flatten an array of arbitrarily nested arrays into a flat array (e.g. [[1,2,[3]],4] -> [1,2,3,4])

flatten.py

#!/usr/bin/env python3
"""
Small module to flatten iterables
"""

def flatten(obj):
    """Flatten any nested iterables.

    >>> flatten([[1,2,[3]],4])
    [1, 2, 3, 4]

    It works with any iterable

    >>> flatten([1,2,(3,4)])
    [1, 2, 3, 4]

    It works with any depth, including 0

    >>> flatten([[[[[[[[[[1]]]]]]]]]])
    [1]

    >>> flatten(1)
    [1]
    """
    result = []
    # We use python's duck-typing to detect if an object is iterable
    try:
        for elem in obj:
            result += flatten(elem)
    except TypeError:
        result = [obj]
    return result

if __name__ == '__main__':
    import doctest
    doctest.testmod()