Cleanup pandas support

tests/python/test_basic.py

@@ -136,6 +136,51 @@ class TestBasic(unittest.TestCase):
         assert dm.num_row() == 2
         assert dm.num_col() == 3
 
+        df = pd.DataFrame({'A': ['X', 'Y', 'Z'], 'B': [1, 2, 3]})
+        dummies = pd.get_dummies(df)
+        #    B  A_X  A_Y  A_Z
+        # 0  1    1    0    0
+        # 1  2    0    1    0
+        # 2  3    0    0    1
+        result, _, _ = xgb.core._maybe_pandas_data(dummies, None, None)
+        exp = np.array([[ 1.,  1.,  0.,  0.],
+                        [ 2.,  0.,  1.,  0.],
+                        [ 3.,  0.,  0.,  1.]])
+        np.testing.assert_array_equal(result, exp)
+
+        dm = xgb.DMatrix(dummies)
+        assert dm.feature_names == ['B', 'A_X', 'A_Y', 'A_Z']
+        assert dm.feature_types == ['int', 'float', 'float', 'float']
+        assert dm.num_row() == 3
+        assert dm.num_col() == 4
+
+        df = pd.DataFrame({'A=1': [1, 2, 3], 'A=2': [4, 5, 6]})
+        dm = xgb.DMatrix(df)
+        assert dm.feature_names == ['A=1', 'A=2']
+        assert dm.feature_types == ['int', 'int']
+        assert dm.num_row() == 3
+        assert dm.num_col() == 2
+
+    def test_pandas_label(self):
+        import pandas as pd
+
+        # label must be a single column
+        df = pd.DataFrame({'A': ['X', 'Y', 'Z'], 'B': [1, 2, 3]})
+        self.assertRaises(ValueError, xgb.core._maybe_pandas_label, df)
+
+        # label must be supported dtype
+        df = pd.DataFrame({'A': np.array(['a', 'b', 'c'], dtype=object)})
+        self.assertRaises(ValueError, xgb.core._maybe_pandas_label, df)
+
+        df = pd.DataFrame({'A': np.array([1, 2, 3], dtype=int)})
+        result = xgb.core._maybe_pandas_label(df)
+        np.testing.assert_array_equal(result, np.array([[1.], [2.], [3.]], dtype=float))
+
+        dm = xgb.DMatrix(np.random.randn(3, 2), label=df)
+        assert dm.num_row() == 3
+        assert dm.num_col() == 2
+
+
     def test_load_file_invalid(self):
 
         self.assertRaises(ValueError, xgb.Booster,