A quick Python port of the Ruby Abbrev module

abbrev.py

#!/usr/bin/python

"""
Copyright (c) 2011 Wander Nauta http://wandernauta.nl

This is a based on the Abbrev module that ships with Ruby, by Akinori Mushi.
Thanks, Akinori!

This snippet is distributed in the hope that it will be useful, but WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND. Have fun. 
"""

def abbrev(*words):
    """
    Calculate the set of unique abbreviations for a given set of strings.
    Useful for calculating abbreviations for commands.
    """
    table = {}
    seen = {}
    
    for word in words:
        for count in range(1, len(word)):
            abbr = word[0:count]
            if abbr in seen:
                del table[abbr]
                del seen[abbr]
            else:
                table[abbr] = word                
                seen[abbr] = word
    
    for word in words:
        table[word] = word
    
    return table

if __name__ == "__main__":
    import pprint
    pprint.pprint(abbrev('install', 'update', 'upgrade', 'home', 'help'))