Issue #18342: Use the repr of a module name for ``from ... import

...`` when an ImportError occurs.

Other cases had already been switched over to using the repr.

Thanks to Tomasz Maćkowiak for the patch.

Author: brettcannon

Lib/test/test_import.py

@@ -321,6 +321,14 @@ def test_delete_builtins_import(self):
         stdout, stderr = popen.communicate()
         self.assertIn(b"ImportError", stdout)
 
+    def test_from_import_message_for_nonexistent_module(self):
+        with self.assertRaisesRegexp(ImportError, "^No module named 'bogus'"):
+            from bogus import foo
+
+    def test_from_import_message_for_existing_module(self):
+        with self.assertRaisesRegexp(ImportError, "^cannot import name 'bogus'"):
+            from re import bogus
+
 
 @skip_if_dont_write_bytecode
 class FilePermissionTests(unittest.TestCase):

Misc/ACKS

@@ -786,6 +786,7 @@ Andrew I MacIntyre
 Tim MacKenzie
 Nick Maclaren
 Don MacMillen
+Tomasz Maćkowiak
 Steve Majewski
 Grzegorz Makarewicz
 David Malcolm

Misc/NEWS

@@ -10,6 +10,9 @@ What's New in Python 3.4.0 Alpha 1?
 Core and Builtins
 -----------------
 
+- Issue #18342: Use the repr of a module name when an import fails when using
+  ``from ... import ...``.
+
 - Issue #17872: Fix a segfault in marshal.load() when input stream returns
   more bytes than requested.
 

Python/ceval.c

@@ -4602,7 +4602,7 @@ import_from(PyObject *v, PyObject *name)
 
     x = PyObject_GetAttr(v, name);
     if (x == NULL && PyErr_ExceptionMatches(PyExc_AttributeError)) {
-        PyErr_Format(PyExc_ImportError, "cannot import name %S", name);
+        PyErr_Format(PyExc_ImportError, "cannot import name %R", name);
     }
     return x;
 }