improve error message

qinhanmin2014 · qinhanmin2014 · commit 140287d59fcb · 2019-08-08T08:25:58.000+08:00
diff --git a/sklearn/metrics/_plot/roc_curve.py b/sklearn/metrics/_plot/roc_curve.py
@@ -146,7 +146,8 @@ def plot_roc_curve(estimator, X, y, pos_label=None, sample_weight=None,
 
     if y_pred.ndim != 1:
         if y_pred.shape[1] > 2:
-            raise ValueError("Estimator solve a binary classification problem")
+            raise ValueError("Estimator should solve a"
+                             "binary classification problem")
         y_pred = y_pred[:, 1]
     fpr, tpr, _ = roc_curve(y, y_pred, pos_label=pos_label,
                             drop_intermediate=drop_intermediate)
diff --git a/sklearn/metrics/_plot/tests/test_plot_roc_curve.py b/sklearn/metrics/_plot/tests/test_plot_roc_curve.py
@@ -25,7 +25,7 @@ def test_plot_roc_curve_error_non_binary(data):
     clf = DecisionTreeClassifier()
     clf.fit(X, y)
 
-    msg = "Estimator solve a binary classification problem"
+    msg = "Estimator should solve a binary classification problem"
     with pytest.raises(ValueError, match=msg):
         plot_roc_curve(clf, X, y)
 
