Issue #5845: Enable tab-completion in the interactive interpreter by default, thanks to a new sys.__interactivehook__.

(original patch by Éric Araujo)

4 files changed, 44 insertions, 22 deletions

diff --git a/Doc/library/readline.rst b/Doc/library/readline.rst
index 1134619..692310b 100644
--- a/Doc/library/readline.rst
+++ b/Doc/library/readline.rst
@@ -190,28 +190,32 @@ Example
 
 The following example demonstrates how to use the :mod:`readline` module's
 history reading and writing functions to automatically load and save a history
-file named :file:`.pyhist` from the user's home directory.  The code below would
-normally be executed automatically during interactive sessions from the user's
-:envvar:`PYTHONSTARTUP` file. ::
+file named :file:`.python_history` from the user's home directory.  The code
+below would normally be executed automatically during interactive sessions
+from the user's :envvar:`PYTHONSTARTUP` file. ::
 
+   import atexit
    import os
    import readline
-   histfile = os.path.join(os.path.expanduser("~"), ".pyhist")
+
+   histfile = os.path.join(os.path.expanduser("~"), ".python_history")
    try:
        readline.read_history_file(histfile)
    except FileNotFoundError:
        pass
-   import atexit
+
    atexit.register(readline.write_history_file, histfile)
-   del os, histfile
+
+This code is actually automatically run when Python is run in
+:ref:`interactive mode <tut-interactive>` (see :ref:`rlcompleter-config`).
 
 The following example extends the :class:`code.InteractiveConsole` class to
 support history save/restore. ::
 
-   import code
-   import readline
    import atexit
+   import code
    import os
+   import readline
 
    class HistoryConsole(code.InteractiveConsole):
        def __init__(self, locals=None, filename="<console>",
diff --git a/Doc/library/rlcompleter.rst b/Doc/library/rlcompleter.rst
index 633088d..9ed01c7 100644
--- a/Doc/library/rlcompleter.rst
+++ b/Doc/library/rlcompleter.rst
@@ -27,18 +27,10 @@ Example::
    readline.__name__         readline.parse_and_bind(
    >>> readline.
 
-The :mod:`rlcompleter` module is designed for use with Python's interactive
-mode.  A user can add the following lines to his or her initialization file
-(identified by the :envvar:`PYTHONSTARTUP` environment variable) to get
-automatic :kbd:`Tab` completion::
-
-   try:
-       import readline
-   except ImportError:
-       print("Module readline not available.")
-   else:
-       import rlcompleter
-       readline.parse_and_bind("tab: complete")
+The :mod:`rlcompleter` module is designed for use with Python's
+:ref:`interactive mode <tut-interactive>`.  Unless Python is run with the
+:option:`-S` option, the module is automatically imported and configured
+(see :ref:`rlcompleter-config`).
 
 On platforms without :mod:`readline`, the :class:`Completer` class defined by
 this module can still be used for custom purposes.
diff --git a/Doc/library/site.rst b/Doc/library/site.rst
index 36b80c3..2175c3e 100644
--- a/Doc/library/site.rst
+++ b/Doc/library/site.rst
@@ -111,6 +111,23 @@ empty, and the path manipulations are skipped; however the import of
 :mod:`sitecustomize` and :mod:`usercustomize` is still attempted.
 
 
+.. _rlcompleter-config:
+
+Readline configuration
+----------------------
+
+On systems that support :mod:`readline`, this module will also import and
+configure the :mod:`rlcompleter` module, if Python is started in
+:ref:`interactive mode <tut-interactive>` and without the :option:`-S` option.
+The default behavior is enable tab-completion and to use
+:file:`~/.python_history` as the history save file.  To disable it, override
+the :data:`sys.__interactivehook__` attribute in your :mod:`sitecustomize`
+or :mod:`usercustomize` module or your :envvar:`PYTHONSTARTUP` file.
+
+
+Module contents
+---------------
+
 .. data:: PREFIXES
 
    A list of prefixes for site-packages directories.
@@ -153,8 +170,7 @@ empty, and the path manipulations are skipped; however the import of
 
    Adds all the standard site-specific directories to the module search
    path.  This function is called automatically when this module is imported,
-   unless the :program:`python` interpreter was started with the :option:`-S`
-   flag.
+   unless the Python interpreter was started with the :option:`-S` flag.
 
    .. versionchanged:: 3.3
       This function used to be called unconditionnally.
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 5f8399f..a405a30 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -679,6 +679,16 @@ always available.
    .. versionadded:: 3.1
 
 
+.. data:: __interactivehook__
+
+   When present, this function is automatically called (with no arguments)
+   when the interpreter is launched in :ref:`interactive mode <tut-interactive>`.
+   This is done after the :envvar:`PYTHONSTARTUP` file is read, so that you
+   can set this hook there.
+
+   .. versionadded:: 3.4
+
+
 .. function:: intern(string)
 
    Enter *string* in the table of "interned" strings and return the interned string