python - __init__.py的作用是什么？(What is __init__.py for?)

Question

Python源目录中的__init__.py是什么？

  ask by Mat translate from so

Answer 1

It used to be a required part of a package ( old, pre-3.3 "regular package" , not newer 3.3+ "namespace package" ).

(它曾经是软件包的必需部分（ 旧的3.3之前的“常规软件包” ，而不是新的3.3+“命名空间软件包” ）。)

Here's the documentation.

(这是文档。)

Python defines two types of packages, regular packages and namespace packages.

(Python定义了两种类型的程序包，常规程序包和名称空间程序包。)

Regular packages are traditional packages as they existed in Python 3.2 and earlier.

(常规软件包是Python 3.2及更早版本中存在的传统软件包。)

A regular package is typically implemented as a directory containing an __init__.py file.

(常规软件包通常实现为包含__init__.py文件的目录。)

When a regular package is imported, this __init__.py file is implicitly executed, and the objects it defines are bound to names in the package's namespace.

(导入常规程序包时，将隐式执行此__init__.py文件，并将其定义的对象绑定到程序包名称空间中的名称。)

The __init__.py file can contain the same Python code that any other module can contain, and Python will add some additional attributes to the module when it is imported.

(__init__.py文件可以包含任何其他模块可以包含的相同Python代码，并且在导入时Python将向该模块添加一些其他属性。)

But just click the link, it contains an example, more information, and an explanation of namespace packages, the kind of packages without __init__.py .

(但是只需单击链接，它包含一个示例，更多信息以及名称空间包的说明，即不带__init__.py的包的类型。)