CS50P: 1. Conditionals
运算符
python中有 >= 和 <= ，其余和C一样
python支持 90 <= score <= 100
| C | Python |
|---|---|
| || | or |
| & | and |
布尔运算
True or False
选择语句
if
if x < y:
print("x is less than y")
if x > y:
print("x is greater than y")
if x == y:
print("x is equal to y")
:....四个缩进，表示只有当if为真，该语句才能被执行。有缩进是一个代码块
代码的逻辑：三个 if 都会被执行
elif
if x < y:
print("x is less than y")
elif x > y:
print("x is greater than y")
elif x == y:
print("x is equal to y")
else
if x < y:
print("x is less than y")
elif x > y:
print("x is greater than y")
else:
print("x is equal to y")
match
类似 switch
原：
if name == "Harry" or name == "Hermione" or name == "Ron": #字符串 ==
print("Gryffindor")
elif name == "Draco":
print("Slytherin")
else:
print("Who?")
match：
match name:
case "Harry" | "Hermione" | "Ron":
print("Gryffindor")
case "Draco":
print("Slytherin")
case _:
print("Who?")
case _:表示else|在case中表示或
Pythonic Expressions
def is_even(x):
return True if x % 2 == 0 else False
def is_even(x):
return x % 2 == 0