3.14+ argparse colorization makes sub-commands prog always colored if colored at creation time

Bug report

Bug description:

Here's an example script that replicates the problem:

from __future__ import annotations

import os
from argparse import ArgumentParser
from contextlib import suppress
from unittest.mock import patch

os.environ["FORCE_COLOR"] = "1"

parser = ArgumentParser(description="argparse tester", prog="complex")
parser.add_argument("--root", action="store_true", help="root flag")
sub = parser.add_subparsers(dest="command")
sub.add_parser("demo")

with suppress(SystemExit):
    parser.parse_args(["demo", "--help"])

with patch.dict(os.environ, {"NO_COLOR": "1"}, clear=False):
    parser.parse_args(["demo", "--help"])

You can see the first invocation prints everything in color, while the second only the sub-command:

This is because https://github.com/python/cpython/blame/main/Lib/argparse.py#L1966 passes through the prog formatted and not as raw. This example is contrived a bit to have a minimal demonstration, the actual issue I'm facing is in https://github.com/tox-dev/sphinx-argparse-cli where I'm reading this value directly to generate Sphinx documentation from this.

CPython versions tested on:

3.14, 3.15

Operating systems tested on:

Linux, macOS

Linked PRs

As an aside, you can use parser = ArgumentParser(description="argparse tester", prog="complex", exit_on_error=False) to make testing easier.

>>> from argparse import ArgumentParser
>>> parser = ArgumentParser(description="argparse tester", prog="complex", exit_on_error=False)
>>> parser.parse_args(['dragons'])
Traceback (most recent call last):
  File "<python-input-2>", line 1, in <module>
    parser.parse_args(['dragons'])
    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
(snip...)
    raise ArgumentError(None, msg)
argparse.ArgumentError: unrecognized arguments: dragons
>>>

Hey - thanks for filing this. Looks like we missed applying _decolor here when we landed in #132323. I've opened a PR to fix this.

GH-139809: Fix argparse subcommand prog not respecting color environm…

pythonGH-139809: Fix argparse subcommand prog not respecting color en…

[3.14] GH-139809: Fix argparse subcommand prog not respecting color e…

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3.14+ argparse colorization makes sub-commands prog always colored if colored at creation time #139809

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Operating systems tested on:

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3.14+ argparse colorization makes sub-commands prog always colored if colored at creation time #139809

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Bug report

Bug description:

CPython versions tested on:

Operating systems tested on:

Linked PRs

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mpkocher commented on Oct 8, 2025

savannahostrowski commented on Oct 9, 2025

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