Practical range in Python

prange.py

# unlike range, prange works automatically with reverse ranges, floats, and 0 steps
# prange(0,-10) --> 0, -1, -2, -3, -4, -5, -6, -7, -8, -9
# prange(1,2,.1) --> 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9
# prange(0,1,0) --> 0, 0, 0, ...
# prange(a,b,c) --> range(a,b,c) # when a,b,c are positive integers and a<b

# prange stands for practical range
def prange(start, stop=None, step=1):

    if stop is None:
        stop = start
        start = 0

    yield start

    step = abs(step)

    if stop < start:
        step = -step

    while (start - stop) * (start + step - stop) > 0:
        start += step
        yield start