Python find the minimum length of string to differentiate dictionary items

[Gribouillis]

Here is a solution with module itertools

import itertools as it

def index_two(a, b):
    '''return the first index where the two words differ
    If they don't differ, return the length of the smallest'''
    return next(
        it.dropwhile(lambda t: t[0]==t[1], zip(a, b, it.count(0))),
        (None, None, min(len(a), len(b))))[2]

def index_many(words):
    '''return the first index where all the words differ
    identical words are considered to differ on the next character'''
    seq = sorted(words)
    if not seq: return 0
    a, b = it.tee(seq)
    next(b, None)
    return max((index_two(*t) for t in zip(a, b)), default=0)


def shorten_names(dic):
    n = index_many(dic.values())
    return {k: v[:1+n] for k, v in dic.items()}
    
dTeamNames = {'A': 'Man City', 'B': 'Man United', 'C': 'West Brom', 'D': 'West Ham'}
dShortNames = shorten_names(dTeamNames)
print(dShortNames)