Checkio 题目求赐教：关于检查序列是否为空

本人在解决检查序列是否为空白的时候用了 if args is None:语句，但 IDE 却返回我的错误是 max （）函数里边的参数为空。后来我在网上找了 if not args:却解决问题了，求有深入了解大佬解释一下。源代码如下。

def checkio(*args): if args is None: #if not args: return 0 #"Empty" else: max_num = max(args) min_num = min(args) answer = max_num - min_num print ("%s-%s=%s" % (max_num, min_num, answer)) return answer

#These "asserts" using only for self-checking and not necessary for auto-testing if name == 'main': def almost_equal(checked, correct, significant_digits): precision = 0.1 ** significant_digits return correct - precision < checked < correct + precision

assert almost_equal(checkio(1, 2, 3), 2, 3), "3-1=2"
assert almost_equal(checkio(5, -5), 10, 3), "5-(-5)=10"
assert almost_equal(checkio(10.2, -2.2, 0, 1.1, 0.5), 12.4, 3), "10.2-(-2.2)=12.4"
assert almost_equal(checkio(), 0, 3), "Empty"
print("Coding complete? Click 'Check' to review your tests and earn cool rewards!")