fix the max_cardinality issue

Lilian Weng · Lilian Weng · commit 710b3e128f96 · 2016-12-16T10:49:04.000-08:00
diff --git a/sklearn/tree/_tree.pyx b/sklearn/tree/_tree.pyx
@@ -1192,7 +1192,7 @@ cdef class Tree:
     cdef np.ndarray _get_categorical_value_mapping(self):
         cdef SIZE_t i, node_id
         cdef SIZE_t cardinality
-        cdef SIZE_t max_cardinality = <SIZE_t> _TREE_UNDEFINED
+        cdef SIZE_t max_cardinality = 0
         cdef Node* node = NULL
 
         # Get max cardinality
@@ -1217,4 +1217,4 @@ cdef class Tree:
                 for i in range(node.categorical_cardinality):
                     mappings[node_id, i] = node.categorical_value_mapping[i]
 
-        return mappings
+        return mappings
diff --git a/sklearn/tree/tree.py b/sklearn/tree/tree.py
@@ -313,7 +313,7 @@ def fit(self, X, y, sample_weight=None, check_input=True,
                              ".shape = {})".format(X.shape,
                                                    X_idx_sorted.shape))
 
-        if categorical_features is not None:
+        if categorical_features:
             if max(categorical_features) >= self.n_features_:
                 raise ValueError("Categorical feature indices are out of the "
                                  "range; there are only {} features.".format(
