Python is 和 == 区别 - Python零基础入门教程

古城微笑少年丶 2022-10-05 06:57 185阅读 0赞

*  一.前言
 *  二.Python 运算符 ==
 *  三.Python 运算符 is
 *  四.猜你喜欢

> 零基础 Python 学习路线推荐 : [Python 学习目录][Python] >> [Python 基础入门][Python 1]

在 Python 中 is 和==都说常用的运算符之一，主要用于检测两个变量是否相等，返回 True 或者 False ，具体区别在哪呢？

## 一.前言 ##

在讲解 [**is 和 == 区别**][is _ _]直接先讲解一下\*\*[内置函数 id][is _ _]\*\*，其实在文章 **[Python 可变数据类型和不可变数据类型][Python 2]** 中也对内置函数 id 有过讲解，主要用于获取[变量][Link 1]的内存地址！关于内存现在不做过多讲解，你可以把内存地址当作一串数字符号，内存地址就好比每个人都有一个身份证号码一样！

# !usr/bin/env python
    # -*- coding:utf-8 _*-
    """
    @Author:猿说编程
    @Blog(个人博客地址): www.codersrc.com
    @File:Python is 和 == 区别.py
    @Time:2021/3/25 23:00
    @Motto:不积跬步无以至千里，不积小流无以成江海，程序人生的精彩需要坚持不懈地积累！
    
    """
    
    a = 5
    b = False
    c = "hello"
    
    print("a内存地址：{}".format(id(a)))
    print("b内存地址：{}".format(id(b)))
    print("c内存地址：{}".format(id(c)))
    
    '''
    输出结果：
    a内存地址：1784504608
    b内存地址：1784012992
    c内存地址：2126520897696
    
    '''

## 二.Python 运算符 == ##

**如果两个变量的值相等，那么运算符 == 成立，返回 True ；反之返回 False** ；示例代码如下：

# !usr/bin/env python
    # -*- coding:utf-8 _*-
    """
    @Author:猿说编程
    @Blog(个人博客地址): www.codersrc.com
    @File:Python is 和 == 区别.py
    @Time:2021/3/25 23:00
    @Motto:不积跬步无以至千里，不积小流无以成江海，程序人生的精彩需要坚持不懈地积累！
    
    """
    
    a = 3
    b = 3
    print(a==b)
    
    # 整数与浮点数的比较
    a = 3
    b = 3.0
    print(a==b)
    
    a = 3
    b = 2.9999
    print(a==b)
    
    # 字符串比较
    a = "hello world"
    b = "HELLO WORLD"
    c = "hello "
    d = "hello world"
    print(a==b,a==c,b==c,a==d)
    
    '''
    输出结果：
    True
    True
    False
    False False False True
    '''

## 三.Python 运算符 is ##

*  **1.两个变量的值相等；**
 *  **2.变量地址也相同(可以通过内置函数 id 获取变量内存地址)；**

如果同时满足以上两个条件，运算符 is 才成立，返回 True ；反之，不满足其中任何一个条件都会返回 False ；示例代码如下：

# !usr/bin/env python
    # -*- coding:utf-8 _*-
    """
    @Author:猿说编程
    @Blog(个人博客地址): www.codersrc.com
    @File:Python is 和 == 区别.py
    @Time:2021/3/25 23:00
    @Motto:不积跬步无以至千里，不积小流无以成江海，程序人生的精彩需要坚持不懈地积累！
    
    """
    
    a = 333333
    b = 333333.0
    print(id(a))
    print(id(b))
    
    print(a is b)
    print("***"*20)
    
    a = 3
    b = 3
    print(id(a))
    print(id(b))
    
    print(a is b)
    print("***"*20)
    
    a = "hello world"
    b = "HELLO WORLD"
    c = "hello "
    d = "hello world"
    print(id(a))
    print(id(b))
    print(id(c))
    print(id(d))
    
    print(a is b,a is c,b is c,a is d)
    
    '''
    输出结果：
    2039213240016
    2039234381168
    False
    ************************************************************
    1784504544
    1784504544
    True
    ************************************************************
    2039217328240
    2039217328176
    2039217247376
    2039217328240
    False False False True
    
    '''

## 四.**猜你喜欢** ##

1.  [Python 简介][Python 3]
2.  [Python Pycharm Anacanda 区别][Python Pycharm Anacanda]
3.  [Python2.x 和 Python3.x，如何选择？][Python2.x _ Python3.x]
4.  [Python 配置环境][Python 4]
5.  [Python Hello World 入门][Python Hello World]
6.  [Python 代码注释][Python 5]
7.  [Python 中文编码][Python 6]
8.  [Anaconda 是什么？Anconda 下载安装教程][Anaconda _Anconda]
9.  [Pycharm 提示：this license \*\*\*\* has been cancelled][Pycharm _this license _ has been cancelled]
10. [Pycharm 设置开发模板/字体大小/背景颜色][Pycharm]
11. [Python 列表 list][Python _ list]
12. [Python 元组 tuple][Python _ tuple]

未经允许不得转载：[猿说编程][Link 2] » [Python is 和 == 区别][Python is _ _]

[Python]: https://www.codersrc.com/python
[Python 1]: https://www.codersrc.com/pythonsimple
[is _ _]: https://www.codersrc.com/archives/5298.html
[Python 2]: https://www.codersrc.com/archives/5271.html
[Link 1]: https://www.codersrc.com/archives/4770.html
[Python 3]: https://www.codersrc.com/archives/4273.html
[Python Pycharm Anacanda]: https://www.codersrc.com/archives/4346.html
[Python2.x _ Python3.x]: https://www.codersrc.com/archives/4470.html
[Python 4]: https://www.codersrc.com/archives/4397.html
[Python Hello World]: https://www.codersrc.com/archives/4410.html
[Python 5]: https://www.codersrc.com/archives/4724.html
[Python 6]: https://www.codersrc.com/archives/4753.html
[Anaconda _Anconda]: https://www.codersrc.com/archives/4588.html
[Pycharm _this license _ has been cancelled]: https://www.codersrc.com/archives/4708.html
[Pycharm]: https://www.codersrc.com/archives/4735.html
[Python _ list]: https://www.codersrc.com/archives/5061.html
[Python _ tuple]: https://www.codersrc.com/archives/5088.html
[Link 2]: https://www.codersrc.com
[Python is _ _]: https://www.codersrc.com/archives/5288.html