Pasting a function definition does not work in 3.13 REPL with Windows Terminal

[japageth]

Bug report

Bug description:

I use Python downloaded from python.org without using a graphical environment such as IPython. Instead, I use the Windows Terminal with the REPL built into python.exe. In 3.12.6, I can paste a function definition copied from a text editor directly into the REPL and everything works fine. In 3.13.rc2 this does not work; the indentation is all messed up and I get an IndentationError.

def letter_colors(word, guess):
    '''Compute letter colors for Wordle guesses.  B=black Y=yellow G=green'''
    if (n := len(word)) != len(guess):
        raise ValueError('Word and guess must be the same length.')
    result = ['G' if wl == gl else 'B' for (wl, gl) in zip(word, guess)]
    unused = [w for (w, r) in zip(word, result) if r == 'B']
    for i, c in enumerate(guess):
        if result[i] != 'G' and c in unused:
            result[i] = 'Y'
            unused.remove(c)
    return ''.join(result)

CPython versions tested on:

3.12, 3.13

Operating systems tested on:

Windows

Linked PRs

• gh-124096: Enable REPL virtual terminal support on Windows #124119

[terryjreedy]

The code you show looks fine to me. Is this what you see in 3.13?
Please copy and paste the full traceback or message.

[Wulian233]

The bug can be reproduced, here is a screenshot

Duplicate #122237
PR #122383

[terryjreedy]

Thank you for the additional clear info. Closing as duplicate.

[y5c4l3]

Duplicate #122237 PR #122383

This is not a duplicate. It's a Windows-specific issue that WinAPI requires a console application to set their input handle with ENABLE_VIRTUAL_TERMINAL_INPUT flag before it can be talked in VT escaped sequences. The flag isn't set in windows_console.py, so it's impossible to have bracketed-paste wrapping sequences sent to PYREPL.

Even if it is set, the default Windows command prompt, at least on 21H2 LTSC, does not support bracketed-paste. A modern terminal emulator like your Windows Terminal is required for this feature. We need to figure out a way to make an educated guess at user's terminal and turn off the autoindentation if necessary.

PYREPL is atm only scanning virtual key codes under Windows, once the console is configured as a virtual terminal, all the keys will be sent in VT sequences.

PR: #124119

[Wulian233]

oh, you are right
@terryjreedy We need reopen this

[MMateo1120]

I am using VS Code on Windows, and extra indentations are added when I shift+enter my code to run in the terminal. Also, even if I just copy the code into the terminal extra indentations are added. Any solution to the problem so far? The problem seems similar to microsoft/vscode-python#24256 where it was solved for some by the pre-lease version of python extension for vs code, but still exist for me on Windows.

Uninstalled every extension but python's:

I am using the pre-lease version:

the python version of 3.13.0 64-bit:

Started a new window, a brand new py file but after shift+enter, the same behaviour is found as before:

If i ctrl c ctrl v the code into the terminal, extra indents are added just by the copying of the code into the terminal:

[anthonykim1]

Adding to @MMateo1120 folks are also able to repro this outside of VS Code terminal (in external terminal) where indentations breaks like the image above.