bpo-41525: Make the Python program help ASCII-only (GH-21836)

Lib/test/test_cmd_line.py

@@ -46,7 +46,11 @@ class CmdLineTest(unittest.TestCase):
 
     def test_usage(self):
         rc, out, err = assert_python_ok('-h')
-        self.assertIn(b'usage', out)
+        lines = out.splitlines()
+        self.assertIn(b'usage', lines[0])
+        # The first line contains the program name,
+        # but the rest should be ASCII-only
+        b''.join(lines[1:]).decode('ascii')
 
     def test_version(self):
         version = ('Python %d.%d' % sys.version_info[:2]).encode("ascii")

Misc/NEWS.d/next/Core and Builtins/2020-08-12-07-35-07.bpo-41525.d9q3XL.rst

@@ -0,0 +1 @@
+The output of ``python --help`` contains now only ASCII characters.

Misc/python.man

@@ -291,7 +291,7 @@ Set implementation specific option. The following options are available:
         nested imports). Note that its output may be broken in multi-threaded
         application. Typical usage is python3 -X importtime -c 'import asyncio'
 
-    -X dev: enable CPython’s “development mode”, introducing additional runtime
+    -X dev: enable CPython's "development mode", introducing additional runtime
         checks which are too expensive to be enabled by default. It will not be
         more verbose than the default if the code is correct: new warnings are
         only emitted when an issue is detected. Effect of the developer mode:

Python/initconfig.c

@@ -83,7 +83,7 @@ static const char usage_3[] = "\
              cumulative time (including nested imports) and self time (excluding\n\
              nested imports). Note that its output may be broken in multi-threaded\n\
              application. Typical usage is python3 -X importtime -c 'import asyncio'\n\
-         -X dev: enable CPython’s “development mode”, introducing additional runtime\n\
+         -X dev: enable CPython's \"development mode\", introducing additional runtime\n\
              checks which are too expensive to be enabled by default. Effect of the\n\
              developer mode:\n\
                 * Add default warning filter, as -W default\n\