April 2023
Intermediate to advanced
769 pages
25h 16m
Chinese
Content preview from 流畅的Python（第2版）
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332
第 13章
接口、协议和抽象基类
对接口编程，而不是对实现编程。
——
Gamma
、
Helm
、
Johnson
和
Vlissides
面向对象设计第一原则
1
面向对象编程全靠接口。如
8.4
节所述，在
Python
中，支撑一个类型的是它提供的方法，
也就是接口。
在不同的编程语言中，接口的定义和使用方式不尽相同。从
Python 3.8
开始，有
4
种方式，
如图
13-1
中的
类型图
所示。这
4
种方式概述如下。
鸭子类型
自
Python
诞生以来默认使用的类型实现方式。从第
1
章开始，本书一直在研究鸭子类型。
大鹅类型
自
Python 2.6
开始
，由抽象基类支持的方式，该方式会在运行时检查对象是否符合抽象
基类的要求。大鹅类型是本章的主要话题。
静态类型
C
和
Java
等传
统静态类型语言采用的方式。自
Python 3.5
开始，由
typing
模块支持，
由符合“
PEP
484
—
Type Hints
”要求的外部类型检查工具实施检查。本章不涉及该方
式。第
8
章的大多数内容和第
15
章讨论了静态类型。
静态鸭子类型
因
Go
语
言而流行的方式。由
typing.Protocol
（
Python 3.8
新增）的子类支持，由外部
类型检查工具实施检查。静态鸭子类型首次出现在
8.5.10
节。
注
1
：
出自《设计模式》“引言”部分。
接口、协议和抽象基类
｜
333 ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.