Finding a tuple in large a very large list

Question

Suppose I have a list of tuples:

tuple_library = [('a', 'z', '1'), ('r', '3', 'b'), ('m', '1', 'l')]

What I want to do is to check if the following tuple is present on the tuple_library.

search_list = [('a','a','1'), ('m', '1', 'l')]


def search_the_tupple(t_lib, s_list):
    for item in t_lib:
        if item in s_list:
           return(item)

print(search_the_tupple(tuple_library, search_list))

this code works ok if the tuple_library and the search_list is small, but as those two item increases, the longer time needed in order for it to complete.

How do we approach this problem?

Answer 1

1. Convert tuple_library and search_list to a python set with set()
2. Return the intersection of the two sets, that is, all the elements that are in both tuple_library and search_list

tuple_library = [('a', 'z', '1'), ('r', '3', 'b'), ('m', '1', 'l')]
search_list = [('a','a','1'), ('m', '1', 'l')]


def search_the_tupple(t_lib, s_list):
    return set(t_lib).intersection(set(s_list))


print(search_the_tupple(tuple_library, search_list))

This is assuming that you want the order of the tuple to be preserved. (so that a ('m', '1', 'l') would appear but a ('m', 'l', '1') would not.

Fyi: it does not matter whether you do t_lib.intersection(s_list) or the other way around.