Python: Essential Reference, Third Edition

select

The select module provides access to the select() and poll() system calls. select() is typically used to implement polling or to multiplex processing across multiple input/output streams without using threads or subprocesses. On UNIX, it works for files, sockets, pipes, and most other file types. On Windows, it only works for sockets.

						select(iwtd, owtd, ewtd
						[,
						timeout])

Queries the input, output, and exceptional status of a group of file descriptors. The first three arguments are lists containing either integer file descriptors or objects with a method, fileno(), that can be used to return a file descriptor. The iwtd parameter specifies objects waiting for input, owtd specifies objects waiting for output, and ewtd specifies objects waiting ...