raise an AttributeError for six.moves.X when X is a module not available in the current interpreter

As discussed in https://github.com/pypa/pip/issues/1643.

3 files changed, 13 insertions, 2 deletions

diff --git a/CHANGES b/CHANGES
index 01c1e4a..140cae5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,12 @@ Changelog for six
 
 This file lists the changes in each six version.
 
+1.6.1
+-----
+
+- Raise an AttributeError for six.moves.X when X is a module not available in
+  the current interpreter.
+
 1.6.0
 -----
 
diff --git a/six.py b/six.py
index ad34014..6b6ad9f 100644
--- a/six.py
+++ b/six.py
@@ -83,7 +83,11 @@ class _LazyDescr(object):
         self.name = name
 
     def __get__(self, obj, tp):
-        result = self._resolve()
+        try:
+            result = self._resolve()
+        except ImportError:
+            # See the nice big comment in MovedModule.__getattr__.
+            raise AttributeError("%s could not be imported " % self.name)
         setattr(obj, self.name, result) # Invokes __set__.
         # This is a bit ugly, but it avoids running this again.
         delattr(obj.__class__, self.name)
diff --git a/test_six.py b/test_six.py
index 45649b2..47ad1ce 100644
--- a/test_six.py
+++ b/test_six.py
@@ -113,7 +113,8 @@ def test_move_items(item_name):
         if item_name.startswith("dbm_gnu") and not have_gdbm:
             py.test.skip("requires gdbm")
         raise
-    assert item_name in dir(six.moves)
+    if sys.version_info[:2] >= (2, 6):
+        assert item_name in dir(six.moves)
 
 
 @py.test.mark.parametrize("item_name",