count items in generator

[George Sakkis]

BartlebyScrivener wrote:

> Still new. I am trying to make a simple word count script.
>
> I found this in the great Python Cookbook, which allows me to process
> every word in a file. But how do I use it to count the items generated?
>
> def words_of_file(thefilepath, line_to_words=str.split):
>     the_file = open(thefilepath)
>     for line in the_file:
>         for word in line_to_words(line):
>                 yield word
>     the_file.close()
> for word in words_of_file(thefilepath):
>     dosomethingwith(word)
>
> The best I could come up with:
>
> def words_of_file(thefilepath, line_to_words=str.split):
>     the_file = open(thefilepath)
>     for line in the_file:
>         for word in line_to_words(line):
>                 yield word
>     the_file.close()
>     len(list(words_of_file(thefilepath)))
>
> But that seems clunky.

As clunky as it seems, I don't think you can beat it in terms of
brevity; if you care about memory efficiency though, here's what I use:

def length(iterable):
    try: return len(iterable)
    except:
        i = 0
        for x in iterable: i += 1
        return i

You can even shadow the builtin len() if you prefer:

import __builtin__

def len(iterable):
    try: return __builtin__.len(iterable)
    except:
        i = 0
        for x in iterable: i += 1
        return i


HTH,
George