gh-150285: Wrap long single-line summary in text output in pydoc

Lib/pydoc.py

@@ -1240,6 +1240,17 @@ def indent(self, text, prefix='    '):
         lines = [(prefix + line).rstrip() for line in text.split('\n')]
         return '\n'.join(lines)
 
+    def _format_doc(self, text, width=68):
+        """Wraps the single-line summary if it is too long."""
+        if not text: return ''
+        lines = text.split('\n', 2)
+        if len(lines) > 1 and lines[1]:
+            return text
+        lines[:1] = textwrap.wrap(lines[0], width,
+                                  break_long_words=False,
+                                  break_on_hyphens=False)
+        return '\n'.join(lines)
+
     def section(self, title, contents):
         """Format a section with a given heading."""
         clean_contents = self.indent(contents).rstrip()
@@ -1390,6 +1401,7 @@ def makename(c, m=object.__module__):
 
         doc = getdoc(object)
         if doc:
+            doc = self._format_doc(doc)
             push(doc + '\n')
 
         # List the mro, if non-trivial.
@@ -1590,6 +1602,7 @@ def docroutine(self, object, name=None, mod=None, cl=None, homecls=None):
             return decl + '\n'
         else:
             doc = getdoc(object) or ''
+            doc = self._format_doc(doc)
             return decl + '\n' + (doc and self.indent(doc).rstrip() + '\n')
 
     def docdata(self, object, name=None, mod=None, cl=None, *ignored):
@@ -1602,6 +1615,7 @@ def docdata(self, object, name=None, mod=None, cl=None, *ignored):
             push('\n')
         doc = getdoc(object) or ''
         if doc:
+            doc = self._format_doc(doc)
             push(self.indent(doc))
             push('\n')
         return ''.join(results)
@@ -1620,7 +1634,8 @@ def docother(self, object, name=None, mod=None, parent=None, *ignored,
         if not doc:
             doc = getdoc(object)
         if doc:
-            line += '\n' + self.indent(str(doc)) + '\n'
+            doc = self._format_doc(str(doc))
+            line += '\n' + self.indent(doc) + '\n'
         return line
 
 class _PlainTextDoc(TextDoc):

Misc/NEWS.d/next/Library/2026-06-08-15-04-35.gh-issue-150285.-Tj94n.rst

@@ -0,0 +1 @@
+:mod:`pydoc` now wraps long single-line summary in text output.