链式

class person:
    def name(self,name):
        self.name = name
        return self
    def age(self,age):
        self.age = age
        return self
    def show(self):
        print(f"my name is {self.name},and i am {self.age}")

装饰器

1. 函数装饰器

def print_args(function):
    def wrapper(*args,**kwargs):
        print(f"function => {function.__name__};argument => {args},{kwargs}")
        return function(*args,**kwargs)
    return wrapper

bool value is false

False    None    0   ""    ()    []   {}

these bool values are false. you can use when needing to judge var if was empty

if not a:
  ...

随机获取list值

a = [1,2,3,4]
random.choice(a)
``