.e. O(n).

An alternative is to use StringIO (or cStringIO if you're not dealing
with unicode strings):

> tab = []
> tab.append("<table align='center' border='1'>\n")
> for x in result:
>   tab.append("<tr>")
>   for y in x:
>     tab.extend(("<td>",y,"</td>\n"))
>   tab.append("</tr>")
> tab.append("</table>")
> print string.join(tab, "")

from StringIO import StringIO # from cStringIO import StringIO

result = StringIO()
result.write('<table align="center" border="1">\n')
for x in result:
    result.write("<tr>")
    for y in x:
        result.write("<td>")
        result.write(y)
        result.write("</td>\n")
    result.write("</tr>")
result.write("</table>")
print result.getvalue()

For an extra speedboost you could do this on top:

write = result.write

and then you can just use:

write("<tr">)

and so on.

I believe cStringIO can be even faster than the .join() operation,
but I haven't timed it.

Regards,

Martijn



From Brent.Burley@disney.com  Thu Nov  1 23:59:10 2001
From: Brent.Burley@disney.com (Brent Burley)
Date: Thu, 01 Nov 2001 15:59:10 -0800
Subject: [Edu-sig] How to Improve code performance
References: <3BDF2778.D27942E1@fa.disney.com> <20011102003441.A5952@vet.uu.nl>
Message-ID: <3BE1E1CE.7928DF0@fa.disney.com>

Thanks for the input - I hadn't really thought about StringIO.  Now that
I've taken a look ...

StringIO is no different than what I've shown - it appends each string
to a list and then uses string.join to build the final result.  There's
also additional overhead since it must support random access file
operations.

cStringIO should be faster, but it might not be.  It allocates a single
string buffer and reallocates it to be larger whenever it runs out of
room (doubling the previous size).  You end up reallocating and copying
the string log2(n) times.  If you were building a very large string, the
difference could be significant.

	Brent

Martijn Faassen wrote:
> 
> Brent Burley wrote:
> [snip]
> > The big problem is that tab=tab+"..." in a loop is expensive since
> > Python must allocate a new string and copy the old one each time.  The
> > running time will increase with the square of the number of records,
> > i.e. O(n*n).
> >
> > It may not be intuitive, but putting all the partial strings in a list
> > and then joining them at the end is more efficient as the running time
> > will increase only linearly with the number of records, i.e. O(n).
> 
> An alternative is to use StringIO (or cStringIO if you're not dealing
> with unicode strings):
> 
> I believe cStringIO can be even faster than the .join() operation,
> but I haven't timed it.


From deliberatus@my995internet.com  Thu Nov  8 18:52:22 2001
From: deliberatus@my995internet.com (Kirk Bailey)
Date: Thu, 08 Nov 2001 13:52:22 -0500
Subject: [Edu-sig] Just signed up
Message-ID: <3BEAD466.708B5497@my995internet.com>

for the list, I want to learn python and write a few things. Even
willing later to help people learn it. Tried banging my poor head
against perl for a spell, all I got was camel cooties...

-- 
Respectfully,
             -Kirk D Bailey (C)2001
              Addme! icq #27840081
end
      My Sites:
      http://www.howlermonkey.net/ - free REAL email! list service soon!
      http://www.sacredelectron.org/ - Rants! Spleenvents!
      http://www.minorfish.org/ - The list server for some of us!


From dyoo@hkn.eecs.berkeley.edu  Thu Nov  8 20:48:31 2001
From: dyoo@hkn.eecs.berkeley.edu (Danny Yoo)
Date: Thu, 8 Nov 2001 12:48:31 -0800 (PST)
Subject: [Edu-sig] Just signed up
In-Reply-To: <3BEAD466.708B5497@my995internet.com>
Message-ID: <Pine.LNX.4.21.0111081240590.10140-100000@hkn.eecs.berkeley.edu>

On Thu, 8 Nov 2001, Kirk Bailey wrote:

> for the list, I want to learn python and write a few things. Even
> willing later to help people learn it. Tried banging my poor head
> against perl for a spell, all I got was camel cooties...

Hi Kirk,

Welcome!  There's a section on Python.org for newcomers to the Python
language:

    http://python.org/doc/Newbies.html

and it has quite a few tutorials there that you can look at.


The Edu-sig mailing list is for educational issues, such as school
curricula and the Computer Programming For Everyone (CP4E) project; it
might not be the best place to ask "newbie" questions on Python.  
Instead, you may find the Tutor mailing list a good place to ask
questions:

    http://mail.python.org/mailman/listinfo/tutor


Best of wishes to you.



From wilson@visi.com  Thu Nov 15 02:49:17 2001
From: wilson@visi.com (Timothy Wilson)
Date: Wed, 14 Nov 2001 20:49:17 -0600 (CST)
Subject: [Edu-sig] Teaching students to use CVS
Message-ID: <Pine.GSO.4.21.0111142046190.26904-100000@isis.visi.com>

Hi everyone,

I'm a little more than 1/4 of the way through my Intro. to Comp. Prog. class
and we're starting to get into slightly more complicated assignments. (Well
maybe we're not quite there yet.)

Anyway, I'd like to have a way for my programming teams to collaborate on
their code. Has anyone tried teaching beginning comp. prog. students to use
CVS? It would be easy enough to drag out an old server and set it up for
this purpose.

Any hints or experiences that anyone would share?

-Tim

--
Tim Wilson      |   Visit Sibley online:   | Check out:
Henry Sibley HS |  http://www.isd197.org   | http://www.zope.com
W. St. Paul, MN |                          | http://slashdot.org
wilson@visi.com |  <dtml-var pithy_quote>  | http://linux.com



From jstraw@resample.com  Thu Nov 15 03:17:58 2001
From: jstraw@resample.com (Jason Straw)
Date: 14 Nov 2001 22:17:58 -0500
Subject: [Edu-sig] Teaching students to use CVS
In-Reply-To: <1005794151.22209.8.camel@jlaptop.towhee.com>
References: <Pine.GSO.4.21.0111142046190.26904-100000@isis.visi.com>
 <1005794151.22209.8.camel@jlaptop.towhee.com>
Message-ID: <1005794278.19763.11.camel@jlaptop.towhee.com>

They don't seem to have a problem with it... BUT i could never get it to
work remotely...  so it was never useful to them.. but i had them
grabbing programs anon. cvs from sourceforge (pyios.sf.net)

Jason

On Wed, 2001-11-14 at 21:49, Timothy Wilson wrote:
> Hi everyone,
> 
> I'm a little more than 1/4 of the way through my Intro. to Comp. Prog. class
> and we're starting to get into slightly more complicated assignments. (Well
> maybe we're not quite there yet.)
> 
> Anyway, I'd like to have a way for my programming teams to collaborate on
> their code. Has anyone tried teaching beginning comp. prog. students to use
> CVS? It would be easy enough to drag out an old server and set it up for
 this purpose.
> 
> Any hints or experiences that anyone would share?
> 
> -Tim
> 
> --
> Tim Wilson      |   Visit Sibley online:   | Check out:
> Henry Sibley HS |  http://www.isd197.org   | http://www.zope.com
> W. St. Paul, MN |                          | http://slashdot.org
> wilson@visi.com |  <dtml-var pithy_quote>  | http://linux.com
> 
> 
> _______________________________________________
> Edu-sig mailing list
> Edu-sig@python.org
> http://mail.python.org/mailman/listinfo/edu-sig 

-- 
Jason Straw
jstraw@resample.com  jstraw@ibiblio.org
Yorktown High School Linux Users' Group Meetings Coordinator /
yhslug.tux.org
Upcoming Meetings! October 5th: LTSP


From dustin@cs.uchicago.edu  Thu Nov 15 03:21:02 2001
From: dustin@cs.uchicago.edu (Dustin Mitchell)
Date: Wed, 14 Nov 2001 21:21:02 -0600 (CST)
Subject: [Edu-sig] Teaching students to use CVS
In-Reply-To: <Pine.GSO.4.21.0111142046190.26904-100000@isis.visi.com>
Message-ID: <Pine.LNX.4.21.0111142117040.6334-100000@broker.cs.uchicago.edu>

On Wed, 14 Nov 2001, Timothy Wilson wrote:

> Hi everyone,
> 
> I'm a little more than 1/4 of the way through my Intro. to Comp. Prog. class
> and we're starting to get into slightly more complicated assignments. (Well
> maybe we're not quite there yet.)
> 
> Anyway, I'd like to have a way for my programming teams to collaborate on
> their code. Has anyone tried teaching beginning comp. prog. students to use
> CVS? It would be easy enough to drag out an old server and set it up for
> this purpose.
> 
> Any hints or experiences that anyone would share?

Dave Beazley, author of Python Essential Reference and University of
Chicago Assistant Professor, uses CVS for most of his advanced-level
undergraduate courses.  It's worked out pretty well.  His course material
is available from his website, http://systems.cs.uchicago.edu/~beazley/,
including a quick overview of CVS.  

Basically he gives students the common syntaxes, and sends them to the
manpages for more.  But nearly all of the courses in that department are
"read the manpage or fail" classes.

If you're using Windoze, WinCVS may be an option -- it's not too
complicated to learn, and saves a lot on all that syntax you need for the
UNIX 'cvs' command.

Dustin

-- 

  Dustin Mitchell
  dustin@cs.uchicago.edu
  dustin@ywlcs.org



From dethe@burningtiger.com  Thu Nov 15 03:54:47 2001
From: dethe@burningtiger.com (Dethe Elza)
Date: Wed, 14 Nov 2001 19:54:47 -0800
Subject: [Edu-sig] Teaching students to use CVS
References: <Pine.GSO.4.21.0111142046190.26904-100000@isis.visi.com>
Message-ID: <3BF33C87.4020504@burningtiger.com>

Hi Tim,

I haven't tried teaching CVS to students, just co-workers, but when I 
discovered it my first thoughts were, "I wish someone had showed me this 
in school, it would have saved me a LOT of time and trouble."


Too many times of overwriting my working version in the heat of coding, 
or accidently deleting the work I'd struggled so long with because I
was too tired to know what I was doing.  I would often save everything
into a dated directory, but there was no context to it, so if I did have
to go back to an older version (assuming I'd saved the one I ended up
needing, which was rare), I had few clues to which one.

CVS has its faults, but it's orders of magnitude better than not using 
any revision system at all.  And after struggling with the 
idiosyncracies of SourceSafe I liked CVS even more %-)

So, no real tips, but I think it's a great idea.

--Dethe

-- 

Dethe Elza (delza@burningtiger.com)
Chief Mad Scientist
Burning Tiger Technologies (http://burningtiger.com)
Living Code Weblog (http://livingcode.ca)



From wilson@visi.com  Thu Nov 15 04:19:40 2001
From: wilson@visi.com (Timothy Wilson)
Date: Wed, 14 Nov 2001 22:19:40 -0600 (CST)
Subject: [Edu-sig] Teaching students to use CVS
In-Reply-To: <3BF33C87.4020504@burningtiger.com>
Message-ID: <Pine.GSO.4.21.0111142216340.714-100000@isis.visi.com>

On Wed, 14 Nov 2001, Dethe Elza wrote:

> I haven't tried teaching CVS to students, just co-workers, but when I 
> discovered it my first thoughts were, "I wish someone had showed me this 
> in school, it would have saved me a LOT of time and trouble."

Well I think CVS is probably overkill at this stage, but I thought I could
teach it to them now so when we get to more complicated projects (/me
crosses fingers <blatant Americanism probably...sorry>) they would be
comfortable with the idea.

I was reminding them today how I hoped that they would learn good
development practices and not just Python syntax. I think getting a handle
on CVS would qualify. :-)

-Tim

--
Tim Wilson      |   Visit Sibley online:   | Check out:
Henry Sibley HS |  http://www.isd197.org   | http://www.zope.com
W. St. Paul, MN |                          | http://slashdot.org
wilson@visi.com |  <dtml-var pithy_quote>  | http://linux.com



From Jason Cunliffe" <jasonic@nomadics.org  Thu Nov 15 23:04:20 2001
From: Jason Cunliffe" <jasonic@nomadics.org (Jason Cunliffe)
Date: Thu, 15 Nov 2001 18:04:20 -0500
Subject: [Edu-sig] Levitated Tile
Message-ID: <000801c16e29$dc5a3b60$0301060a@vaio>

This is a multi-part message in MIME format.

------=_NextPart_000_0005_01C16DFF.F2D4B980
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit

http://www.levitated.net/

..lovely openSource Flash5 generative art site, well designed interface


./Jason

------=_NextPart_000_0005_01C16DFF.F2D4B980
Content-Type: application/octet-stream;
	name="Levitated Tile.url"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
	filename="Levitated Tile.url"

[DEFAULT]
BASEURL=http://www.levitated.net/

[InternetShortcut]
URL=http://www.levitated.net/
Modified=6080A047296EC10120

------=_NextPart_000_0005_01C16DFF.F2D4B980--



From kimtitu@yahoo.com  Fri Nov 16 00:51:16 2001
From: kimtitu@yahoo.com (Titu Kim)
Date: Thu, 15 Nov 2001 16:51:16 -0800 (PST)
Subject: [Edu-sig] print to apache log from cgi script
Message-ID: <20011116005116.41958.qmail@web14702.mail.yahoo.com>

Hi,
   How can i output some message apache log files so i
can see the progress in cgi script? If i use regular
print, cgi prints the content to client browser. 

Thanks for any suggestion.

Regards,

Kim Titu

__________________________________________________
Do You Yahoo!?
Find the one for you at Yahoo! Personals
http://personals.yahoo.com


From schoen@loyalty.org  Fri Nov 16 01:05:48 2001
From: schoen@loyalty.org (Seth David Schoen)
Date: Thu, 15 Nov 2001 17:05:48 -0800
Subject: [Edu-sig] print to apache log from cgi script
In-Reply-To: <20011116005116.41958.qmail@web14702.mail.yahoo.com>
References: <20011116005116.41958.qmail@web14702.mail.yahoo.com>
Message-ID: <20011115170548.W15060@zork.net>

Titu Kim writes:

> Hi,
>    How can i output some message apache log files so i
> can see the progress in cgi script? If i use regular
> print, cgi prints the content to client browser. 
> 
> Thanks for any suggestion.

With many Unix web servers like Apache, writing data to standard error
instead of standard output results in its being logged instead of
transmitted to the client.

You can write things to standard error by doing something like

import sys
#
# ...
#
sys.stderr.write("hello there from my CGI script.\n")

These errors are written _directly_ into the Apache error log for the
appropriate virtual host, which means they will be intermingled with
things like HTTP errors.  That might not be what you want; it could be
better to open your own log file from within your CGI script, using
the "open" file, and write the data directly into your private log
file instead.

Questions about things like this might be more appropriate on some
other list, although I'm not sure which one.

-- 
Seth David Schoen <schoen@loyalty.org> | Its really terrible when FBI arrested
Temp.  http://www.loyalty.org/~schoen/ | hacker, who visited USA with peacefull
down:  http://www.loyalty.org/   (CAF) | mission -- to share his knowledge with
     http://www.freesklyarov.org/      | american nation.  (Ilya V. Vasilyev)


From kimtitu@yahoo.com  Fri Nov 16 01:22:45 2001
From: kimtitu@yahoo.com (Titu Kim)
Date: Thu, 15 Nov 2001 17:22:45 -0800 (PST)
Subject: [Edu-sig] print to apache log from cgi script
In-Reply-To: <20011115170548.W15060@zork.net>
Message-ID: <20011116012245.43683.qmail@web14703.mail.yahoo.com>

Thanks Schoen,
     I am trying to find a mailing list such as web
programming related. If anybody knows one, please do
not hesitate to tell me. 

Kim TItu
--- Seth David Schoen <schoen@loyalty.org> wrote:
> Titu Kim writes:
> 
> > Hi,
> >    How can i output some message apache log files
> so i
> > can see the progress in cgi script? If i use
> regular
> > print, cgi prints the content to client browser. 
> > 
> > Thanks for any suggestion.
> 
> With many Unix web servers like Apache, writing data
> to standard error
> instead of standard output results in its being
> logged instead of
> transmitted to the client.
> 
> You can write things to standard error by doing
> something like
> 
> import sys
> #
> # ...
> #
> sys.stderr.write("hello there from my CGI
> script.\n")
> 
> These errors are written _directly_ into the Apache
> error log for the
> appropriate virtual host, which means they will be
> intermingled with
> things like HTTP errors.  That might not be what you
> want; it could be
> better to open your own log file from within your
> CGI script, using
> the "open" file, and write the data directly into
> your private log
> file instead.
> 
> Questions about things like this might be more
> appropriate on some
> other list, although I'm not sure which one.
> 
> -- 
> Seth David Schoen <schoen@loyalty.org> | Its really
> terrible when FBI arrested
> Temp.  http://www.loyalty.org/~schoen/ | hacker, who
> visited USA with peacefull
> down:  http://www.loyalty.org/   (CAF) | mission --
> to share his knowledge with
>      http://www.freesklyarov.org/      | american
> nation.  (Ilya V. Vasilyev)
> 
> _______________________________________________
> Edu-sig mailing list
> Edu-sig@python.org
> http://mail.python.org/mailman/listinfo/edu-sig


__________________________________________________
Do You Yahoo!?
Find the one for you at Yahoo! Personals
http://personals.yahoo.com


From urnerk@qwest.net  Fri Nov 16 01:34:16 2001
From: urnerk@qwest.net (Kirby Urner)
Date: Thu, 15 Nov 2001 17:34:16 -0800
Subject: [Edu-sig] Re: Levitated Tile
In-Reply-To: <000801c16e29$dc5a3b60$0301060a@vaio>
Message-ID: <4.2.0.58.20011115172935.00c965e0@pop3.norton.antivirus>

At 06:04 PM 11/15/2001 -0500, Jason Cunliffe wrote:
>http://www.levitated.net/
>
>..lovely openSource Flash5 generative art site, well designed interface
>
>
>./Jason

Yes, this is excellent.  People with slower connections don't
like "swoopy" sites, but this shows how "swoopy" is NOT synonymous
with frivolous graphics, as here we're animating interesting
math-related ideas dynamically, with the powerful Flash 5
package.

Inspired by the Lorentz Attractor demo, I adapted the code
(with source cited/credited) to work with my pre-existing
coords.py and povray.py modules (freely downloadable and
used extensively at my math-through-programming teaching
site).

Here's the URL, with the resulting graphic up top (nothing
stunning):  http://www.inetarena.com/~pdx4d/ocn/lorentz.html

Gratifying to get something visual with so little code, as
with the fractal obtained earlier (linked in the 'For Further
Reading' section at bottom).

Thanks again, Jason -- you're good at mining the web, a fine
art in itself.

Kirby
Curriculum writer
Oregon Curriculum Network
& Oregon-Tips Python Curriculum




From djrassoc01@mindspring.com  Fri Nov 16 06:02:30 2001
From: djrassoc01@mindspring.com (Dr. David J. Ritchie, Sr.)
Date: Fri, 16 Nov 2001 00:02:30 -0600
Subject: [Edu-sig] Teaching Python to Middle School students...
References: <4.2.0.58.20011115172935.00c965e0@pop3.norton.antivirus>
Message-ID: <3BF4ABF5.A76783E6@mindspring.com>

[I have posted this information to comp.lang.python
and also to the analogous Perl newsgroup.  Sorry for
the repetition if you follow both groups but I was told
that the information should also go to this list.]

By the way, I have just started teaching Python to
students in a middle school computer club.  It's
going very well.

Having done a similar thing for Perl over the
past several years, I decided to try to do it for
Python.

I have put my perl handouts for the middle
school kids up on my web site:

http://home.mindspring.com/~djrassoc01/

After I have had a chance to classroom test and
refine my Python handouts, it is likely that they
will show up there as well.

--
Dr. David J. Ritchie, Sr.
djrassoc01@mindspring.com
http://home.mindspring.com/~djrassoc01/




From recip@a1-online-marketing-advertising.com  Mon Nov 26 00:23:17 2001
From: recip@a1-online-marketing-advertising.com (Gloria)
Date: Sun, 25 Nov 2001 19:23:17 -0500
Subject: [Edu-sig] Reciprocal Links
Message-ID: <200111251920.23w9r9A@192.168.0.2>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 5.50.4134.100" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2><FONT face="Times New Roman" size=3>I have reviewed 
your site and feel that it is of an excellent quality compared to many on the 
net.<BR><BR>We are looking for sites with which we can trade reciprocal links. 
Our site is called </FONT><A 
href="http://www.a1-online-marketing-advertising.com/"><FONT 
face="Times New Roman" size=3>A1 Online Marketing Advertising </FONT></A><FONT 
face="Times New Roman" size=3>and deals with <STRONG>marketing, advertising and 
web design.</STRONG> <BR><BR>It is a perfect complement to your site as it will assist your visitors
in marketing their companies. By linking
to us, you would provide your visitors a way to find a site they would likely 
find interesting, thus enhancing their experience at "your" site.<BR><BR>Our 
search engine, which will contain your link, operates on a 6:5 ratio. 
<STRONG>For every 5 unique click-throughs we receive from you, we pass 6 
back.</STRONG> This ensures that you always have a constant, fresh source of 
traffic.<BR><BR>Further, many search engines such as Google, Inktomi and Altavista 
include reciprocal linking as part of their algorithm. By exchanging links, you 
will be able to get listed higher in their search results.<BR><BR>Please go to 
<A href="http://www.a1-online-marketing-advertising.com/site-resources/">our 
search engine</A> to add your site and find details on how to link to 
us.<BR><BR>Thank you,<BR><BR>Gloria 
Hammond</FONT><BR></FONT></DIV></BODY></HTML>



From urnerk@qwest.net  Mon Nov 26 07:10:47 2001
From: urnerk@qwest.net (Kirby Urner)
Date: Sun, 25 Nov 2001 23:10:47 -0800
Subject: [Edu-sig] <FUN>more math with Python</FUN>
In-Reply-To: <4.2.0.58.20010930092216.00c31450@pop3.norton.antivirus>
References: <08ae01c149b2$0e344f00$cc090740@megapathdsl.net>
 <1001789273.2414.6.camel@robeson>
 <004b01c14954$66c8ca00$c3090740@jasonic>
Message-ID: <4.2.0.58.20011125225854.00c1a220@pop3.norton.antivirus>

Here's somethin' I wrote to compute e.  Uses 2.2's ability
to go with long integers on the fly, no explicit conversion
needed:

def gete(d):
     "Return the value of e with d digits"
     i = n = 1
     # approx number of terms needed
     terms = int(math.ceil(d * 4/math.log10(d)))
     e = val = 10**terms
     while i < terms:
        n *= i
        e += val/n
        i += 1
     val = str(e)
     return val[0]+"."+val[1:d]

Usage:

   >>> numb.gete(600)
   '2.718281828459045235360287471352662497757247093699959574966967627724
   076630353547594571382178525166427427466391932003059921817413596629043
   572900334295260595630738132328627943490763233829880753195251019011573
   834187930702154089149934884167509244761460668082264800168477411853742
   345442437107539077744992069551702761838606261331384583000752044933826
   560297606737113200709328709127443747047230696977209310141692836819025
   515108657463772111252389784425056953696770785449969967946864454905987
   931636889230098793127736178215424999229576351482208269895193668033182
   52886939849646510582093923982948879332036250944311'

I checked it against a web page going for thousands more digits.  So
far so good.  :-D

The approximation re terms needed, given request for d digits, could
probably use some fine tuning no doubt.

The approach uses the fact that e = 1/0! + 1/1! + 1/2! + 1/3!...
but with every term multiplied by 100000000000000000000000000000000...
or whatever so that computations all happen in positive long integer
world.

The final step is simply to take the digits in string form, and stick
in a decimal point after the 2.

Kirby



From bembry@bembry.org  Thu Nov 29 17:30:13 2001
From: bembry@bembry.org (Bryce Embry)
Date: Thu, 29 Nov 2001 11:30:13 -0600
Subject: [Edu-sig] Student Assignment Styles
Message-ID: <5.1.0.14.0.20011129111614.00aba460@bembry.org>

Howdy,
I'm in my first year of teaching computer programming in Python and am 
developing my material based on the How To Think Like A Computer Scientists 
book at www.ibiblio.org/obp.  I have to confess that I fell into teaching 
computer programming without any formal training, and I'm learning a lot of 
the material as we go along (I'm a few steps ahead of the students, but not 
far).

Looking through some of the edu_sig posts, and Timothy Wilson's page at 
http://www.isd197.org/sibley/cs/icp/, I'm seeing that assigning students a 
large project seems to be more popular than assigning a number of smaller, 
more pedantic problems. What is the rationale behind the larger projects as 
opposed to smaller projects?  What are the benefits and drawbacks of asking 
students to spend a week on one large project instead of that same week on 
three or four smaller tasks, then giving a large task once a month or 
so?  I've been using what I consider to be smaller projects (my stuff is at 
http://www.bembry.org/tech/python/index.shtml ) and am wondering if fewer, 
larger projects would be better for my kids.


-----------------------------------------------------------------------------------------
Bryce Embry
--- Geek of All Trades, Master of None
--- Margolin Hebrew Academy
--- 390 South White Station
--- Memphis, TN 38117
--- (901) 682-2409



From wilson@visi.com  Thu Nov 29 18:06:58 2001
From: wilson@visi.com (Timothy Wilson)
Date: Thu, 29 Nov 2001 12:06:58 -0600 (CST)
Subject: [Edu-sig] Student Assignment Styles
In-Reply-To: <5.1.0.14.0.20011129111614.00aba460@bembry.org>
Message-ID: <Pine.GSO.4.21.0111291202320.14068-100000@isis.visi.com>

On Thu, 29 Nov 2001, Bryce Embry wrote:

> Looking through some of the edu_sig posts, and Timothy Wilson's page at 
> http://www.isd197.org/sibley/cs/icp/, I'm seeing that assigning students a 
> large project seems to be more popular than assigning a number of smaller, 
> more pedantic problems.

I did many more small assignments at the beginning of the year--little
functions for programs that could be completed in twenty minutes or so. Now
that my students have been exposed to most of the Python syntax, I have them
working on larger assignments that are really just a bunch of little ones
glued together. Plus, the larger projects tend to be more interesting for
the students.

> I've been using what I consider to be smaller projects (my stuff is at 
> http://www.bembry.org/tech/python/index.shtml ) and am wondering if fewer, 
> larger projects would be better for my kids.

Thanks for the link. I'm always interested to see what other teachers are
doing.

-Tim

--
Tim Wilson      |   Visit Sibley online:   | Check out:
Henry Sibley HS |  http://www.isd197.org   | http://www.zope.com
W. St. Paul, MN |                          | http://slashdot.org
wilson@visi.com |  <dtml-var pithy_quote>  | http://linux.com



From Nora Wirtschafter <nww0002@mail.widener.edu>  Thu Nov 29 18:22:24 2001
From: Nora Wirtschafter <nww0002@mail.widener.edu> (Nora Wirtschafter)
Date: Thu, 29 Nov 2001 13:22:24 -0500 (EST)
Subject: [Edu-sig] Who is teaching Python??
Message-ID: <4420476.1007058144616.JavaMail.sainad@sage.edu>

------=_Part_9598_3991677.1007058144615
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

Dear Colleagues,

I am teaching Python at Widener University, Chester, PA, in CSCI 131, an elective science course for non-computer science majors. 

I am interested in knowing what other colleges, two- or four-year, are using Python as a teaching language.  Is Python offered at different levels in the curriculum? Computer Science majors at Widener use C as their beginning language; what language do your CS majors use as a start?  I am also interested in what texts you find appropriate (I have developed my own materials.)

Thank you for any responses.

Nora W. Wirtschafter, Instructor
Widener University
nww0002@mail.widener.edu

------=_Part_9598_3991677.1007058144615--



From jhrsn@pitt.edu  Thu Nov 29 18:46:13 2001
From: jhrsn@pitt.edu (Jim Harrison)
Date: Thu, 29 Nov 2001 13:46:13 -0500
Subject: [Edu-sig] Who is teaching Python??
In-Reply-To: <4420476.1007058144616.JavaMail.sainad@sage.edu>
Message-ID: <B82BECA4.AFDF%jhrsn@pitt.edu>

on 11/29/01 1:22 PM, Nora Wirtschafter at nww0002@mail.widener.edu wrote:

> I am interested in knowing what other colleges, two- or four-year, are using
> Python as a teaching language.

Our graduate course in introductory programming for Medical Informatics uses
Python. Information is available at:

http://jhh.cbmi.upmc.edu/pop/

Jim Harrison
________________________________________________________________________
James H. Harrison, Jr., MD, PhD  <mailto:jhrsn@pitt.edu>
Associate Director of Pathology Informatics, Department of Pathology
CLSI 5807-MT, 200 Lothrop Street
Pittsburgh, PA 15213-2582
voice: 412-647-5529 | fax: 412-647-5934

Faculty Member in Residence, Center for Biomedical Informatics
University of Pittsburgh
Suite 8084 Forbes Tower
Pittsburgh, PA 15213-2582
voice: 412-647-7113 | fax: 412-647-7190

"If you want sense, you'll have to make it yourself!!"-Norton Juster
________________________________________________________________________



From jeff@elkner.net  Thu Nov 29 18:59:56 2001
From: jeff@elkner.net (Jeffrey Elkner)
Date: 29 Nov 2001 13:59:56 -0500
Subject: [Edu-sig] Student Assignment Styles
In-Reply-To: <5.1.0.14.0.20011129111614.00aba460@bembry.org>
References: <5.1.0.14.0.20011129111614.00aba460@bembry.org>
Message-ID: <1007060396.12501.4.camel@mdeicaza>

Hi Bryce!

What I do first is assign small exercises from each chapter, and then
assign a big project.  I am using Tim's projects this year, and that has
been a *BIG* help.  (this collaboration thing is really working! ;-)

Not all of the chapters in the text book have enough exercises, which is
something I hope will be able to remedy in the next few weeks.  There
are two very good reasons for doing bigger projects:

1.  The ability to write meaningful programs should be a primary
teaching goal.  Academic programs have often come under criticism by
industry for not preparing students for "real world" programming.  There
is a natural tendancy in academia to focus on small examples that make
the concept transparent without confusing learners with extraneous
details.  The problem is students come away with no understanding of the
software development process itself.  Their learning doesn't scale up to
bigger problems.  This is also the motivation for the case study now
used in the Advanced Placeement program.

2. Big projects are Cool!  My experience is that students like them
because they solve more interesting problems.  Tim is doing a great job
of picking projects that my students enjoy doing (thanks again, Tim!)

jeff elkner
yorktown high school
arlington, va


On Thu, 2001-11-29 at 12:30, Bryce Embry wrote:
> Howdy,
> I'm in my first year of teaching computer programming in Python and am 
> developing my material based on the How To Think Like A Computer Scientists 
> book at www.ibiblio.org/obp.  I have to confess that I fell into teaching 
> computer programming without any formal training, and I'm learning a lot of 
> the material as we go along (I'm a few steps ahead of the students, but not 
> far).
> 
> Looking through some of the edu_sig posts, and Timothy Wilson's page at 
> http://www.isd197.org/sibley/cs/icp/, I'm seeing that assigning students a 
> large project seems to be more popular than assigning a number of smaller, 
> more pedantic problems. What is the rationale behind the larger projects as 
> opposed to smaller projects?  What are the benefits and drawbacks of asking 
> students to spend a week on one large project instead of that same week on 
> three or four smaller tasks, then giving a large task once a month or 
> so?  I've been using what I consider to be smaller projects (my stuff is at 
> http://www.bembry.org/tech/python/index.shtml ) and am wondering if fewer, 
> larger projects would be better for my kids.
> 
> 
> -----------------------------------------------------------------------------------------
> Bryce Embry
> --- Geek of All Trades, Master of None
> --- Margolin Hebrew Academy
> --- 390 South White Station
> --- Memphis, TN 38117
> --- (901) 682-2409



From jeff@elkner.net  Thu Nov 29 19:12:24 2001
From: jeff@elkner.net (Jeffrey Elkner)
Date: 29 Nov 2001 14:12:24 -0500
Subject: [Edu-sig] Student Assignment Styles
In-Reply-To: <5.1.0.14.0.20011129111614.00aba460@bembry.org>
References: <5.1.0.14.0.20011129111614.00aba460@bembry.org>
Message-ID: <1007061144.12501.6.camel@mdeicaza>

Hello again, Bryce!

I just took a look at your site and it looks nice!  I would like to ask
two favors:

1. Can we list you on the list of schools page?

http://www.ibiblio.org/obp/pyBiblio/schools.php

If that is okay, please send a paragram describing your school/program
to Lex Berezhny:

lex@berezhny.net

2. Can I put your exercises/nots on the pyBiblio site as well?

My hope is that by leveraging the sharing and collaboration made
possible by free content and the web we can both enhance student
learning and reduce our work load at the same time.

I put more hours than I can remember into working on the text book (it
was fun), but I'm glad now that Tim is writing up interesting projects,
so I don't have to do that.

The more materials we can get on the site the easier it will be for
other teachers to use Python.

Thanks!

jeff elkner
yorktown high school
arlington, va


On Thu, 2001-11-29 at 12:30, Bryce Embry wrote:
> (my stuff is at 
> http://www.bembry.org/tech/python/index.shtml )
>
> Bryce Embry
> --- Geek of All Trades, Master of None
> --- Margolin Hebrew Academy
> --- 390 South White Station
> --- Memphis, TN 38117
> --- (901) 682-2409



From urnerk@qwest.net  Thu Nov 29 19:13:45 2001
From: urnerk@qwest.net (Kirby Urner)
Date: Thu, 29 Nov 2001 11:13:45 -0800
Subject: [Edu-sig] Student Assignment Styles
In-Reply-To: <1007060396.12501.4.camel@mdeicaza>
References: <5.1.0.14.0.20011129111614.00aba460@bembry.org>
 <5.1.0.14.0.20011129111614.00aba460@bembry.org>
Message-ID: <4.2.0.58.20011129111256.019f7df0@pop3.norton.antivirus>

>
>2. Big projects are Cool!  My experience is that students like them
>because they solve more interesting problems.  Tim is doing a great job
>of picking projects that my students enjoy doing (thanks again, Tim!)

Yeah, I liked doing the weather one.

Kirby



From dyoo@hkn.eecs.berkeley.edu  Fri Nov 30 01:23:26 2001
From: dyoo@hkn.eecs.berkeley.edu (Danny Yoo)
Date: Thu, 29 Nov 2001 17:23:26 -0800 (PST)
Subject: [Edu-sig] Who is teaching Python??
In-Reply-To: <4420476.1007058144616.JavaMail.sainad@sage.edu>
Message-ID: <Pine.LNX.4.21.0111291720010.13738-100000@hkn.eecs.berkeley.edu>

On Thu, 29 Nov 2001, Nora Wirtschafter wrote:

> I am interested in knowing what other colleges, two- or four-year, are
> using Python as a teaching language.  Is Python offered at different
> levels in the curriculum? Computer Science majors at Widener use C as
> their beginning language; what language do your CS majors use as a
> start?  I am also interested in what texts you find appropriate (I
> have developed my own materials.)


Hi Nora,

UC Berkeley uses the Scheme language in its introductory course "CS61A":

    http://inst.eecs.berkeley.edu/~cs61a/

The course uses "The Structure and Interpretation of Computer Programs" as
the main textbook:

    http://mitpress.mit.edu/sicp/


Hope this helps!



From urnerk@qwest.net  Fri Nov 30 08:42:17 2001
From: urnerk@qwest.net (Kirby Urner)
Date: Fri, 30 Nov 2001 00:42:17 -0800
Subject: [Edu-sig] More fun with Euler's Number
In-Reply-To: <4.2.0.58.20011125225854.00c1a220@pop3.norton.antivirus>
References: <4.2.0.58.20010930092216.00c31450@pop3.norton.antivirus>
 <08ae01c149b2$0e344f00$cc090740@megapathdsl.net>
 <1001789273.2414.6.camel@robeson>
 <004b01c14954$66c8ca00$c3090740@jasonic>
Message-ID: <4.2.0.58.20011129235051.00948ef0@pop3.norton.antivirus>

>
>The approximation re terms needed, given request for d digits, could
>probably use some fine tuning no doubt.

Here's another stab at generating e to more-than-we-usually-get
decimals.

There's this algebraic transformation, which I haven't quite
figured out yet, that lets you rewrite 1 + 1/1! + 1/2! + 1/3!
+ 1/4! + 1/5! as 1+(1+(1+(1+(1+1/5)/4)/3)/2)/1.  This translates
into a very simple algorithm for e (see below), used by
Jean-Michel Ferrard in a program for the TI (calculator).
He manages to get 600 significant digits out of the thing
(a TI-92 or 89).

But this algorithm requires knowing in advance how many terms
you need in order to produce n significant digits.  Jean-Michel
knows 294 is the magic number for 600 digits, but the best
approximation I was able to find, for the number of terms,
was here: http://numbers.computation.free.fr/Constants/E/e.html
where is written:  "To have d decimal digits of e, the first
K ~ d log(10)/log(d) terms of the series are sufficient"
(Section 7).

But that's approximate, and it doesn't work for a lot of the
values of d that I try.  My earlier approach was to boost it
higher -- but how much higher would I need to go?  I went
too far.

If we're really not sure in advance how many terms to
compute, how do we stop from running through too many?
I thought a good way to apply the brakes would be to
check the least significant bits of the long integer
being completed, and to say "if these bits don't change
through 10 iterations, then we're done".  I also go
to a few digits beyond what the user requests, for
good measure, but only display the number of decimals
(= terms) actually asked for.

Here's a program implementing this strategy, along with a
different form of the algorithm derived in Section 4 of the
above web resource.

def gete(terms):
     e = 10 ** (terms + 5)
     sig = u = n = 1
     cnt = 0
     while cnt < 10:
        e = (e * (u+1))//u
        u = (n+1)*(u+1)
        n += 1
        leastsig = e & 1111

        if leastsig == sig:  cnt += 1
        else:
           sig = leastsig
           cnt = 0

     se = str(e)
     return se[0]+"."+se[1:terms+1]

I asked for the first 6000 digits of e, and was able to compare them
with an online resource to ascertain my result indeed ended with the
right digits:  ...6110250517100   It goes through about 2090
iterations to reach the terminal condition, whereas the log formula
would suggest 1588.

Takes about 50 seconds to complete on my 1.2 Ghz AMD w/ 640 MB RAM
(ymmv).

However, now that I know I should use about 2090 iterations, if
I use the algorithm in Jean-Michel Ferrard's paper (it was
emailed to me -- not on the web AFAIK), then I get 6000 digits
in a blindingly short time, under 1 second!  Sheesh, that's a
*huge* difference.  Here's that algorithm:

   def gete2():
       "Return the value of e with 6000 digits"
       u = x = 10**6000
       for k in range(2090,0,-1):
           u = x + u//k
       return str(u)

Clearly, knowing the number of terms in advance, and using
the above (which implements the algebraic transformation I
mention up top), is the superior method, by a long shot.
I need to get a better grip on this "knowing how many terms
in advance" issue.

Of course none of these methods are what the professionals
are using to compute e to millions or billions of digits.
That's a whole other ballgame, using 'binary splitting' and
the like (involves Fourier Transforms -- 'Who is Fourier?').
Still, this game is fun enough, if not ground-breaking
(and it's educational).

Kirby



From rkr_ii@yahoo.com  Fri Nov 30 20:21:46 2001
From: rkr_ii@yahoo.com (Robert Rickenbrode II)
Date: Fri, 30 Nov 2001 15:21:46 -0500
Subject: [Edu-sig] RealTimeBattle and Python
Message-ID: <5.0.2.1.0.20011130151951.00a875a0@pop.mail.yahoo.com>

Anyone have any experience using RealTimeBattle 
(http://realtimebattle.sourceforge.net/) with Python?
Just a consideration...

Robert K. Rickenbrode II
rkr_ii@yahoo.com