gh-150285: Fix overflow in too long lines for class data in pydoc

Use all available space (80 columns) for formatting reprs
of module and class data, but ensure that they do not overflow.

Author: serhiy-storchaka

Lib/pydoc.py

@@ -1355,7 +1355,7 @@ def docmodule(self, object, name=None, mod=None, *ignored):
         if data:
             contents = []
             for key, value in data:
-                contents.append(self.docother(value, key, name, maxlen=70))
+                contents.append(self.docother(value, key, name, maxlen=76))
             result = result + self.section('DATA', '\n'.join(contents))
 
         if version := self._get_version(object):
@@ -1478,7 +1478,7 @@ def spilldata(msg, attrs, predicate):
                         obj = getattr(object, name)
                     except AttributeError:
                         obj = homecls.__dict__[name]
-                    push(self.docother(obj, name, mod, maxlen=70, doc=doc) +
+                    push(self.docother(obj, name, mod, maxlen=72, doc=doc) +
                          '\n')
             return attrs
 
@@ -1629,7 +1629,7 @@ def docother(self, object, name=None, mod=None, parent=None, *ignored,
         if maxlen:
             line = (name and name + ' = ' or '') + repr
             chop = maxlen - len(line)
-            if chop < 0: repr = repr[:chop] + '...'
+            if chop < 0: repr = repr[:chop-3] + '...'
         line = (name and self.bold(name) + ' = ' or '') + repr
         if not doc:
             doc = getdoc(object)

Misc/NEWS.d/next/Library/2026-06-11-19-46-16.gh-issue-150285.wuhAsL.rst

@@ -0,0 +1,2 @@
+:mod:`pydoc` now uses all available space (80 columns) for formatting reprs
+of module and class data, but ensure that they do not overflow.