Closes #16110: fileConfig now accepts a pre-initialised ConfigParser instance.
diff --git a/Doc/library/logging.config.rst b/Doc/library/logging.config.rst
index d116d0a..16d3294 100644
--- a/Doc/library/logging.config.rst
+++ b/Doc/library/logging.config.rst
@@ -76,11 +76,23 @@
.. function:: fileConfig(fname, defaults=None, disable_existing_loggers=True)
- Reads the logging configuration from a :mod:`configparser`\-format file
- named *fname*. This function can be called several times from an
- application, allowing an end user to select from various pre-canned
- configurations (if the developer provides a mechanism to present the choices
- and load the chosen configuration).
+ Reads the logging configuration from a :mod:`configparser`\-format file.
+ This function can be called several times from an application, allowing an
+ end user to select from various pre-canned configurations (if the developer
+ provides a mechanism to present the choices and load the chosen
+ configuration).
+
+ :param fname: A filename, or a file-like object, or an instance derived
+ from :class:`~configparser.RawConfigParser`. If a
+ ``RawConfigParser``-derived instance is passed, it is used as
+ is. Otherwise, a :class:`~configparser.Configparser` is
+ instantiated, and the configuration read by it from the
+ object passed in ``fname``. If that has a :meth:`readline`
+ method, it is assumed to be a file-like object and read using
+ :meth:`~configparser.ConfigParser.read_file`; otherwise,
+ it is assumed to be a filename and passed to
+ :meth:`~configparser.ConfigParser.read`.
+
:param defaults: Defaults to be passed to the ConfigParser can be specified
in this argument.
@@ -94,6 +106,15 @@
their ancestors are explicitly named in the
logging configuration.
+ .. versionchanged:: 3.4
+ An instance of a subclass of :class:`~configparser.RawConfigParser` is
+ now accepted as a value for ``fname``. This facilitates:
+
+ * Use of a configuration file where logging configuration is just part
+ of the overall application configuration.
+ * Use of a configuration read from a file, and then modified by the using
+ application (e.g. based on command-line parameters or other aspects
+ of the runtime environment) before being passed to ``fileConfig``.
.. function:: listen(port=DEFAULT_LOGGING_CONFIG_PORT, verify=None)