[Tutor] if: else: can not get else to work

[Luke Paireepinart]

Oops, you should probably have a "return True" at the end of the function so
the return value is meaningful.
On Tue, Jul 7, 2009 at 9:29 PM, Luke Paireepinart <rabidpoobear at gmail.com>wrote:

> I typically abuse the fact that "return" will get you out of a function to
> make my code indented less.perhaps others would frown upon this but it
> makes sense to me.
> With various other changes, I'd make your function like so:
> from os import path, listdir, remove
>
> def clean(folder):
>     if not path.exists(folder):
>         print "Folder does not exist!"
>         return False
>     files = listdir(folder)
>
>     if not len(files):
>         print "Folder is empty!"
>         return False
>
>     files.sort()
>     for f in files:
>         target = path.join(folder, f)
>         if not path.isfile(target):
>             print "skipping directory", f
>             continue
>         print "removing file", f
>         remove(target)
>
> clean("/var/log/motion")
>
> Also, about the address - yes please!  can you make it forward to my gmail?
>
>
> On Tue, Jul 7, 2009 at 9:05 PM, David <david at pythontoo.com> wrote:
>
>> Luke Paireepinart wrote:
>>
>>>
>>>
>>> On Tue, Jul 7, 2009 at 8:36 PM, David <david at pythontoo.com <mailto:
>>> david at pythontoo.com>> wrote:
>>>
>>>    Hi Tutors,
>>>
>>> Hiya david.  Cool e-mail address :)
>>>
>>
>> Thanks, want luke at pythontoo.com I have a few to spare :)
>>
>>
>>>    But if there are no files in the directory it never gets to the else.
>>>
>>> Right, if there are no files in the directory, then fobj will contain 0
>>> items, so when the outer "for file in obj" loop iterates over it, there will
>>> be no values for "file" to take.
>>>
>>> One note - "file" is a builtin (probably deprecated in 3.0 but it's still
>>> a builtin in 2.4) so you might not want to use it as filenames.  Maybe use
>>> "fname"?  I think in later versions of Python file() is just aliased to
>>> open(), or at least it has fewer features, so probably it should be
>>> deprecated by now anyway.  Just a thought.
>>>
>>> Do you need help with adding this "no files" statement or would you like
>>> to solve it yourself?  I feel like your question was just to confirm that
>>> there was nothing wrong with your code, and there isn't, you just need to
>>> find the correct way to display this prompt.  hint: if the "for" loop isn't
>>> iterating over the items, you won't get to print this message, but you also
>>> know that the length of the fobj file must be 0 items, right?  Think of how
>>> you can use this to your advantage. :)
>>>
>>>
>>>
>> Ok, here is what I came up with;
>>
>> #!/usr/bin/python
>> import commands
>> import os
>> from sys import exit
>>
>> def clean_motion():
>>    folder = '/var/log/motion'
>>    if os.path.exists(folder):
>>        fobj = os.listdir(folder)
>>        if len(fobj) == 0:
>>            print 'No files to clean.'
>>        else:
>>            fobj.sort()
>>            for fname in fobj:
>>                pathname = os.path.join(folder, fname)
>>                if os.path.exists(pathname):
>>                    print 'removing... ', fname
>>                    os.remove(pathname)
>>
>> if __name__ == "__main__":
>>    if commands.getoutput( "whoami" ) != "root":
>>        exit("\tYou must be root! Try again please.")
>>    clean_motion()
>>
>>
>> --
>> Powered by Gentoo GNU/Linux
>> http://linuxcrazy.com
>>
>
>
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