Add colour to Python help

Author: hugovk

Doc/whatsnew/3.15.rst

@@ -512,6 +512,11 @@ Other language changes
 
   (Contributed by Adam Turner in :gh:`133711`; PEP 686 written by Inada Naoki.)
 
+* The interpreter help (such as ``python --help``) is now in color.
+  This can be controlled by :ref:`environment variables
+  <using-on-controlling-color>`.
+  (Contributed by Hugo van Kemenade in :gh:`148766`.)
+
 * Unraisable exceptions are now highlighted with color by default. This can be
   controlled by :ref:`environment variables <using-on-controlling-color>`.
   (Contributed by Peter Bierma in :gh:`134170`.)

Lib/test/test_cmd_line.py

@@ -57,6 +57,7 @@ def verify_valid_flag(self, cmd_line):
         return out
 
     @support.cpython_only
+    @support.force_not_colorized
     def test_help(self):
         self.verify_valid_flag('-h')
         self.verify_valid_flag('-?')
@@ -68,6 +69,7 @@ def test_help(self):
         self.assertLess(len(lines), 50)
 
     @support.cpython_only
+    @support.force_not_colorized
     def test_help_env(self):
         out = self.verify_valid_flag('--help-env')
         self.assertIn(b'PYTHONHOME', out)
@@ -81,6 +83,7 @@ def test_help_env(self):
                              "env vars should be sorted alphabetically")
 
     @support.cpython_only
+    @support.force_not_colorized
     def test_help_xoptions(self):
         out = self.verify_valid_flag('--help-xoptions')
         self.assertIn(b'-X dev', out)
@@ -89,6 +92,7 @@ def test_help_xoptions(self):
                          "options should be sorted alphabetically")
 
     @support.cpython_only
+    @support.force_not_colorized
     def test_help_all(self):
         out = self.verify_valid_flag('--help-all')
         lines = out.splitlines()
@@ -100,6 +104,25 @@ def test_help_all(self):
         # but the rest should be ASCII-only
         b''.join(lines[1:]).decode('ascii')
 
+    @support.cpython_only
+    @support.force_colorized
+    def test_help_colorized(self):
+        rc, out, err = assert_python_ok("--help", FORCE_COLOR="1")
+        # Check ANSI color codes are present
+        self.assertIn(b"\x1b[", out)
+        # Check that key text elements are still present
+        self.assertIn(b"usage:", out)
+        self.assertIn(b"-h", out)
+        self.assertIn(b"--help-all", out)
+        self.assertIn(b"cmd", out)
+        self.assertIn(b"Arguments:", out)
+
+    @support.cpython_only
+    @support.force_not_colorized
+    def test_help_not_colorized(self):
+        rc, out, err = assert_python_ok("--help")
+        self.assertNotIn(b"\x1b[", out)
+
     def test_optimize(self):
         self.verify_valid_flag('-O')
         self.verify_valid_flag('-OO')
@@ -1063,6 +1086,7 @@ def test_argv0_normalization(self):
         self.assertEqual(proc.stdout.strip(), b'0')
 
     @support.cpython_only
+    @support.force_not_colorized
     def test_parsing_error(self):
         args = [sys.executable, '-I', '--unknown-option']
         proc = subprocess.run(args,

Misc/NEWS.d/next/Core_and_Builtins/2026-04-19-22-35-39.gh-issue-148766.coLWln.rst

@@ -0,0 +1,2 @@
+The interpreter help (such as ``python --help``) is now in color. Patch by
+Hugo van Kemenade.