[SPARK-12090] [PYSPARK] consider shuffle in coalesce()

Author: Davies Liu <[email protected]>

Closes #10090 from davies/fix_coalesce.

(cherry picked from commit 4375eb3)
Signed-off-by: Davies Liu <[email protected]>

Author: Davies Liu

python/pyspark/rdd.py

@@ -2015,7 +2015,7 @@ def coalesce(self, numPartitions, shuffle=False):
         >>> sc.parallelize([1, 2, 3, 4, 5], 3).coalesce(1).glom().collect()
         [[1, 2, 3, 4, 5]]
         """
-        jrdd = self._jrdd.coalesce(numPartitions)
+        jrdd = self._jrdd.coalesce(numPartitions, shuffle)
         return RDD(jrdd, self.ctx, self._jrdd_deserializer)
 
     def zip(self, other):