[Python知识库]python编程 从入门到实践 第五章 if语句

cars=['audi','bmw','subaru','toyota']
for car in cars:
	if car=="bmw":
		print(car.upper())
	else:
		print(car.title())

#检查是否相等时，会忽略大小写
car='subaru'
print("Is car=='subaru'? I predict True.")
print(car=='subaru')

age=17
if age>=18:
	print("You are old enough to vote!!!")
	print("Have you registered to vote yet?")
else:
	print("Sorry,you are too young to vote.")

#if elif else
age=12
if age<4:
	print('免费')
elif 4<=age<=18:
	print("请缴费25美元")
else:
	print("请缴费40美元")

#if if if
favorite_fruits=["苹果","橘子","香蕉"]
if "苹果" in favorite_fruits:
	print("you really like 苹果")
if '橘子' in favorite_fruits:
	print("you really like 橘子")
if '香蕉' in favorite_fruits:
	print("you really like 香蕉")

#查看列表的值
requested_toppings=[]
if requested_toppings:
	for requested_topping in requested_toppings:
		print(f"adding {requested_topping}.")
else:
	print('Are you sure you want a plain pizza')

#在python3.7以后，字典中的元素排列顺序与定义时相同（添加字典元素）
alien_0={'color':'green','options':5}
print(alien_0['color'])
print(alien_0['options'])
 
alien_0['x_position']=0
alien_0['y_position']=25
print(alien_0)#{'color': 'green', 'options': 5, 'x_position': 0, 'y_position': 25}