装饰器

柔光的暖阳◎ 2023-10-10 10:16 49阅读 0赞

# 装饰器 #

### 定义: ###

用来装饰的工具

在不改变源代码及调用方式的基础上额外增加新的功能

开放封闭原则:

扩展是开放的(增加新功能)

修改源码是封闭的(修改已经实现的功能)

### 版一: ###

import time start_time = time.time() def func(): time.sleep(2) print("asdf") func() print(time.time() - start_time) start_time = time.time() def foo(): time.sleep(3) print("qwer") foo() print(time.time() - start_time)

### 版二: ###

def times(f): start_time = time.time() f() print(time.time() - start_time) def foo(): time.sleep(3) print("asdf") s = foo foo = times foo(s)

### 版三(初识版装饰器): ###

def times(f): def inner(): start_time = time.time() f() print(time.time() - start_time) return inner def foo(): time.sleep(1) print("asdf") foo = times(foo) foo()

### 版四(第二版装饰器): ###

def wrapper(): def inner(): print(1) return inner print(wrapper()()) def wrapper(f): def inner(): f() return inner def func(): print("123456") func = wrapper(func) func()

### low版 ###

import time def wrapper(f): def inner(*args,**kwargs): start_time = time.time() f(*args,**kwargs) print(time.time() - start_time) return inner def func(*args,**kwargs): print(f"这是{args,kwargs}函数") time.sleep(2) func = wrapper(func) func("alex","wusir")

### 高级版: ###

import time def wrapper(f): def inner(*args,**kwargs): start_time = time.time() f(*args,**kwargs) print(time.time() - start_time) return inner @wrapper def func(*args,**kwargs): print(f"这是{args,kwargs}函数") time.sleep(2) @wrapper def foo(*args,**kwargs): print(f"这是{args,kwargs}函数,123456") time.sleep(3) func("alex","ahfe") foo("alex1","faikewfhn")

### 标准版: ###

def func(a): #a是要被装饰的函数名 def foo(*args,**kwargs): "装饰之前的操作" ret = a(*args,**kwargs) "装饰之后的操作" return ret return foo @func def f1(*args,**kwargs): print(f"这是一个{args}") return "我可以返回了" f1(1,2,3,34,4,5)

#### 语法糖 ####

语法糖必须放在被装饰的函数正上方

@wrapper 就等于 func = wrapper(func) @wrapper 就等于 foo = wrapper(foo)

转载于:https://www.cnblogs.com/beichen123/p/11247130.html