[py] split value histograms

tests/python/test_with_sklearn.py

@@ -240,3 +240,22 @@ def test_sklearn_nfolds_cv():
     cv3 = xgb.cv(params, dm, num_boost_round=10, nfold=nfolds, stratified=True, seed=seed)
     assert cv1.shape[0] == cv2.shape[0] and cv2.shape[0] == cv3.shape[0]
     assert cv2.iloc[-1, 0] == cv3.iloc[-1, 0]
+
+
+def test_split_value_histograms():
+    digits_2class = load_digits(2)
+
+    X = digits_2class['data']
+    y = digits_2class['target']
+
+    dm = xgb.DMatrix(X, label=y)
+    params = {'max_depth': 6, 'eta': 0.01, 'silent': 1, 'objective': 'binary:logistic'}
+
+    gbdt = xgb.train(params, dm, num_boost_round=10)
+    assert gbdt.get_split_value_histogram("not_there", as_pandas=True).shape[0] == 0
+    assert gbdt.get_split_value_histogram("not_there", as_pandas=False).shape[0] == 0
+    assert gbdt.get_split_value_histogram("f28", bins=0).shape[0] == 1
+    assert gbdt.get_split_value_histogram("f28", bins=1).shape[0] == 1
+    assert gbdt.get_split_value_histogram("f28", bins=2).shape[0] == 2
+    assert gbdt.get_split_value_histogram("f28", bins=5).shape[0] == 2
+    assert gbdt.get_split_value_histogram("f28", bins=None).shape[0] == 2