gh-160998: Render interactive examples as code blocks in pydoc HTML output

Lib/pydoc.py

@@ -723,12 +723,15 @@ def markup(self, text, escape=None, funcs={}, classes={}, methods={}):
         pattern = re.compile(r'\b((http|https|ftp)://\S+[\w/]|'
                                 r'RFC[- ]?(\d+)|'
                                 r'PEP[- ]?(\d+)|'
-                                r'(self\.)?(\w+))')
+                                r'(self\.)?(\w+))|'
+                                r'\n*^(?P<indent>[ ]*)>>>(?:[ ].*)?$'
+                                r'(?:\n(?P=indent)(?=.*\S).*)*\n*',
+                             re.MULTILINE)
         while match := pattern.search(text, here):
             start, end = match.span()
             results.append(escape(text[here:start]))
 
-            all, scheme, rfc, pep, selfdot, name = match.groups()
+            all, scheme, rfc, pep, selfdot, name, indent = match.groups()
             if scheme:
                 url = escape(all).replace('"', '&quot;')
                 results.append('<a href="%s">%s</a>' % (url, url))
@@ -738,6 +741,20 @@ def markup(self, text, escape=None, funcs={}, classes={}, methods={}):
             elif pep:
                 url = 'https://peps.python.org/pep-%04d/' % int(pep)
                 results.append('<a href="%s">%s</a>' % (url, escape(all)))
+            elif indent is not None:
+                lines = []
+                for line in match.group().strip('\n').split('\n'):
+                    line = line.removeprefix(indent)
+                    if prompt := re.match(r'(>>>|\.\.\.)(?: |$)', line):
+                        line = ('<span class="prompt">%s</span>'
+                                % escape(prompt.group())
+                                + self.markup(line[prompt.end():], escape,
+                                              funcs, classes, methods))
+                    else:
+                        line = self.markup(line, escape,
+                                           funcs, classes, methods)
+                    lines.append(line)
+                results.append('<pre class="repl">%s</pre>' % '\n'.join(lines))
             elif selfdot:
                 # Create a link for methods like 'self.method(...)'
                 # and use <strong> for attributes like 'self.attr'

Lib/pydoc_data/_pydoc.css

@@ -125,16 +125,26 @@ section section {
 .docstring {
     white-space: pre-wrap;
     margin: 0.3em 0;
+    max-width: 50em;
 }
 
-pre.topic, pre.keyword {
+pre.topic, pre.keyword, pre.repl {
     background-color: var(--block-background-color);
     border: 1px solid var(--block-border-color);
     border-radius: 3px;
     padding: 0.5em 0.8em;
     overflow-x: auto;
 }
 
+pre.repl {
+    font-size: inherit;
+    margin: 0.5em 0;
+}
+
+.prompt {
+    color: var(--muted-color);
+}
+
 /* Documented names (functions, methods, data) */
 
 dl.doc {

Lib/test/test_pydoc/test_pydoc.py

@@ -1966,6 +1966,29 @@ def a_fn_with_https_link():
             html
         )
 
+    @requires_docstrings
+    def test_html_for_repl_examples(self):
+        def a_fn_with_repl_example():
+            """Do something.
+
+            Example:
+
+                >>> a_fn_with_repl_example()
+                ... # comment
+                result
+            Done.
+            """
+            pass
+
+        html = pydoc.HTMLDoc().document(a_fn_with_repl_example)
+        self.assertIn(
+            'Example:<pre class="repl">'
+            '<span class="prompt">&gt;&gt;&gt; </span>a_fn_with_repl_example()\n'
+            '<span class="prompt">... </span># comment\n'
+            'result</pre>Done.',
+            html
+        )
+
     def test_module_none(self):
         # Issue #128772
         from test.test_pydoc import module_none

Misc/NEWS.d/next/Library/2026-10-31-12-47-48.gh-issue-160998.5EpsBx.rst

@@ -0,0 +1,2 @@
+Render interactive examples in docstrings as separate blocks in the HTML output
+of :mod:`pydoc`.