add crosstab pyTest

Author: brkyvz

python/pyspark/sql/dataframe.py

@@ -899,17 +899,12 @@ def crosstab(self, col1, col2):
 
         :param col1: The name of the first column
         :param col2: The name of the second column
-        
-        >>> df3.crosstab("age", "height").show()
-        age_height 80 85
-        2 1 1
-        5 1 1
         """
         if not isinstance(col1, str):
             raise ValueError("col1 should be a string.")
         if not isinstance(col2, str):
             raise ValueError("col2 should be a string.")
-        return self._jdf.stat().crosstab(col1, col2)
+        return DataFrame(self._jdf.stat().crosstab(col1, col2), self.sql_ctx)
 
     @ignore_unicode_prefix
     def withColumn(self, colName, col):

python/pyspark/sql/tests.py

@@ -392,6 +392,14 @@ def test_cov(self):
         cov = df.stat.cov("a", "b")
         self.assertTrue(abs(cov - 55.0 / 3) < 1e-6)
 
+    def test_crosstab(self):
+        df = self.sc.parallelize([Row(a=i % 3, b=i % 2) for i in range(1, 7)]).toDF()
+        ct = df.stat.crosstab("a", "b")
+        for i, row in enumerate(ct.collect()):
+            self.assertEqual(row[0], str(i))
+            self.assertTrue(row[1], 1)
+            self.assertTrue(row[2], 1)
+
     def test_math_functions(self):
         df = self.sc.parallelize([Row(a=i, b=2 * i) for i in range(10)]).toDF()
         from pyspark.sql import mathfunctions as functions