1 import unittest 2 from ctypes import * 3 4 ################################################################ 5 # 6 # The incomplete pointer example from the tutorial 7 # 8 9 class MyTestCase(unittest.TestCase): 10 11 def test_incomplete_example(self): 12 lpcell = POINTER("cell") 13 class cell(Structure): 14 _fields_ = [("name", c_char_p), 15 ("next", lpcell)] 16 17 SetPointerType(lpcell, cell) 18 19 c1 = cell() 20 c1.name = "foo" 21 c2 = cell() 22 c2.name = "bar" 23 24 c1.next = pointer(c2) 25 c2.next = pointer(c1) 26 27 p = c1 28 29 result = [] 30 for i in range(8): 31 result.append(p.name) 32 p = p.next[0] 33 self.assertEqual(result, ["foo", "bar"] * 4) 34 35 # to not leak references, we must clean _pointer_type_cache 36 from ctypes import _pointer_type_cache 37 del _pointer_type_cache[cell] 38 39 ################################################################ 40 41 if __name__ == '__main__': 42 unittest.main() 43
