Backport PR #2685: Fix pretty print of types when `__module__` is not available.

In Python 3, heap allocated types -- for example those created using
PyType_FromSpec -- lack the `__module__` attribute.

Closes  #2684

IPython/lib/pretty.py

@@ -602,10 +602,16 b' def _re_pattern_pprint(obj, p, cycle):'
 
 def _type_pprint(obj, p, cycle):
     """The pprint for classes and types."""
-    if obj.__module__ in ('__builtin__', 'exceptions'):
+    try:
+        mod = obj.__module__
+    except AttributeError:
+        # Heap allocated types might not have the module attribute.
+        return p.text(obj.__name__)
+
+    if mod in ('__builtin__', 'exceptions'):
         name = obj.__name__
     else:
-        name = obj.__module__ + '.' + obj.__name__
+        name = mod + '.' + obj.__name__
     p.text(name)
 
 

IPython/lib/tests/test_pretty.py

@@ -18,6 +18,7 b' import nose.tools as nt'
 
 # Our own imports
 from IPython.lib import pretty
+from IPython.testing.decorators import skip_without
 
 #-----------------------------------------------------------------------------
 # Classes and functions
@@ -63,3 +64,12 b' def test_dispatch():'
     expectedoutput = "MyDict(...)"
 
     nt.assert_equals(gotoutput, expectedoutput)
+
+@skip_without('xxlimited')
+def test_pprint_heap_allocated_type():
+    """
+    Test that pprint works for heap allocated types.
+    """
+    import xxlimited
+    output = pretty.pretty(xxlimited.Null)
+    nt.assert_equal(output, 'xxlimited.Null')