gh-125142: add REPL help text for keyboard shortcuts

Lib/pydoc.py

@@ -1797,6 +1797,55 @@ def writedocs(dir, pkgpath='', done=None):
         writedoc(modname)
     return
 
+
+def _intro_basic():
+    # Intro text if basic REPL is used.
+    ver = '%d.%d' % sys.version_info[:2]
+    return f'''\
+Welcome to Python {ver}'s help utility! If this is your first time using
+Python, you should definitely check out the tutorial at
+https://docs.python.org/{ver}/tutorial/.
+
+Enter the name of any module, keyword, or topic to get help on writing
+Python programs and using Python modules.  To get a list of available
+modules, keywords, symbols, or topics, enter "modules", "keywords",
+"symbols", or "topics".
+
+Each module also comes with a one-line summary of what it does; to list
+the modules whose name or summary contain a given string such as "spam",
+enter "modules spam".
+
+To quit this help utility and return to the interpreter,
+enter "q", "quit" or "exit".
+'''
+
+
+def _intro_pyrepl():
+    # Intro text if enhanced (non-basic) REPL is used.
+    ver = '%d.%d' % sys.version_info[:2]
+    return f'''
+Welcome to Python {ver}'s help utility! If this is your first time using
+Python, you should definitely check out the tutorial at
+https://docs.python.org/{ver}/tutorial/.
+
+You can use the following keyboard shortcuts at the main interpreter prompt.
+F1: enter interactive help, F2: enter history browsing mode, F3: enter paste
+mode (press again to exit).
+
+Enter the name of any module, keyword, or topic to get help on writing
+Python programs and using Python modules.  To get a list of available
+modules, keywords, symbols, or topics, enter "modules", "keywords",
+"symbols", or "topics".
+
+Each module also comes with a one-line summary of what it does; to list
+the modules whose name or summary contain a given string such as "spam",
+enter "modules spam".
+
+To quit this help utility and return to the interpreter,
+enter "q", "quit" or "exit".
+'''
+
+
 class Helper:
 
     # These dictionaries map a topic name to either an alias, or a tuple
@@ -2063,23 +2112,10 @@ def help(self, request, is_cli=False):
         self.output.write('\n')
 
     def intro(self):
-        self.output.write('''\
-Welcome to Python {0}'s help utility! If this is your first time using
-Python, you should definitely check out the tutorial at
-https://docs.python.org/{0}/tutorial/.
-
-Enter the name of any module, keyword, or topic to get help on writing
-Python programs and using Python modules.  To get a list of available
-modules, keywords, symbols, or topics, enter "modules", "keywords",
-"symbols", or "topics".
-
-Each module also comes with a one-line summary of what it does; to list
-the modules whose name or summary contain a given string such as "spam",
-enter "modules spam".
-
-To quit this help utility and return to the interpreter,
-enter "q", "quit" or "exit".
-'''.format('%d.%d' % sys.version_info[:2]))
+        if os.environ.get('PYTHON_BASIC_REPL'):
+            self.output.write(_intro_basic())
+        else:
+            self.output.write(_intro_pyrepl())
 
     def list(self, items, columns=4, width=80):
         items = list(sorted(items))

Misc/NEWS.d/next/Documentation/2024-10-08-10-44-14.gh-issue-125142.HVlHrs.rst

@@ -0,0 +1,2 @@
+As part of the builtin help intro text, show the keyboard shortcuts for the
+new, non-basic REPL (F1, F2, and F3).