Update duplicate copies of pdb documentation with new prefix explanation

Lib/pdb.py

@@ -1638,13 +1638,17 @@ def do_help(self, arg):
     do_h = do_help
 
     def help_exec(self):
-        """(!) statement
+        """(!)statement
 
         Execute the (one-line) statement in the context of the current
         stack frame.  The exclamation point can be omitted unless the
-        first word of the statement resembles a debugger command.  To
-        assign to a global variable you must always prefix the command
-        with a 'global' command, e.g.:
+        first word of the statement resembles a debugger command, e.g.:
+        (Pdb) !next(some_iterator)
+        42
+        (Pdb)
+
+        To assign to a global variable you must always prefix the command with
+        a 'global' command, e.g.:
         (Pdb) global list_options; list_options = ['-l']
         (Pdb)
         """

Lib/pydoc_data/topics.py

@@ -5277,19 +5277,23 @@
              '\n'
              '   Delete the specified alias *name*.\n'
              '\n'
-             '! statement\n'
+             '!statement\n'
              '\n'
              '   Execute the (one-line) *statement* in the context of the '
              'current\n'
              '   stack frame. The exclamation point can be omitted unless the '
              'first\n'
-             '   word of the statement resembles a debugger command.  To set '
-             'a\n'
-             '   global variable, you can prefix the assignment command with '
-             'a\n'
-             '   "global" statement on the same line, e.g.:\n'
+             '   word of the statement resembles a debugger command, e.g.:'
+             '\n'
+             '      (Pdb) !next(some_iterator)\n'
+             '      42\n'
+             '      (Pdb)\n'
+             '\n'
+             'To set a global variable, you can prefix the assignment command '
+             'with \n'
+             'a "global" statement on the same line, e.g.:\n'
              '\n'
-             "      (Pdb) global list_options; list_options = ['-l']\n"
+             '      (Pdb) global list_options; list_options = ['-l']\n'
              '      (Pdb)\n'
              '\n'
              'run [args ...]\n'