os
This module provides a more portable way of using operating system
(OS) dependent functionality than importing an OS dependent built-in
module like posix.
When the optional built-in module posix is available, this
module exports the same functions and data as posix; otherwise,
it searches for an OS dependent built-in module like mac and
exports the same functions and data as found there. The design of all
Python's built-in OS dependen modules is such that as long as the same
functionality is available, it uses the same interface; e.g., the
function os.stat(file) returns stat info about a file in a
format compatible with the POSIX interface.
Extensions peculiar to a particular OS are also available through the
os module, but using them is of course a threat to portability!
Note that after the first time os is imported, there is no
performance penalty in using functions from os instead of
directly from the OS dependent built-in module, so there should be
no reason not to use os!
In addition to whatever the correct OS dependent module exports, the
following variables and functions are always exported by os: