def xfrange(start, stop=None, step=1):
	"""
	Iterate through an arithmetic progression.

	:param start: Starting number.
	:type start: float, int, long
	:param stop: Stopping number.
	:type stop: float, int, long
	:param step: Stepping size.
	:type step: float, int, long
	"""
	if stop is None:
		stop = start
		start = 0.0
	start = float(start)
	while start < stop:
		yield start
		start += step
Iterate through an arithmetic progression.

	:param start: Starting number.
	:type start: float, int, long
	:param stop: Stopping number.
	:type stop: float, int, long
	:param step: Stepping size.
	:type step: float, int, long