**Source code:** :source:`Lib/bisect.py`

This module provides support for maintaining a list in sorted order without

having to sort the list after each insertion. For long lists of items with

expensive comparison operations, this can be an improvement over the more common

**Source code:** :source:`Lib/calendar.py`

This module allows you to output calendars like the Unix :program:`cal` program,

and provides additional useful functions related to the calendar. By default,

these calendars have Monday as the first day of the week, and Sunday as the last

**Source code:** :source:`Lib/cmd.py`

The :class:`Cmd` class provides a simple framework for writing line-oriented

command interpreters. These are often useful for test harnesses, administrative

tools, and prototypes that will later be wrapped in a more sophisticated

**Source code:** :source:`Lib/collections.py`

This module implements specialized container datatypes providing alternatives to

Python's general purpose built-in containers, :class:`dict`, :class:`list`,

:class:`set`, and :class:`tuple`.

**Source code:** :source:`Lib/contextlib.py`

This module provides utilities for common tasks involving the :keyword:`with`

statement. For more information see also :ref:`typecontextmanager` and

:ref:`context-managers`.

**Source code:** :source:`Lib/dis.py`

The :mod:`dis` module supports the analysis of CPython :term:`bytecode` by

disassembling it. The CPython bytecode which this module takes as an

input is defined in the file :file:`Include/opcode.h` and used by the compiler

**Source code:** :source:`Lib/filecmp.py`

The :mod:`filecmp` module defines functions to compare files and directories,

with various optional time/correctness trade-offs. For comparing files,

see also the :mod:`difflib` module.

**Source code:** :source:`Lib/fileinput.py`

This module implements a helper class and functions to quickly write a

loop over standard input or a list of files. If you just want to read or

write one file see :func:`open`.

**Source code:** :source:`Lib/fnmatch.py`

This module provides support for Unix shell-style wildcards, which are *not* the

same as regular expressions (which are documented in the :mod:`re` module). The

special characters used in shell-style wildcards are: