New REPL - readline module does not save history with write_history_file

[devcode11]

Bug report

Bug description:

When using new REPL in Python 13, the readline module does not write history to the files correctly.
I have checked this issue on both my host system, as well as python:alpine container from docker.

Using PYTHON_BASIC_REPL=1 no longer causes this issue.

Expected
hist.txt file contains the saved commands.

Actual
hist.txt file is empty. Note that .python_history file does save and load history correctly.

/ # python -i
Python 3.13.2 (main, Feb 14 2025, 19:28:41) [GCC 14.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import readline
>>> print('abc')
abc
>>> readline.get_current_history_length()
0
>>> readline.set_history_length(100)
>>> readline.get_current_history_length()
0
>>> readline.write_history_file('hist.txt')
>>> 
/ # cat hist.txt 
/ # cat ~/.python_history 
import readline
print('abc')
readline.get_current_history_length()
readline.set_history_length(100)
readline.get_current_history_length()
readline.write_history_file('hist.txt')
/ # 

CPython versions tested on:

3.13

Operating systems tested on:

Linux

[oedokumaci]

>>> readline.get_current_history_length()
0
>>> readline.set_history_length(100)
>>> readline.get_current_history_length()
0

set_history_length method sets the _ReadlineWrapper.saved_history_length attribute, which you can get by get_history_length not get_current_history_length

What is the readline version of your runtime? You can check by

import readline
readline._READLINE_LIBRARY_VERSION

[oedokumaci]

I digged a little further and It seems that when you do import readline despite CAN_USE_PYREPL flag being True it still imports the readline.c. The python implementation _pyrepl/readline.py is then never imported unless you reload the sys.modules. So the public api _wrapper = _ReadlineWrapper() of _pyrepl/readline.py is not being used.

If what I said is true and that it needs a fix, I can help if a core dev can point me in the right direction.

[ambv]

Closing as duplicate of #120766. We'll handle it.