Pyhton 装饰器

Posted 2021-03-15 ray-2019

# -*- coding:utf8 -*-
# Author : Mr·Yang

‘‘‘
    装饰器，带参数装饰器，装饰器中带参数
‘‘‘

---

import time

# 普通装饰器
‘‘‘
def time_decor(func):
    def wrapper():
        star_time = time.time()
        func()
        down_time = time.time()
        print("总耗时为", down_time - star_time)

    return wrapper

@time_decor
def wait():
    time.sleep(2)
    
if __name__ == ‘__main__‘:
    wait()
‘‘‘

# 被装饰函数带参数
‘‘‘
def time_decor(func):
    def wrapper(name):
        star_time = time.time()
        func(name)
        down_time = time.time()
        print("总耗时为", down_time - star_time)

    return wrapper

@time_decor
def wait(name):
    print("这是{}带参数的装饰器".format(name))
    time.sleep(2)


if __name__ == ‘__main__‘:
    name = "yanglei"
    wait(name)

---

# 带参数的装饰器

def time_decor(cond):
    def external(func):
        def wrapper():
            if cond == "True":
                star_time = time.time()
                func()
                down_time = time.time()
                print("总耗时为", down_time - star_time)
            else:
                print("33[31;1m这是啥也没干的33[0m")
                func()

        return wrapper

    return external


@time_decor(cond="False")
def wait():
    time.sleep(2)

if __name__ == ‘__main__‘:
    wait()

---

# 装饰器和被装饰函数都带参数

def time_decor(cond):
    def external(func):
        def wrapper(*args, **kwargs):
            if cond == "True":
                star_time = time.time()
                func(*args, **kwargs)
                down_time = time.time()
                print("总耗时为", down_time - star_time)
            else:
                print("33[31;1m这是啥也没干的33[0m")
                func()

        return wrapper

    return external


@time_decor(cond="True")
def wait(*args, **kwargs):
    print(len(args))
    if len(args) > 1:
        time.sleep(2)
        if args[0]==1:
            print(123)
    else:
        print(args)
if __name__ == ‘__main__‘:
    name, age, sun = 1, 2, 3
    wait(name, age, sun)

---

# 被装饰函数带返回值
def time_decor(func):
    def wrapper(*args, **kwargs):
        if func(*args, **kwargs) == None:
            print("没有返回值的函数对象")
        else:

            print("带返回值的函数对象")
            res = func(*args, **kwargs)
            return res

    return wrapper


@time_decor
def wait(*args, **kwargs):

    sun = args[0]+args[1]
    return sun


if __name__ == ‘__main__‘:
    x = 111
    y = 222
    a = wait(x,y)
    print(a)
‘‘‘


#

def time_decor(func):
    def wrapper():
        start_time = time.time()
        func()
        down_time = time.time()

    return wrapper


import threading
import time


def time_out(timer):
    ‘‘‘
    一个规定函数执行时间的装饰器
    :param timer:
    :return:
    ‘‘‘

    def wrapper(func):
        def __wrapper():
            start_time = time.time()
            # 通过设置守护线程强制规定函数的运行时间
            t = threading.Thread(target=func)

            t.setDaemon(True)
            t.start()
            time.sleep(timer)
            if t.is_alive():
                # 若在规定的运行时间未结束守护进程，则主动抛出异常
                raise Exception(‘Function execution timeout‘)
            print (time.time()-start_time)

        return __wrapper

    return wrapper


@time_out(50)
def timer():
    time.sleep(10)


timer()