python小测验3_python基础小测试

def is_int(int_num):

""" check whether int_num is integer! """

if isinstance(int_num, str): # 判断是否为字符串类型

if int_num.isdigit():

return True

else:

return False

elif isinstance(int_num, int): # 判断是否为整数类型

return True

else:

return False

def count_factorial(one_num):

""" count one_num's fatorial """

result = 1

if one_num < 0:

print("{}为负数，没有阶乘！".format(one_num))

return None

elif one_num in (0, 1):

return 1

else:

for i in range(1, one_num + 1):

result *= i

return result

input_num = input("请输入一个正整数：")

if is_int(input_num):

input_num = int(input_num)

print("{}的阶乘为：{}".format(input_num, count_factorial(input_num)))

else:

print("输入的{}有误，请输入一个正整数!".format(input_num))