Python3.5裝飾器原理及應(yīng)用實(shí)例詳解

import time
#統(tǒng)計(jì)函數(shù)運(yùn)行時(shí)間的磚裝飾器
def timmer(func):
  def warpper(*args,**kwargs):
    strat_time = time.time()
    func()
    stop_time = time.time()
    print("the func run time is %s" %(stop_time-strat_time))
  return warpper
@timmer
def test1():
  time.sleep(3)
  print("in the test1")
test1()
 

def bar():
  print("in the bar")
def foo():
  print("in the foo")
  bar()
foo()
#python為解釋執(zhí)行，函數(shù)foo在調(diào)用前已經(jīng)聲明了bar和foo，所以bar和foo無順序之分
def foo():
  print("in the foo")
  bar()
def bar():
  print("in the bar")
foo()

def bar():
  print("in the bar")
def test1(func):
  print(func)  #打印門牌號(hào)，即內(nèi)存地址
  func()
test1(bar)   #門牌號(hào)func=bar

import time
def bar():
  time.sleep(3)
  print("in the bar")
#test2在不修改被修飾函數(shù)bar的代碼時(shí)添加了附加的及時(shí)功能
def test2(func):
  start_time = time.time()
  func()   #run bar
  stop_time = time.time()
  print("the func run time is %s " %(stop_time-start_time))
#調(diào)用方式發(fā)生改變，不能像原來的方法去調(diào)用被修飾的函數(shù)（所以不能實(shí)現(xiàn)裝飾器的功能）
test2(bar)
#bar()

import time
def bar():
   time.sleep(3)
   print("in the bar")
def test3(func):
  print(func)
  return func
bar = test3(bar)
bar()  #run bar

#函數(shù)嵌套
def foo():
  print("in the foo")
  def bar():  #bar函數(shù)具有局部變量的特性，不能在外部調(diào)用,只能在內(nèi)部調(diào)用
    print("in the bar")
  bar()
foo()

#!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author:ZhengzhengLiu
#模擬網(wǎng)站，訪問頁(yè)面和部分需要登錄的頁(yè)面
import timer
user,passwd = "liu","liu123"
def auth(func):
  def wrapper(*args,**kwargs):
    username = input("Username:").strip()
    password = input("Password:").strip()
    if username == user and password == passwd:
      print("\033[32;1mUser has passed authentication!\033[0m")
      res = func(*args,**kwargs)
      print("-----after authentication---")
      return res
    else:
      exit("\033[31;1mInvalid username or password!\033[0m")
  return wrapper
def index():
  print("welcome to index page!")
@auth
def home():
  print("welcome to index home!")
  return "from home"
@auth
def bbs():
  print("welcome to index bbs!")
#函數(shù)調(diào)用
index()
print(home())
bbs()
 

#!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author:ZhengzhengLiu
#模擬網(wǎng)站，訪問頁(yè)面和部分需要登錄的頁(yè)面，多種認(rèn)證方式
import timer
user,passwd = "liu","liu123"
def auth(auth_type):
  print("auth func:",auth_type)
  def outer_wrapper(func):
    def wrapper(*args, **kwargs):
      print("wrapper func args:",*args, **kwargs)
      if auth_type == "local":
        username = input("Username:").strip()
        password = input("Password:").strip()
        if username == user and password == passwd:
          print("\033[32;1mUser has passed authentication!\033[0m")
          #被裝飾的函數(shù)中有返回值，裝飾器中傳入的參數(shù)函數(shù)要有返回值
          res = func(*args, **kwargs)  #from home
          print("-----after authentication---")
          return res
        else:
          exit("\033[31;1mInvalid username or password!\033[0m")
      elif auth_type == "ldap":
        print("ldap....")
    return wrapper
  return outer_wrapper
def index():
  print("welcome to index page!")
@auth(auth_type="local")    #利用本地登錄 home = wrapper()
def home():
  print("welcome to home page!")
  return "from home"
@auth(auth_type="ldap")    #利用遠(yuǎn)程的ldap登錄
def bbs():
  print("welcome to bbs page!")
#函數(shù)調(diào)用
index()
print(home())   #wrapper()
bbs()