Flatten irregular array

flatten.py

def flatten(source):
    """
    Flattens an irregular array into a single dimension.

    :param list source: The array to flatten
    :rtype: list
    :returns: The flattened array
    """

    assert isinstance(source, (list, tuple)), 'Only lists and tuples are supported'

    dest = list()

    for el in source:
        if isinstance(el, (list, tuple)):
            dest += flatten(el)
        else:
            dest.append(el)

    return dest