A unified interface for OS routines for Mac, NT, or Posix depending on what system we're on.
os.chdir(path) Change to another directory
os.getcwd() the complete path of the current working
directory
os.listdir() list of all files and directories in the
current directory
os.rename(src,dst) renames src to dst
os.remove(file) removes file
os.removedirs(path) a directory gets recursively removed
os.system(command) execute command in shell