Module

[hug2wisdom]

Within a module, the module’s name (as a string) is available as the value of the global variable __name__. module.__name__ 表示模块的名字

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python fibo.py <arguments> 想要把模块当作脚本使用，则需要在模块内部最后添加

if __name__ == "__main__":
    import sys
    fib(int(sys.argv[1]))

这里只是举例。if __name__ == "__main__ 是必须的，you can make the file usable as a script as well as an importable module, because the code that parses the command line only runs if the module is executed as the “main” file。

主要运用场景：This is often used either to provide a convenient user interface to a module, or for testing purposes (running the module as a script executes a test suite).

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dir() Note that it lists all types of names: variables, modules, functions, etc.

[hug2wisdom]

Packages

eg:

sound/                          Top-level package
      __init__.py               Initialize the sound package
      formats/                  Subpackage for file format conversions
              __init__.py
              wavread.py
              wavwrite.py
              aiffread.py
              aiffwrite.py
              auread.py
              auwrite.py
              ...
      effects/                  Subpackage for sound effects
              __init__.py
              echo.py
              surround.py
              reverse.py
              ...
      filters/                  Subpackage for filters
              __init__.py
              equalizer.py
              vocoder.py
              karaoke.py
              ...

Note Contrarily, when using syntax like import item.subitem.subsubitem, each item except for the last must be a package; the last item can be a module or a package but can’t be a class or function or variable defined in the previous item. 最后一个元素不可以是类，函数或者变量。

if the package's init.py 里面有 all（'item1', 'item2', 'item3'），则可以使用：from sound.effects import * ，不然一般不建议使用。

[hug2wisdom]

每个模块都有一个name属性，当其值是'main'时，表明该模块自身在运行，否则是被引入。

说明：name 与 main 底下是双下划线， 是这样去掉中间的那个空格。