Python `range` but with float starts, ends and steps

frange.py

def frange(start, end=None, step=None):
    assert (end is None) <= (step is None)
    if end is None:
        start, end, step = 0, start, 1
    elif step is None:
        step = 1
    assert step != 0
    sign = -1 if step < 0 else 1
    v = start
    while v * sign < end * sign:
        yield v
        v += step