一、使用装饰器实现单例

def Singleton(cls):
    _instance = {}

    def _singleton(*args, **kargs):
        if cls not in _instance:
            _instance[cls] = cls(*args, **kargs)
        return _instance[cls]

    return _singleton


@Singleton
class A(object):
    a = 1

    def __init__(self, x=0):
        self.x = x


a1 = A(2)
a2 = A(3)

二、web自动化driver实现单例模式

2.1 编写单例模式的装饰器

singleton.py

#coding:utf-8
#单例模式函数，用来修饰类
def singleton(cls,*args,**kw):
    instances = {}
    def _singleton():
        if cls not in instances:
            instances[cls] = cls(*args,**kw)
        return instances[cls]
    return _singleton

2.2 driver 使用装饰器，实现单例模式

GetSeleniumDriver.py

# -*- coding:utf-8 -*-
from selenium import webdriver
from singleton import singleton
@singleton
class GetSeleniumDriver(object):
    def __init__(self):
        self.driver = webdriver.Chrome()

2.3 获取driver的实例，就是单例了

class My_task(RES):
    def __init__(self):
        self.driver=GetSeleniumDriver().driver

    def Making_task_Button(self):
        Making_task_Button=self.driver.find_element_by_xpath(RES.Making_task_Button_xpth)
        return Making_task_Button

    def Audit_task_Button(self):
        Audit_task_Button=self.driver.find_element_by_xpath(RES.Audit_task_Button_xpth)
        return Audit_task_Button