test_constructors.py 文件源码

def test_constructor_dict_cast(self):
        # cast float tests
        test_data = {
            'A': {'1': 1, '2': 2},
            'B': {'1': '1', '2': '2', '3': '3'},
        }
        frame = DataFrame(test_data, dtype=float)
        self.assertEqual(len(frame), 3)
        self.assertEqual(frame['B'].dtype, np.float64)
        self.assertEqual(frame['A'].dtype, np.float64)

        frame = DataFrame(test_data)
        self.assertEqual(len(frame), 3)
        self.assertEqual(frame['B'].dtype, np.object_)
        self.assertEqual(frame['A'].dtype, np.float64)

        # can't cast to float
        test_data = {
            'A': dict(zip(range(20), tm.makeStringIndex(20))),
            'B': dict(zip(range(15), randn(15)))
        }
        frame = DataFrame(test_data, dtype=float)
        self.assertEqual(len(frame), 20)
        self.assertEqual(frame['A'].dtype, np.object_)
        self.assertEqual(frame['B'].dtype, np.float64)