python装饰器相当于函数的调用方式

1. 普通装饰器

import logging

1. foo = use_loggine(foo)
def use_loggine(func):
def wrapper():
 logging.warn("％s is running " ％ func.__name__)
 return func()
return wrapper

@use_loggine
def foo():
print "aaa"
foo()
print foo.__name__

2. func 需要参数：

foo = use_loggine(foo) 第一个参数就是func这个函数对象，不包含参数foo(params)

def use_loggine(func):
def wrapper(name):
 logging.warn("％s is running " ％ func.__name__)
 return func(name)
return wrapper

@use_loggine
def foo(name):
print "name is ％s" ％ name

3. 装饰器带参数

foo = use_logging('warn')(foo) 还是把被装饰的函数当做参数赋给装饰器

def use_logging(level):
def decorator(func):
def wrapper(*args, **kwargs):
 if level == 'warn':
 logging.warn("％s is running" ％ func.__name__)
 elif level == 'info':
 logging.warn("％s is running" ％ func.__name__)
 return func(*args)
return wrapper
return decorator

@use_logging('warn')
def foo(name):
print "i am ％s" ％ name

foo = use_logging('warn')(foo)
print foo.__name__
foo('foo')

4. 类装饰器，还是把被装饰的函数当做参数赋给装饰器

foo = Foo(params)(func)

class Foo(object):
def __init__(self, name):
self.name = name

def __call__(self, func):
def aa():
 print "class decorator running"
 print "name is :％s" ％ self.name
 func()
 print 'class decorator ending'
return aa

@Foo("hello")
def bar():
print "world"

bar()

@deco
def foo()
pass

foo = deco(foo)

@deco(xx)
def foo():
pass

foo = deco(xx)(foo)

5. 类方法装饰器

类方法装饰器和其他装饰器没有什么区别，只不过在装饰器内部返回的函数中，第一个参数是固定的，是调用方法的对象本身，如

果是实例对象，就是self，是类方法的话，就是cls，静态方法的话，没有第一个参数。

from functools import wraps

def method_decor(func):
@wraps(func)
def wrapper(*args, **kwargs):
 try:
 u = func(*args, **kwargs)
 return u
 except Exception as e:
 args[0].bb() # args[0]就是self或者cls。可以在args前面定义self，更加方便u = func(self，*args, **kwargs)
 return 'an Exception raised.'

return wrapper

class Foo(object):

@method_decor
def aa(self):
 # print("This is wraped method")
 raise Exception('aa')

def bb(self):
 print("This is called method")

a = Foo()
a.aa()

来源：https://blog.csdn.net/vwangyanwei/article/details/82629780