Check if a list exists in given list of lists

[deanhystad]

This is why your original program did not work:

import collection
x = collections.Counter(['a', 'b'])
y = collections.Counter(['b', 'a'])
print(x)
print(y)
print(x==y)

Output:
Counter({'a': 1, 'b': 1})
Counter({'b': 1, 'a': 1})
True

Counter does not care about order of entries in the source collection.

This is what your function does with all the extra stuff removed:

numbers = [('a','a'), ('c','a')]

def find_edge(nodes, x, y):
    for node in nodes:
        if x == node[0] and y == node[1]:
            return True
    return False

print(find_edge(numbers, 'a', 'c'))
print(find_edge(numbers, 'c', 'a'))

Output:
False
True