Revert sys.ps1 and sys.ps2 after code interact

Author: gaogaotiantian

Lib/code.py

@@ -218,12 +218,14 @@ def interact(self, banner=None, exitmsg=None):
 
         """
         try:
-            sys.ps1
+            _ps1 = sys.ps1
         except AttributeError:
+            _ps1 = None
             sys.ps1 = ">>> "
         try:
-            sys.ps2
+            _ps2 = sys.ps2
         except AttributeError:
+            _ps2 = None
             sys.ps2 = "... "
         cprt = 'Type "help", "copyright", "credits" or "license" for more information.'
         if banner is None:
@@ -287,6 +289,12 @@ def interact(self, banner=None, exitmsg=None):
             if _quit is not None:
                 builtins.quit = _quit
 
+            if _ps1 is None:
+                del sys.ps1
+
+            if _ps2 is None:
+                del sys.ps2
+
             if exitmsg is None:
                 self.write('now exiting %s...\n' % self.__class__.__name__)
             elif exitmsg != '':

Lib/test/test_code_module.py

@@ -39,19 +39,47 @@ def setUp(self):
         self.mock_sys()
 
     def test_ps1(self):
-        self.infunc.side_effect = EOFError('Finished')
+        self.infunc.side_effect = [
+            "import code",
+            "code.sys.ps1",
+            EOFError('Finished')
+        ]
         self.console.interact()
-        self.assertEqual(self.sysmod.ps1, '>>> ')
+        output = ''.join(''.join(call[1]) for call in self.stdout.method_calls)
+        self.assertIn('>>> ', output)
+        self.assertFalse(hasattr(self.sysmod, 'ps1'))
+
+        self.infunc.side_effect = [
+            "import code",
+            "code.sys.ps1",
+            EOFError('Finished')
+        ]
         self.sysmod.ps1 = 'custom1> '
         self.console.interact()
+        output = ''.join(''.join(call[1]) for call in self.stdout.method_calls)
+        self.assertIn('custom1> ', output)
         self.assertEqual(self.sysmod.ps1, 'custom1> ')
 
     def test_ps2(self):
-        self.infunc.side_effect = EOFError('Finished')
+        self.infunc.side_effect = [
+            "import code",
+            "code.sys.ps2",
+            EOFError('Finished')
+        ]
         self.console.interact()
-        self.assertEqual(self.sysmod.ps2, '... ')
+        output = ''.join(''.join(call[1]) for call in self.stdout.method_calls)
+        self.assertIn('... ', output)
+        self.assertFalse(hasattr(self.sysmod, 'ps2'))
+
+        self.infunc.side_effect = [
+            "import code",
+            "code.sys.ps2",
+            EOFError('Finished')
+        ]
         self.sysmod.ps2 = 'custom2> '
         self.console.interact()
+        output = ''.join(''.join(call[1]) for call in self.stdout.method_calls)
+        self.assertIn('custom2> ', output)
         self.assertEqual(self.sysmod.ps2, 'custom2> ')
 
     def test_console_stderr(self):