Fix column misalignment in help('topics') output

The 'help("topics")' output was misaligned due to "ASSIGNMENTEXPRESSIONS"
exceeding the implicit maximum default column width of 19 characters.

Reduced the number of columns from 4 to 3 in the listtopics()
function to allow more space for longer topic names.

Author: EtiennePelletier

Lib/pydoc.py

@@ -2083,7 +2083,7 @@ def intro(self):
 '''.format('%d.%d' % sys.version_info[:2]))
 
     def list(self, items, columns=4, width=80):
-        items = list(sorted(items))
+        items = sorted(items)
         colw = width / columns
         rows = (len(items) + columns - 1) / columns
         for row in range(rows):
@@ -2115,7 +2115,7 @@ def listtopics(self):
 Here is a list of available topics.  Enter any topic name to get more help.
 
 ''')
-        self.list(self.topics.keys())
+        self.list(self.topics.keys(), columns=3)
 
     def showtopic(self, topic, more_xrefs=''):
         try: