[SPARK-9828] [PYSPARK] Mutable values should not be default arguments

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #8110 from MechCoder/spark-9828.

1 files changed, 6 insertions, 2 deletions

diff --git a/python/pyspark/ml/tuning.py b/python/pyspark/ml/tuning.py
index 0bf988fd72..dcfee6a317 100644
--- a/python/pyspark/ml/tuning.py
+++ b/python/pyspark/ml/tuning.py
@@ -227,7 +227,9 @@ class CrossValidator(Estimator):
         bestModel = est.fit(dataset, epm[bestIndex])
         return CrossValidatorModel(bestModel)
 
-    def copy(self, extra={}):
+    def copy(self, extra=None):
+        if extra is None:
+            extra = dict()
         newCV = Params.copy(self, extra)
         if self.isSet(self.estimator):
             newCV.setEstimator(self.getEstimator().copy(extra))
@@ -250,7 +252,7 @@ class CrossValidatorModel(Model):
     def _transform(self, dataset):
         return self.bestModel.transform(dataset)
 
-    def copy(self, extra={}):
+    def copy(self, extra=None):
         """
         Creates a copy of this instance with a randomly generated uid
         and some extra params. This copies the underlying bestModel,
@@ -259,6 +261,8 @@ class CrossValidatorModel(Model):
         :param extra: Extra parameters to copy to the new instance
         :return: Copy of this instance
         """
+        if extra is None:
+            extra = dict()
         return CrossValidatorModel(self.bestModel.copy(extra))