| import unittest |
| from ctypes import * |
| |
| class StructFieldsTestCase(unittest.TestCase): |
| # Structure/Union classes must get 'finalized' sooner or |
| # later, when one of these things happen: |
| # |
| # 1. _fields_ is set. |
| # 2. An instance is created. |
| # 3. The type is used as field of another Structure/Union. |
| # 4. The type is subclassed |
| # |
| # When they are finalized, assigning _fields_ is no longer allowed. |
| |
| def test_1_A(self): |
| class X(Structure): |
| pass |
| self.assertEqual(sizeof(X), 0) # not finalized |
| X._fields_ = [] # finalized |
| self.assertRaises(AttributeError, setattr, X, "_fields_", []) |
| |
| def test_1_B(self): |
| class X(Structure): |
| _fields_ = [] # finalized |
| self.assertRaises(AttributeError, setattr, X, "_fields_", []) |
| |
| def test_2(self): |
| class X(Structure): |
| pass |
| X() |
| self.assertRaises(AttributeError, setattr, X, "_fields_", []) |
| |
| def test_3(self): |
| class X(Structure): |
| pass |
| class Y(Structure): |
| _fields_ = [("x", X)] # finalizes X |
| self.assertRaises(AttributeError, setattr, X, "_fields_", []) |
| |
| def test_4(self): |
| class X(Structure): |
| pass |
| class Y(X): |
| pass |
| self.assertRaises(AttributeError, setattr, X, "_fields_", []) |
| Y._fields_ = [] |
| self.assertRaises(AttributeError, setattr, X, "_fields_", []) |
| |
| if __name__ == "__main__": |
| unittest.main() |