This module provides access to the function select() available in most operating systems. Note that on Windows, it only works for sockets; on other operating systems, it also works for other file types (in particular, on Unix, it works on pipes). It cannot be used on regular files to determine whether a file has grown since it was last read.
The module defines the following:
The return value is a triple of lists of objects that are ready: subsets of the first three arguments. When the time-out is reached without a file descriptor becoming ready, three empty lists are returned.
Amongst the acceptable object types in the lists are Python file
objects (e.g. sys.stdin
, or objects returned by
open() or os.popen()), socket objects
returned by socket.socket(),