pyspider中every,config装饰器的实现原理

import requests
import time
url = 'http://www.baidu.com'

# 不含参数的装饰器，两个套
def alltime(func):
    def wrapper(*args,**kwargs):
        start = time.time()
        content = func(*args,**kwargs)
        print(time.time() - start)
        return content
    return wrapper

@alltime
def request():
    content = requests.get(url)
    return content


# 含参数的装饰器，三个套
def out(canshu):
    def cehi(func):
        def wrapper(*args,**kwargs):
            # 可以理解为闭包中的global,在内部函数中修改外部函数的值
            nonlocal canshu
            while int(canshu) < 100:
                start= time.time()
                time.sleep(2)
                content = func(*args,**kwargs)
                print('本次用时%s' % (time.time()-start))
                canshu = int(canshu) + 1
                # 被装饰的函数有返回值的情况下需要返回
                return content
        return wrapper
    return cehi

@out(canshu=30)
def xx():
    print(123)

xx()