return statement in functions

[Peter Otten]

hokiegal99 wrote:

> I was told earlier (w/o explanation) that functions should return
> something. I was under the impression that it was OK with Python to
> leave the return statement off. Could someone enlighten me on why or
> why not to use a return statement when defining functions? Below is
> the bit of code I was told should return something:
> 
> def fs_object_count(path):
>    file_count = 0
>    dir_count = 0
>    for root, dirs, files in os.walk(path):
>       file_count += len(files)
>       dir_count += len(dirs)
>    print "Number of Files Examined: ", file_count
>    print "Number of Folders Examined: ", dir_count
>    print "Total Number of FS Objects:", file_count + dir_count

I think I was the guy who told that. I did not mean that you should always
add an explicit return statement, you just posted a slightly different
function

[hokiegal99 in earlier post]

> def fs_object_count(path):
>     file_count = 0
>     dir_count = 0
>     for root, dirs, files in os.walk(path):
>        for fname in files:
>           file_count += len(fname)
>        for dname in dirs:
>           dir_count += len(dname)
> fs_object_count()


which attempted to calculate file and dir count but did neither return these
values nor print them. Thus the file_count and dir_count were lost and the
function useless.
 
As to the advantage of returning the result instead of printing it, Francis
Avila has already covered that.

Peter