unpack.py

"""
ValueError: not enough values to unpack (expected 3, got 2)
ValueError: too many values to unpack (expected 3)
"""

def unpack(iterable, length):
    i = iter(iterable)

    ret = [x for x, _ in zip(i, range(length))]

    if len(ret) < length:
        raise ValueError("not enough values to unpack (expected {}, got {})".format(length, len(ret)))

    try:
        next(i)
    except StopIteration:
        return ret

    raise ValueError("too many values to unpack (expected {})".format(length))