Is this a bug or am I crazy?

[jimscafe]

I have a piece of code as follows :-

    files = getallfiles(path)
    filteredfiles = [x for x in files if not (x.lower().split('.')[-1] in no_ext)]
    print filteredfiles
    return filteredfiles
 

It may be clumsy code but the intention is to take the list of files from getallfiles()
and exclude those files with the extension in no_ext which is a list of file extensions I don't want. (no_ext = ['pyc', 'zip', 'ini'])

Here's the problem, the above code works fine, but if I remove the
print filteredfiles
command the files with the unwanted extensions are still there in filteredfiles
I even tried putting in
filteredfiles = filteredfiles[:]
but that didn't help.

It looks like the list comprehension is not working until I print out filteredfiles!

I must be doing something wrong....

(python 2.5)

[ghostdog74]

I have a piece of code as follows :-

files = getallfiles(path)
filteredfiles = [x for x in files if not (x.lower().split('.')[-1] in no_ext)]
print filteredfiles
return filteredfiles

It may be clumsy code but the intention is to take the list of files from getallfiles()
and exclude those files with the extension in no_ext which is a list of file extensions I don't want. (no_ext = ['pyc', 'zip', 'ini'])

Here's the problem, the above code works fine, but if I remove the
print filteredfiles
command the files with the unwanted extensions are still there in filteredfiles
I even tried putting in
filteredfiles = filteredfiles[:]
but that didn't help.

It looks like the list comprehension is not working until I print out filteredfiles!

I must be doing something wrong....

(python 2.5)

can you do this

...
    files = getallfiles(path)
    print files , type(files)
    filteredfiles = [x for x in files if not (x.lower().split('.')[-1] in no_ext)]
    print filteredfiles
    return filteredfiles
 

and show the results of the print statements here.thanks

[jimscafe]

Not sure if this is what you intended. This output shows filteredfiles to be correct (the .pyc files have been removed). It is when I omit the print filteredfiles command that the returned list is incorrect.

Here is the output :-

['c:/programing/source/python/pythonlib\\__init__.py',
'c:/programing/source/python/pythonlib\\datetime\\CalcTime.py',
'c:/programing/source/python/pythonlib\\datetime\\CalcTime.pyc', 'c:/programing/source/python/pythonlib\\datetime\\__init__.py', 'c:/programing/source/python/pythonlib\\files\\FileCopy.py',
'c:/programing/source/python/pythonlib\\files\\FileCopy.pyc',
'c:/programing/source/python/pythonlib\\files\\NewConfigParser.py', 'c:/programing/source/python/pythonlib\\files\\NewConfigParser.pyc', 'c:/programing/source/python/pythonlib\\files\\PollHotFolder.py', 'c:/programing/source/python/pythonlib\\files\\PollHotFolder.pyc',
'c:/programing/source/python/pythonlib\\files\\__init__.py',
'c:/programing/source/python/pythonlib\\files\\__init__.pyc',
'c:/programing/source/python/pythonlib\\messaging\\basicmsg.py', 'c:/programing/source/python/pythonlib\\messaging\\basicmsg.pyc', 'c:/programing/source/python/pythonlib\\messaging\\messageframe.py', 'c:/programing/source/python/pythonlib\\messaging\\messageframe.pyc',
'c:/programing/source/python/pythonlib\\messaging\\textfileprotocol.py',
'c:/programing/source/python/pythonlib\\messaging\\textfileprotocol.pyc',
'c:/programing/source/python/pythonlib\\messaging\\__init__.py',
'c:/programing/source/python/pythonlib\\messaging\\__init__.pyc']
<type 'list'>
['c:/programing/source/python/pythonlib\\__init__.py',
'c:/programing/source/python/pythonlib\\datetime\\CalcTime.py',
'c:/programing/source/python/pythonlib\\datetime\\__init__.py', 'c:/programing/source/python/pythonlib\\files\\FileCopy.py', 'c:/programing/source/python/pythonlib\\files\\NewConfigParser.py',
'c:/programing/source/python/pythonlib\\files\\PollHotFolder.py',
'c:/programing/source/python/pythonlib\\files\\__init__.py',
'c:/programing/source/python/pythonlib\\messaging\\basicmsg.py', 'c:/programing/source/python/pythonlib\\messaging\\messageframe.py', 'c:/programing/source/python/pythonlib\\messaging\\textfileprotocol.py', 'c:/programing/source/python/pythonlib\\messaging\\__init__.py']

[bartonc]

I have a piece of code as follows :-

    files = getallfiles(path)
    filteredfiles = [x for x in files if not (x.lower().split('.')[-1] in no_ext)]
    print filteredfiles
    return filteredfiles
 

It may be clumsy code but the intention is to take the list of files from getallfiles()
and exclude those files with the extension in no_ext which is a list of file extensions I don't want. (no_ext = ['pyc', 'zip', 'ini'])

Here's the problem, the above code works fine, but if I remove the
print filteredfiles
command the files with the unwanted extensions are still there in filteredfiles
I even tried putting in
filteredfiles = filteredfiles[:]
but that didn't help.

It looks like the list comprehension is not working until I print out filteredfiles!

I must be doing something wrong....

(python 2.5)

Hello (is it Jim?). If you provide the entire code (including getallfiles()) then we'll have a chance to run it on different versions of python and see if we can track this down for you. Please read "REPLY GUIDELINES" on the right hand side of the page (while composing your reply) to see what CODE tags look like. Thanks for joining.

[jimscafe]

Thanks guys, there's no fool like an old fool.

The problem was some debug print statements that made it look like the list had not been changed...but in fact it had been changed.

All is well now and no need to tell the python programmers to re-write python!!!!