[Tutor] if: else: can not get else to work
rabidpoobear at gmail.com
Wed Jul 8 04:31:01 CEST 2009
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
> for f in files:
> target = path.join(folder, f)
> if not path.isfile(target):
> print "skipping directory", f
> print "removing file", f
> 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;
>> 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.'
>> for fname in fobj:
>> pathname = os.path.join(folder, fname)
>> if os.path.exists(pathname):
>> print 'removing... ', fname
>> if __name__ == "__main__":
>> if commands.getoutput( "whoami" ) != "root":
>> exit("\tYou must be root! Try again please.")
>> Powered by Gentoo GNU/Linux
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