fix: wrong placeholder in format string

pprett · pprett · commit 4e4a8a96810b · 2014-01-08T14:04:27.000+01:00
diff --git a/sklearn/tree/tree.py b/sklearn/tree/tree.py
@@ -213,7 +213,7 @@ def fit(self, X, y, sample_mask=None, X_argsorted=None, check_input=True,
             raise ValueError("max_leaf_nodes must be integral number but was "
                              "%r" % max_leaf_nodes)
         if -1 < max_leaf_nodes < 2:
-            raise ValueError(("max_leaf_nodes %r must be either smaller than 0 or "
+            raise ValueError(("max_leaf_nodes {0} must be either smaller than 0 or "
                              "larger than 1").format(max_leaf_nodes))
 
         if sample_weight is not None:
