343 	def round2(number, ndigits=None):  argument
357 		if ndigits is None:
358 			ndigits = 0
360 		if ndigits < 0:
361 			exponent = 10 ** (-ndigits)
367 			exponent = _decimal.Decimal('10') ** (-ndigits)
383 		def round3(number, ndigits=None):  argument
384 			return _round(number) if ndigits is None else _round(number, ndigits)
393 	def round3(number, ndigits=None):  argument
414 		if ndigits is None:
415 			ndigits = 0
426 		m = number * (10 ** ndigits)
430 			if ndigits < 0:
431 				exponent = 10 ** (-ndigits)
438 				exponent = _decimal.Decimal('10') ** (-ndigits) if ndigits != 0 else 1
444 			d = round2(number, ndigits)