fix exception type on None error

Cython/Compiler/ExprNodes.py

@@ -2839,7 +2839,8 @@ class SimpleCallNode(CallNode):
                 self_arg = func_type.args[0]
                 if self_arg.not_none: # C methods must do the None test for self at *call* time
                     self.self = self.self.as_none_safe_node(
-                        "'NoneType' object has no attribute '%s'" % self.function.entry.name)
+                        "'NoneType' object has no attribute '%s'" % self.function.entry.name,
+                        'PyExc_AttributeError')
                 expected_type = self_arg.type
                 self.coerced_self = CloneNode(self.self).coerce_to(
                     expected_type, env)

tests/run/set.pyx

@@ -60,7 +60,7 @@ def test_set_clear_None():
     """
     >>> test_set_clear_None()
     Traceback (most recent call last):
-    TypeError: 'NoneType' object has no attribute 'clear'
+    AttributeError: 'NoneType' object has no attribute 'clear'
     """
     cdef set s1 = None
     s1.clear()