This module provides a more portable way of using operating
system dependent functionality than importing a operating system
dependent built-in module like posix or nt. This module searches
for an operating system dependent built-in module like mac or
posix and exports the same functions and data as found there.
The design of all Python's built-in operating system dependent
modules is such that as long as the same functionality is
available, it uses the same interface; for example, the function
os.stat(path) returns stat information about path in the same
format (which happens to have originated with the Extensions
peculiar to a particular operating system 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 operating system dependent built-in
module, so there should be no reason not to use os! The os
module contains many functions and