Python input用户输入

函数input()的工作原理

• 函数input()让程序暂停运行，等待用户输入一些文本，获取用户输入后，python将其变量存储在一个变量中，以方便实用。
• input()接收一个参数，即向用户显示的提示或说明。

# 案例1
message = input("Tell me something,and I will repaeat it back to you : ")
print(message)

Tell me something,and I will repaeat it back to you : hello
hello

编写清晰的程序

• 使用input()函数时，都应指向清晰而易于明白的提示。
• 可将提示存储在一个变量中，再将变量传递给函数input()

name = input("Please enter your name: ")
print("Hello, " + name + "!")

Please enter your name: yegeli
Hello, yegeli!

prompt = "If you tell us who you are, we can personalize the message you see. "
prompt += "\nWhat is your first name? "
name = input(prompt)
print("\nHello, " + name + "!")

If you tell us who you are, we can personalize the message you see. 
What is your first name? yegeli

Hello, yegeli!

使用int()来获取数值输入

• 用户输入的数值为字符串表示
• 函数int()将数字的字符串表示转换为数值表示
• 将数值输入用于计算和比较前，务必将其转换为数值表示

age = input("How old are you? ")
age

How old are you? 21





'21'

age = input("How old are you ? ")
age = int(age)
age >=18

How old are you ? 21





True

height = input("How tall are you ,in inches? ")
height = int(height)

if height >= 36:
    print("\nYou're tall enough to ride!")
else:
    print("\nYou'll be able to ride when you're a little order.")

How tall are you ,in inches? 30

You'll be able to ride when you're a little order.

求模运算符

• % 它将两个数想出并返回余数：
• 一个数可被另一个数整除，余数就为 0 ，因此求模运算符将返回 0 。你可利用这一点来判断一个数是奇数还是偶数

# 奇数偶数判断
number = input("Enter a number, and I'll tell you if it's enven or odd: ")
number = int(number)

if number % 2 == 0:
    print("\nThe number " + str(number) + " is even")
else:
    print("\nThe number " + str(number) + " is odd")

Enter a number, and I'll tell you if it's enven or odd: 22

The number 22 is even

练习

# 1.汽车租赁
# 编写一个程序，询问用户要租赁什么样的汽车，并打印一条消息，如 “Let me see if I can find you a Subaru”
prompt = "brother，DO you want to rent a car? "
message = input(prompt)
print("Let me see if I can fin you a " + message.title() + " !")

brother，DO you want to rent a car? subaru
Let me see if I can fin you a Subaru !

# 2.餐馆订位
# 编写一个程序，询问用户有多少人用餐。如果超过 8 人，就打印一条消息，指出没有空桌；否则指出有空桌。
order_food = input("How many people order meals? ")
order_food = int(order_food)
if order_food >= 8:
    print("Sorry there are no vacant tables.")
else:
    print("\nGreat,there are still tables available.")

How many people order meals? 4

Great,there are still tables available.

# 3.10的整数倍
# 让用户输入一个数字，并指出这个数字是否是 10 的整数倍
multiple = input("Please enter a number! ")
multiple = int(multiple)
if multiple % 10 == 0:
    print(str(multiple) + " is 10 multiple.")
else:
    print(str(multiple) + " is not 10 multiple.")

Please enter a number! 110
110 is 10 multiple.