bpo-29546: Improve from-import error message with location (#103)

bpo-29546: Improve from-import error message with location

1 files changed, 13 insertions, 1 deletions

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index df678f1..ace1a46 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -85,6 +85,15 @@ class ImportTests(unittest.TestCase):
             from os import i_dont_exist
         self.assertEqual(cm.exception.name, 'os')
         self.assertEqual(cm.exception.path, os.__file__)
+        self.assertRegex(str(cm.exception), "cannot import name 'i_dont_exist' from 'os' \(.*/Lib/os.py\)")
+
+    def test_from_import_missing_attr_has_name_and_so_path(self):
+        import _opcode
+        with self.assertRaises(ImportError) as cm:
+            from _opcode import i_dont_exist
+        self.assertEqual(cm.exception.name, '_opcode')
+        self.assertEqual(cm.exception.path, _opcode.__file__)
+        self.assertRegex(str(cm.exception), "cannot import name 'i_dont_exist' from '_opcode' \(.*\.(so|dll)\)")
 
     def test_from_import_missing_attr_has_name(self):
         with self.assertRaises(ImportError) as cm:
@@ -365,9 +374,12 @@ class ImportTests(unittest.TestCase):
         module_name = 'test_from_import_AttributeError'
         self.addCleanup(unload, module_name)
         sys.modules[module_name] = AlwaysAttributeError()
-        with self.assertRaises(ImportError):
+        with self.assertRaises(ImportError) as cm:
             from test_from_import_AttributeError import does_not_exist
 
+        self.assertEqual(str(cm.exception),
+            "cannot import name 'does_not_exist' from '<unknown module name>' (unknown location)")
+
 
 @skip_if_dont_write_bytecode
 class FilePermissionTests(unittest.TestCase):