Python if语句

1.if-else语句

【实例】：

number = 30
if number >20:
    print("bigger")
else:
    print("smaller")

【运行结果】：

bigger

 

2.if-elif-else语句

【实例】：游乐场按年龄收取门票：4岁以下免票；4到18岁10元；18岁以上20元。

age = 12
if age < 4 :
    print("免费")
elif age < 18 :
    print("10元票价")
else :
    print("20元票价")

【运行结果】：

10元票价

 

3.检查特定值是否在列表

【实例】：

countries = ['china','america','england']
if 'russia' in countries:
    print("russia √")
elif 'england' in countries:
    print("england √")

【运行结果】：

england √

 

4.例题：售卖水果

【实例】：

needs = ['apple','pear','lemon'] 
fruit_shops = ['apple','pear','banana']
for need in needs:
    if need in fruit_shops:
        print(f"It is your {need}")
    else:
        print(f"sorry,we don't have {need}")

【运行结果】：

It is your apple
It is your pear
sorry,we don't have lemon