add new tests for stopwords

Author: burakkose

python/pyspark/ml/tests.py

@@ -336,13 +336,20 @@ def test_stopwordsremover(self):
         self.assertEqual(stopWordRemover.getInputCol(), "input")
         transformedDF = stopWordRemover.transform(dataset)
         self.assertEqual(transformedDF.head().output, ["panda"])
-        # Custom
+        # with particular stop words list
         stopwords = ["panda"]
         stopWordRemover.setStopWords(stopwords)
         self.assertEqual(stopWordRemover.getInputCol(), "input")
         self.assertEqual(stopWordRemover.getStopWords(), stopwords)
         transformedDF = stopWordRemover.transform(dataset)
         self.assertEqual(transformedDF.head().output, ["a"])
+        # with language selection
+        stopwords = StopWordsRemover.loadStopWords("turkish")
+        dataset = sqlContext.createDataFrame([Row(input=["acaba", "ama", "biri"])])
+        stopWordRemover.setStopWords(stopwords)
+        self.assertEqual(stopWordRemover.getStopWords(), stopwords)
+        transformedDF = stopWordRemover.transform(dataset)
+        self.assertEqual(transformedDF.head().output, [])
 
 
 class HasInducedError(Params):