Help please: How to assign an object name at runtime

[John Machin]

c0chong at gmail.com wrote:
> Good day:
> Probably the answer to my question is staring me in the face, but the
> solution escapes me.
> 
> The following is the input line of the file: SoftDict-.csv:
>   ca1017,GRPHScriptSet,ADD/REM,Adobe Acrobat 4.0=2005/06/14
> 
> I expected an instance of Machine() to be created with a name ca1017.

There is absolutely no basis at all for this expectation. How did you 
arrive at it?

> 
> Instead, an object is assigned to l[0] named:
>    <__main__.Machine instance at 0x01282558>

The object is assigned to l[0] exactly as you dictated, i.e. its name is 
l[0]. The former referent of l[0] i.e. the string whose value is 
"ca1017" is no longer in view and will be garbage-collected.

What are you really wanting to do?

BTW, don't use "l".

> 
> -----------------------------
> Here is my code:
> 
> class Machine:
>     def __init__(self):
>         self.software = []# Holds attributes of the instance

Do you mean like self.software ultimately =
['GRPHScriptSet', 'ADD/REM', 'Adobe Acrobat 4.0=2005/06/14'] ?

That's not quite what the man meant when he said 'object-oriented'!!

>     def add(self, sware):
>         self.software.append(sware)# Append attribute
>         return self.software
>     def show(self):
>         return self.software
>     def __call__(self):
>         return [ e for e in self.software]

Isn't that the same as "return self.software"?

So obj.show() and obj() return an attribute of obj? That's an 
"interesting" interface.

Lose the __call__ -- you don't need it.


>     def cnt(self):
>         return '%s' % (len(self.software))

Why not just return the length as an integer???

>     def installed(self, sware):
>         if sware in self.software:
>             return True
>         else:
>             return False

Try "return sware in self.software"

> 
> class FileList:
>     def __init__(self, filename):
>         self.file = open(filename, 'r')     # open and save file
>     def __getitem__(self, i):               # overload indexing
>         line = self.file.readline()
>         if line:
>             return line                     # return the next line
>         else:
>             raise IndexError                # end 'for' loops, 'in'
>     def __getattr__(self, name):
>         return getattr(self.file, name)     # other attrs
> 
> 
> if __name__ == '__main__':
> 
>     import sys, fileinput, os, string	# when run, not imported
> 
>     for line in FileList('SoftDict-.csv'): # Treat .csv as a text
>         if len(line)==1: break	# Quit processing; end of file
>         l=line.split(',')# Split the line into constituent parts
>         l[0]=Machine()	# Create a Machine() object named: ca1017
> -------------------------------------------
> 
> That's it.  I evidently have no idea what I am doing.

The whole FileList class is pointless. Step 1: replace """for line in 
FileList(filename):"""

with """for line in open(filename):"""

and lose the """if .... : break""" line.

Step 2: read up on the csv module, and lose the "split".

Step 3: you are unlikely to *ever* need the string and fileinput modules

Step 4: you import 4 modules you don't use. Why?

Oh and BTW Step 0: what are the requirements for this exercise, what do 
the fields in the file actually represent, what is that bloody = sign 
between 'Adobe Acrobat' and the date aaaarrrggghhhh words fail me [finally]


... exiting in pursuit of paracetamol,
John