一沥邻、函數(shù)傳參

def t1():
    print "t1"

def t2(func):
    print func     # <function t1 at 0x10aae2668>
    func()         # 輸出t1
    print "t2"     # 輸出t2

t2(t1)

二、如果每個(gè)函數(shù)都需要同一個(gè)功能

def log(func):
    print "logging ..."
    func()

def foo():
    print "this is foo"

def bar():
    print "this is bar"

log(bar)   
#在實(shí)際函數(shù)外包裹一個(gè)功能函數(shù)羊娃，破壞了代碼結(jié)構(gòu)唐全，很復(fù)雜

三、裝飾器實(shí)現(xiàn)

def log(func):
    def wrapper():
        print "logging ..."
        func()
    return wrapper

@log
def foo():
    print "this is foo"

@log
def bar():
    print "this is bar"

bar()    #先進(jìn)入log函數(shù)蕊玷，返回wrapper時(shí)進(jìn)入wrapper執(zhí)行print芦瘾，執(zhí)行func函數(shù)
foo()

四、被裝飾函數(shù)有參數(shù)情況

def log(func):
    def wrapper(*args):
        print "logging ..."
        func(*args)
    return wrapper

@log
def foo(name,age):
    print "this is %s" %name
    print "he is %d" %age


foo("abc",99)

####################################################
def log(func):
    def wrapper(*args, **kwargs):
        # args是一個(gè)參數(shù)數(shù)組集畅，kwargs一個(gè)關(guān)鍵字字典
        print "logging ..."
        func(*args, **kwargs)
    return wrapper

@log
def foo(*args, **kwargs):
    for arg in args:
        print arg

    for k, v in kwargs.items():
        print k, v


foo(1,2,3,name='abc',age=99)

五近弟、帶參數(shù)的裝飾器

def log(level):
    def decorator(func):
        def wrapper(**kwargs):
            if level==1:
                print "logging level = 1..."
            else:
                print "logging level != 1..."
            func(**kwargs)
        return wrapper
    return decorator

@log(level=2)
def foo(**kwargs):
    print "this is %s" % kwargs['name']
    print "he is %d" % kwargs['age']


foo(name='abc', age=99)

六、類(lèi)裝飾器

主要通過(guò)call函數(shù)進(jìn)行調(diào)用

class Log():
    def __init__(self,func):
        self.func=func

    def __call__(self, **kwargs):
        print "logging use decorator class"
        self.func(**kwargs)
        print "decorator class end"

@Log
def foo(**kwargs):
    print "this is %s" % kwargs['name']
    print "he is %d" % kwargs['age']


foo(name='abc', age=99)

七挺智、多個(gè)裝飾器

def a(func):
    def wrapper():
        print "aaaa"
        return func()
    return wrapper

def b(func):
    def wrapper():
        print "bbbb"
        return func()
    return wrapper

def c(func):
    def wrapper():
        print "cccc"
        return func()
    return wrapper

@a
@b
@c
def foo():
    print "this is foo"


foo()  # 先a祷愉，再b，再c赦颇，再foo

其他：裝飾器簡(jiǎn)單實(shí)例

#coding:utf-8

import time
"""
裝飾器器：先進(jìn)入裝飾器器二鳄，func就是now函數(shù)
"""
def log1(func):
    def wrapper(*args, **kw):
        print "call,",func.__name__
        func()
    return wrapper
#log1：返回wrapper時(shí)，進(jìn)入wrapper媒怯，執(zhí)行print订讼，然后執(zhí)行func
#>>> call,now
#>>> 152.....

def log2(func):
    def wrapper(*args, **kw):
        print "call,",func.__name__
    func()
    return wrapper
#log2：先執(zhí)行func，再在返回wrapper時(shí)扇苞，進(jìn)入wrapper欺殿，執(zhí)行print
#>>> 152.....
#>>> call,now

@log1
def now():
    print time.time()

now()
# 本質(zhì)上 log1(now)