Avoid exiting the new REPL when there are non-string candidates for suggestions.

Author: devdanzin

Lib/_pyrepl/console.py

@@ -169,11 +169,14 @@ def showsyntaxerror(self, filename=None, **kwargs):
 
     def _excepthook(self, typ, value, tb):
         import traceback
-        lines = traceback.format_exception(
-                typ, value, tb,
-                colorize=self.can_colorize,
-                limit=traceback.BUILTIN_EXCEPTION_LIMIT)
-        self.write(''.join(lines))
+        try:
+            lines = traceback.format_exception(
+                    typ, value, tb,
+                    colorize=self.can_colorize,
+                    limit=traceback.BUILTIN_EXCEPTION_LIMIT)
+            self.write(''.join(lines))
+        except TypeError as e:
+            self.write(repr(e) + '\n')
 
     def runcode(self, code):
         try:

Lib/test/test_pyrepl/test_pyrepl.py

@@ -1318,6 +1318,15 @@ def test_null_byte(self):
         self.assertEqual(exit_code, 0)
         self.assertNotIn("TypeError", output)
 
+    def test_non_string_suggestion_candidates(self):
+        commands = ("import runpy\n"
+                    "runpy._run_module_code('blech', {0: '', 'bluch': ''}, '')\n"
+                    "exit()\n")
+
+        output, exit_code = self.run_repl(commands)
+        self.assertEqual(exit_code, 0)
+        self.assertIn("all elements in 'candidates' must be strings", output)
+
     def test_readline_history_file(self):
         # skip, if readline module is not available
         readline = import_module('readline')