fix

Author: HyukjinKwon

python/pyspark/sql/tests/pandas/test_pandas_grouped_map.py

@@ -19,6 +19,7 @@
 import unittest
 import logging
 import os
+import copy
 
 from collections import OrderedDict
 from decimal import Decimal
@@ -289,17 +290,19 @@ def stats_with_no_column_names(key, pdf):
         return pd.DataFrame([key + (pdf.v.mean(),)])
 
     def test_apply_in_pandas_returning_column_names(self):
-        self._test_apply_in_pandas(ApplyInPandasTestsMixin.stats_with_column_names)
+        self._test_apply_in_pandas(copy.deepcopy(ApplyInPandasTestsMixin.stats_with_column_names))
 
     def test_apply_in_pandas_returning_no_column_names(self):
-        self._test_apply_in_pandas(ApplyInPandasTestsMixin.stats_with_no_column_names)
+        self._test_apply_in_pandas(copy.deepcopy(ApplyInPandasTestsMixin.stats_with_no_column_names))
 
     def test_apply_in_pandas_returning_column_names_sometimes(self):
+        f = copy.deepcopy(ApplyInPandasTestsMixin.stats_with_column_names)
+
         def stats(key, pdf):
             if key[0] % 2:
-                return ApplyInPandasTestsMixin.stats_with_column_names(key, pdf)
+                return f(key, pdf)
             else:
-                return ApplyInPandasTestsMixin.stats_with_no_column_names(key, pdf)
+                return f(key, pdf)
 
         self._test_apply_in_pandas(stats)
 
@@ -869,10 +872,11 @@ def _test_apply_in_pandas(self, f, output_schema="id long, mean double"):
     def _test_apply_in_pandas_returning_empty_dataframe(self, empty_df):
         """Tests some returned DataFrames are empty."""
         df = self.data
+        f = copy.deepcopy(ApplyInPandasTestsMixin.stats_with_no_column_names)
 
         def stats(key, pdf):
             if key[0] % 2 == 0:
-                return ApplyInPandasTestsMixin.stats_with_no_column_names(key, pdf)
+                return f(key, pdf)
             return empty_df
 
         result = (