Determine prefix from a set of (similar) strings

Question

I have a set of strings, e.g.

my_prefix_what_ever
my_prefix_what_so_ever
my_prefix_doesnt_matter

I simply want to find the longest common p

Answer 1

I had a slight variation of the problem and google sends me here, so I think it will be useful to document:

I have a list like:

• my_prefix_what_ever
• my_prefix_what_so_ever
• my_prefix_doesnt_matter
• some_noise
• some_other_noise

So I would expect my_prefix to be returned. That can be done with:

from collections import Counter

def get_longest_common_prefix(values, min_length):
    substrings = [value[0: i-1] for value in values for i in range(min_length, len(value))]
    counter = Counter(substrings)
    # remove count of 1
    counter -= Counter(set(substrings))
    return max(counter, key=len)