Python Runtime Services
***********************

The modules described in this chapter provide a wide range of services
related to the Python interpreter and its interaction with its
environment.  Here's an overview:

* "sys" --- System-specific parameters and functions

* "sysconfig" --- Provide access to Python's configuration
  information

  * Configuration variables

  * Installation paths

  * Other functions

* "__builtin__" --- Built-in objects

* "future_builtins" --- Python 3 builtins

* "__main__" --- Top-level script environment

* "warnings" --- Warning control

  * Warning Categories

  * The Warnings Filter

    * Default Warning Filters

  * Temporarily Suppressing Warnings

  * Testing Warnings

  * Updating Code For New Versions of Python

  * Available Functions

  * Available Context Managers

* "contextlib" --- Utilities for "with"-statement contexts

* "abc" --- Abstract Base Classes

* "atexit" --- Exit handlers

  * "atexit" Example

* "traceback" --- Print or retrieve a stack traceback

  * Traceback Examples

* "__future__" --- Future statement definitions

* "gc" --- Garbage Collector interface

* "inspect" --- Inspect live objects

  * Types and members

  * Retrieving source code

  * Classes and functions

  * The interpreter stack

* "site" --- Site-specific configuration hook

* "user" --- User-specific configuration hook

* "fpectl" --- Floating point exception control

  * Example

  * Limitations and other considerations
