| import unittest |
| from ctypes import * |
| |
| ################################################################ |
| # |
| # The incomplete pointer example from the tutorial |
| # |
| |
| class MyTestCase(unittest.TestCase): |
| |
| def test_incomplete_example(self): |
| lpcell = POINTER("cell") |
| class cell(Structure): |
| _fields_ = [("name", c_char_p), |
| ("next", lpcell)] |
| |
| SetPointerType(lpcell, cell) |
| |
| c1 = cell() |
| c1.name = "foo" |
| c2 = cell() |
| c2.name = "bar" |
| |
| c1.next = pointer(c2) |
| c2.next = pointer(c1) |
| |
| p = c1 |
| |
| result = [] |
| for i in range(8): |
| result.append(p.name) |
| p = p.next[0] |
| self.assertEqual(result, ["foo", "bar"] * 4) |
| |
| # to not leak references, we must clean _pointer_type_cache |
| from ctypes import _pointer_type_cache |
| del _pointer_type_cache[cell] |
| |
| ################################################################ |
| |
| if __name__ == '__main__': |
| unittest.main() |