Flatten python collection

flatten_list.py

# following code uses recursion, so it may run out of stack memeory for large collections

def flatten(container):
    """generate a flatten sequence from the input list"""   
    for i in container:
        if isinstance(i, (list, tuple)):
            for j in flatten(i):
                yield j
        else:
            yield i

            

print list(flatten([])) == []
print list(flatten([[1 ,2, [3]], 4])) == [1, 2, 3, 4]
print list(flatten([1, 2, [3, 4, [5], [34]], [6, [[[7, 89]]]]])) == [1, 2, 3, 4, 5, 34, 6, 7, 89]