python怎么定义用户输入

#!/usr/bin/python3

usr_ip = input("Enter an integer number: ")

usr_num = int(usr_ip)

sqr_num = usr_num * usr_num

print("Square of entered number is: {}".format(sqr_num))

$ ./user_input_int.py

Enter an integer number: 23

Square of entered number is: 529

$ ./user_input_int.py

Enter an integer number: abc

Traceback (most recent call last):

  File "./user_input_int.py", line 6, in <module>

    usr_num = int(usr_ip)

ValueError: invalid literal for int() with base 10: 'abc'

#!/usr/bin/python3

usr_ip = input("Enter a floating point number: ")

# 需要将输入的字符串显式地指定为我们需要的类型

usr_num = float(usr_ip)

sqr_num = usr_num * usr_num

# 限制小数点位数

print("Square of entered number is: {0:.2f}".format(sqr_num))

$ ./user_input_float.py

Enter a floating point number: 3.232

Square of entered number is: 10.45

$ ./user_input_float.py

Enter a floating point number: 42.7e5

Square of entered number is: 18232900000000.00

$ ./user_input_float.py

Enter a floating point number: abc

Traceback (most recent call last):

  File "./user_input_float.py", line 6, in <module>

    usr_num = float(usr_ip)

ValueError: could not convert string to float: 'abc'

#!/usr/bin/python3

usr_name  = input("Hi there! What's your name? ")

usr_color = input("And your favorite color is? ")

print("{}, I like the {} color too".format(usr_name, usr_color))

$ ./user_input_str.py

Hi there! What's your name? learnbyexample

And your favorite color is? blue

learnbyexample, I like the blue color too