[SPARK-7242] added python api for freqItems in DataFrames

The python api for DataFrame's plus addressed your comments from previous PR.
rxin

Author: Burak Yavuz <brkyvz@gmail.com>

Closes #5859 from brkyvz/df-freq-py2 and squashes the following commits:

f9aa9ce [Burak Yavuz] addressed comments v0.1
4b25056 [Burak Yavuz] added python api for freqItems

1 files changed, 7 insertions, 0 deletions

diff --git a/python/pyspark/sql/tests.py b/python/pyspark/sql/tests.py
index 44c8b6a1aa..613efc0ac0 100644
--- a/python/pyspark/sql/tests.py
+++ b/python/pyspark/sql/tests.py
@@ -375,6 +375,13 @@ class SQLTests(ReusedPySparkTestCase):
         self.assertEqual(self.testData, df.select(df.key, df.value).collect())
         self.assertEqual([Row(value='1')], df.where(df.key == 1).select(df.value).collect())
 
+    def test_freqItems(self):
+        vals = [Row(a=1, b=-2.0) if i % 2 == 0 else Row(a=i, b=i * 1.0) for i in range(100)]
+        df = self.sc.parallelize(vals).toDF()
+        items = df.stat.freqItems(("a", "b"), 0.4).collect()[0]
+        self.assertTrue(1 in items[0])
+        self.assertTrue(-2.0 in items[1])
+
     def test_aggregator(self):
         df = self.df
         g = df.groupBy()