Chapter 5: if Statement

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

Python在条件判断时大小写敏感

a = 'H'
a == h  # False

不等 !=
逻辑与 and
逻辑或 or
判断一个值是否在list里 in
判断一个值是否在list里 not in
布尔值首字母大写 True False

if - elif -else

age = 4
if age < 4:
    print("Your admission cost is $0.")
elif age < 18:
    print("Your admission cost is $25.")
else:
    print("Your admission cost is $40.")

在Python中，最后的else判断不是必须的

判断list是否为空

requested_toppings = []
if requested_toppings:
    print('Y')
else:
    print('N')

代码风格：
运算符两边要有空格

if a == 4: