[SPARK-11205][PYSPARK] Delegate to scala DataFrame API rather than p…

…rint in python

No test needed. Verify it manually in pyspark shell

Author: Jeff Zhang <[email protected]>

Closes #9177 from zjffdu/SPARK-11205.

Author: zjffdu

python/pyspark/sql/dataframe.py

@@ -212,6 +212,7 @@ def explain(self, extended=False):
         :param extended: boolean, default ``False``. If ``False``, prints only the physical plan.
 
         >>> df.explain()
+        == Physical Plan ==
         Scan PhysicalRDD[age#0,name#1]
 
         >>> df.explain(True)
@@ -227,7 +228,7 @@ def explain(self, extended=False):
         if extended:
             print(self._jdf.queryExecution().toString())
         else:
-            print(self._jdf.queryExecution().executedPlan().toString())
+            print(self._jdf.queryExecution().simpleString())
 
     @since(1.3)
     def isLocal(self):