闭包函数与装饰器

def f1():
    name=‘good‘
    def f2():
        print(name)
    return f2     

包两层

def aaa():
    name=‘egon‘
    def wrapper():
        money=1000
        def tell_info():
            print(‘egon have money %s‘ %(money))
            print(‘my namn is %s‘ %name)
        return tell_info
    return wrapper

w=aaa()
tell_info=w()
print(tell_info.__closure__[0].cell_contents)
print(tell_info.__closure__[1].cell_contents)

‘‘‘
报错NameError: name ‘money‘ is not defined

原因：
    函数的作用域关系在函数定义阶段就已经固定，与调用位置无关
    无论函数在何处调用，都需要回到定义阶段去找对应的作用域关系
    此例：虽然tell_info(‘egon‘)是在foo内调用并且引用money，但仍需要回到定义
    tell_info的阶段去找作用域关系，而定义时tell_info引用的money就是全局的money
    如果全局不存在则抛出异常NameError

‘‘‘

#装饰器修订
import time
import random
#装饰器
def timmer(func):
    def wrapper(*args,**kwargs):
        start_time = time.time()
        res=func(*args,**kwargs)
        stop_time=time.time()
        print(‘run time is %s‘ %(stop_time-start_time))
        return res
    return wrapper
#被装饰函数

@timmer
def index():
    time.sleep(random.randrange(1,5))
    print(‘welecome to index page‘)

@timmer
def home(name):
    time.sleep(random.randrange(1,3))
    print(‘welecome to %s HOME page‘ %name)
    return 123123123123

index()

#加多个装饰器
import time
import random
#装饰器
def timmer(func):
    def wrapper():
        start_time = time.time()
        func()
        stop_time=time.time()
        print(‘run time is %s‘ %(stop_time-start_time))
    return wrapper
def auth(func):
    def deco():
        name=input(‘name: ‘)
        password=input(‘password: ‘)
        if name == ‘egon‘ and password == ‘123‘:
            print(‘login successful‘)
            func() #wrapper()
        else:
            print(‘login err‘)
    return deco

#被装饰函数
@auth #index=auth(wrapper) #index=deco                      #index=auth(wrapper) #index=deco
@timmer #index=timmer(index) #index=wrapper
def index():
    # time.sleep(random.randrange(1,5))
    time.sleep(3)
    print(‘welecome to index page‘)


def home():
    time.sleep(random.randrange(1,3))
    print(‘welecome to HOME page‘)

# index() #deco()
# home()