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

[Luke Paireepinart]

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()
>
>
> --
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> http://linuxcrazy.com
>
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