
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
  * Using ``sysconfig`` as a script
* ``builtins`` --- Built-in objects
* ``__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
  * Utilities
  * Examples and Recipes
    * Supporting a variable number of context managers
    * Simplifying support for single optional context managers
    * Catching exceptions from ``__enter__`` methods
    * Cleaning up in an ``__enter__`` implementation
    * Replacing any use of ``try-finally`` and flag variables
    * Using a context manager as a function decorator
* ``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
  * Introspecting callables with the Signature object
  * Classes and functions
  * The interpreter stack
  * Fetching attributes statically
  * Current State of a Generator
* ``site`` --- Site-specific configuration hook
* ``fpectl`` --- Floating point exception control
  * Example
  * Limitations and other considerations
* ``distutils`` --- Building and installing Python modules