From: Berker Peksag <berker.peksag@gmail.com>
Date: Sun, 16 Oct 2016 22:05:04 +0000 (+0300)
Subject: Issue #21720: Improve exception message when the type of fromlist is unicode
X-Git-Tag: v2.7.13rc1~77
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=05b84439a3541ea3a2fdda9f8abfd46b64c431e8;p=python

Issue #21720: Improve exception message when the type of fromlist is unicode
---

diff --git a/Lib/test/test_import.py b/Lib/test/test_import.py
index 2abf5b2940..432500505e 100644
--- a/Lib/test/test_import.py
+++ b/Lib/test/test_import.py
@@ -415,6 +415,14 @@ class ImportTests(unittest.TestCase):
         finally:
             rmtree(dir_name)
 
+    def test_fromlist_type(self):
+        with self.assertRaises(TypeError) as cm:
+            __import__('encodings', fromlist=[u'aliases'])
+        self.assertIn('must be str, not unicode', str(cm.exception))
+        with self.assertRaises(TypeError) as cm:
+            __import__('encodings', fromlist=[1])
+        self.assertIn('must be str, not int', str(cm.exception))
+
 
 class PycRewritingTests(unittest.TestCase):
     # Test that the `co_filename` attribute on code objects always points
diff --git a/Misc/NEWS b/Misc/NEWS
index d0cc7a6c2a..ba5ad65970 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,11 @@ What's New in Python 2.7.13?
 Core and Builtins
 -----------------
 
+- Issue #21720: Improve exception message when the type of fromlist is unicode.
+  fromlist parameter of __import__() only accepts str in Python 2 and this
+  will help to identify the problem especially when the unicode_literals
+  future import is used.
+
 - Issue #26906: Resolving special methods of uninitialized type now causes
   implicit initialization of the type instead of a fail.
 
diff --git a/Python/import.c b/Python/import.c
index af47b0bdb4..1d74faf5f6 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -2591,8 +2591,9 @@ ensure_fromlist(PyObject *mod, PyObject *fromlist, char *buf, Py_ssize_t buflen,
             return 0;
         }
         if (!PyString_Check(item)) {
-            PyErr_SetString(PyExc_TypeError,
-                            "Item in ``from list'' not a string");
+            PyErr_Format(PyExc_TypeError,
+                         "Item in ``from list'' must be str, not %.200s",
+                         Py_TYPE(item)->tp_name);
             Py_DECREF(item);
             return 0;
         }