From 7099af8f5e6966bc0179b74c8306506d892282e7 Mon Sep 17 00:00:00 2001 From: Frost Ming Date: Mon, 8 Dec 2025 12:08:06 +0800 Subject: [PATCH] gh-139946: distinguish stdout or stderr when colorizing output in argparse (#140495) Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com> Co-authored-by: Savannah Ostrowski --- Lib/argparse.py | 44 +++++++++++++------ Lib/test/test_argparse.py | 34 ++++++++++++++ ...-10-23-06-38-35.gh-issue-139946.HZa5hu.rst | 1 + 3 files changed, 65 insertions(+), 14 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2025-10-23-06-38-35.gh-issue-139946.HZa5hu.rst diff --git a/Lib/argparse.py b/Lib/argparse.py index 398825508f59..1d550264ae42 100644 --- a/Lib/argparse.py +++ b/Lib/argparse.py @@ -89,8 +89,8 @@ __all__ = [ import os as _os import re as _re import sys as _sys - -from gettext import gettext as _, ngettext +from gettext import gettext as _ +from gettext import ngettext SUPPRESS = '==SUPPRESS==' @@ -191,10 +191,10 @@ class HelpFormatter(object): self._set_color(False) - def _set_color(self, color): + def _set_color(self, color, *, file=None): from _colorize import can_colorize, decolor, get_theme - if color and can_colorize(): + if color and can_colorize(file=file): self._theme = get_theme(force_color=True).argparse self._decolor = decolor else: @@ -1675,7 +1675,7 @@ class _ActionsContainer(object): option_strings = [] for option_string in args: # error on strings that don't start with an appropriate prefix - if not option_string[0] in self.prefix_chars: + if option_string[0] not in self.prefix_chars: raise ValueError( f'invalid option string {option_string!r}: ' f'must start with a character {self.prefix_chars!r}') @@ -2455,7 +2455,7 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer): return None # if it doesn't start with a prefix, it was meant to be positional - if not arg_string[0] in self.prefix_chars: + if arg_string[0] not in self.prefix_chars: return None # if the option string is present in the parser, return the action @@ -2717,14 +2717,16 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer): # Help-formatting methods # ======================= - def format_usage(self): - formatter = self._get_formatter() + def format_usage(self, formatter=None): + if formatter is None: + formatter = self._get_formatter() formatter.add_usage(self.usage, self._actions, self._mutually_exclusive_groups) return formatter.format_help() - def format_help(self): - formatter = self._get_formatter() + def format_help(self, formatter=None): + if formatter is None: + formatter = self._get_formatter() # usage formatter.add_usage(self.usage, self._actions, @@ -2746,9 +2748,9 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer): # determine help from format above return formatter.format_help() - def _get_formatter(self): + def _get_formatter(self, file=None): formatter = self.formatter_class(prog=self.prog) - formatter._set_color(self.color) + formatter._set_color(self.color, file=file) return formatter def _get_validation_formatter(self): @@ -2765,12 +2767,26 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer): def print_usage(self, file=None): if file is None: file = _sys.stdout - self._print_message(self.format_usage(), file) + formatter = self._get_formatter(file=file) + try: + usage_text = self.format_usage(formatter=formatter) + except TypeError: + # Backward compatibility for formatter classes that + # do not accept the 'formatter' keyword argument. + usage_text = self.format_usage() + self._print_message(usage_text, file) def print_help(self, file=None): if file is None: file = _sys.stdout - self._print_message(self.format_help(), file) + formatter = self._get_formatter(file=file) + try: + help_text = self.format_help(formatter=formatter) + except TypeError: + # Backward compatibility for formatter classes that + # do not accept the 'formatter' keyword argument. + help_text = self.format_help() + self._print_message(help_text, file) def _print_message(self, message, file=None): if message: diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py index 7c5eed21219d..ab5382e41e78 100644 --- a/Lib/test/test_argparse.py +++ b/Lib/test/test_argparse.py @@ -7558,6 +7558,40 @@ class TestColorized(TestCase): self.assertNotIn('\x1b[', warn) self.assertIn('warning:', warn) + def test_print_help_uses_target_file_for_color_decision(self): + parser = argparse.ArgumentParser(prog='PROG', color=True) + parser.add_argument('--opt') + output = io.StringIO() + calls = [] + + def fake_can_colorize(*, file=None): + calls.append(file) + return file is None + + with swap_attr(_colorize, 'can_colorize', fake_can_colorize): + parser.print_help(file=output) + + self.assertIs(calls[-1], output) + self.assertIn(output, calls) + self.assertNotIn('\x1b[', output.getvalue()) + + def test_print_usage_uses_target_file_for_color_decision(self): + parser = argparse.ArgumentParser(prog='PROG', color=True) + parser.add_argument('--opt') + output = io.StringIO() + calls = [] + + def fake_can_colorize(*, file=None): + calls.append(file) + return file is None + + with swap_attr(_colorize, 'can_colorize', fake_can_colorize): + parser.print_usage(file=output) + + self.assertIs(calls[-1], output) + self.assertIn(output, calls) + self.assertNotIn('\x1b[', output.getvalue()) + class TestModule(unittest.TestCase): def test_deprecated__version__(self): diff --git a/Misc/NEWS.d/next/Library/2025-10-23-06-38-35.gh-issue-139946.HZa5hu.rst b/Misc/NEWS.d/next/Library/2025-10-23-06-38-35.gh-issue-139946.HZa5hu.rst new file mode 100644 index 000000000000..fb4793172841 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2025-10-23-06-38-35.gh-issue-139946.HZa5hu.rst @@ -0,0 +1 @@ +Distinguish stdout and stderr when colorizing output in argparse module. -- 2.47.3