1. if语句
# _*_ coding:utf8 _*_
# if 语句
age = 19
if age >= 18:
print("you are my choose")
# if-else语句
age = 17
if age >= 18:
print("you are my choose")
print(" have you already register?")
else:
print("you are not my choose")
print("sorry,")
# if-elif-else结构
age = 12
if age <= 4:
print("free")
elif 18 >= age > 4:
print("five")
else:
print("ten")
# 使用多个 elif语句判断
age = 10
if age <= 4:
print(" fighting,free")
elif 13 >= age > 4:
print("two")
elif 18 >= age > 13:
print("ten")
else:
print("bad,bad")
# 省略else 语句 Python中 if-elif结构中并不要求必须写else语句,在有些情况下可以不用else
age = 29
if age < 4:
price = 0
elif age < 18:
price = 5
elif age < 65:
price = 10
elif age > 65:
price = 5
print(" your price is " + str(price))
# 如果你想执行一个代码块,就是使用 if-elif-else 结构,如果你都想使用那么,你就使用多个if结构的
2. if操作列表
# _*_ coding:utf8 _*_
# if语句操作列表
# 操作特殊元素
request_toppings = ['you', 'he', 'her', 'she', 'my']
for request_topping in request_toppings:
if request_topping == 'she':
print('sorry ' + request_topping)
else:
print(request_topping)
# 确定列表不是为空的
# 当列表的长度大于1的时候 用if判断就会返回 True 为空就会返回False
request_toppings = []
if request_toppings:
print(" sorry is null")
else:
print(" is not null")
# 使用多个列表 循环嵌套 条件判断
one = ['one','two','three','four','five','six']
two = ['five','eight','ten','seven']
for value in one:
if value in two:
print(value)
else:
print('sorry')