[Python知识库]学习Python单利模式

首先创建三个py文件

danli.py

import threading


class Singleton(object):
    _lock = threading.Lock()

    lit = []

    def __new__(cls, *args, **kwargs):
        if not hasattr(Singleton, "_instance"):
            with Singleton._lock:    # 加锁防止多线程环境中两个线程同时判断到上一行代码为True，同时创建该类的实例
                if not hasattr(Singleton, "_instance"):
                    # 调用object类的__new__方法
                    Singleton._instance = super(Singleton, cls).__new__(cls, *args, **kwargs)
        return Singleton._instance.lit

ceshi.py

from danli import Singleton

def run():

    test = Singleton()

    test.append(1)

    print(test)

    test.append(2)

    print(test)

ceshi1.py

from danli import Singleton
from ceshi import run

test = Singleton()

run()

test.append(3)

print(test)

执行ceshi1.py结果为：

[1]
[1, 2]
[1, 2, 3]

如有不足，还请多多指正。
参考python中的单例模式实现