python - from … import …

Posted 2020-10-16 blitheG

from . import XXX        默认的就是在当前程序所在文件夹里__init__.py程序中导入XXX

 

from .A import XXX     如果当前程序所在文件夹里没有__init__.py文件，导入A.py文件，A是指当前文件夹下你想导入的函数(或者其他的)的python程序名

 

如果你想导入的函数不在当前文件夹，那么就有可能用到 from .. import XXX(即上一个文件夹中的__init__.py)，或者from .. A import XXX(即上一个文件夹中的文件A)

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

　　You can also write relative imports, with the from module import name form of import statement. These imports use leading dots to indicate the current and parent packages involved in the relative import. From the surround module for example, you might use:

from . import echo
from .. import formats
from ..filters import equalizer