python - os.path 如何映射到 posixpath.pyc 而不是 os/path.py？

Question

Python中处理这种“别名”的底层机制是什么？

>>> import os.path
>>> os.path.__file__
'/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/posixpath.pyc'

Answer 1

取自 CPython 2.6 上的 os.py：

sys.modules['os.path'] = path
from os.path import (curdir, pardir, sep, pathsep, defpath, extsep, altsep,
    devnull)

path之前定义为平台特定模块：

if 'posix' in _names:
    name = 'posix'
    linesep = '\n'
    from posix import *
    try:
        from posix import _exit
    except ImportError:
        pass
    import posixpath as path

    import posix
    __all__.extend(_get_exports_list(posix))
    del posix

elif 'nt' in _names:
# ...

Answer 2

也许 os 使用 import as ？

import posixpath as path