Flatten (an irregular) list of lists in Python

flatten.py

# http://stackoverflow.com/questions/2158395/flatten-an-irregular-list-of-lists-in-python

def flatten(nested_list):
    for i in nested_list:
        if isinstance(i, collections.Iterable) and not isinstance(i, (str, bytes)):
            yield from flatten(i)
        else:
            yield i