# -*- coding: utf-8 -*-
from collections.abc import Iterable

def findMinAndMax(L):
	if len(L) == 0:
		return (None, None)
	elif isinstance(L, Iterable):
		maxnum = L[0]
		minnum = L[0]
		for i in L:
			if i > maxnum:
				maxnum = i
			elif i < minnum:
				minnum = i

		return (minnum, maxnum)


# 测试
if findMinAndMax([]) != (None, None):
    print('测试失败!')
elif findMinAndMax([7]) != (7, 7):
    print('测试失败!')
elif findMinAndMax([7, 1]) != (1, 7):
    print('测试失败!')
elif findMinAndMax([7, 1, 3, 9, 5]) != (1, 9):
    print('测试失败!')
else:
    print('测试成功!')