[SPARK-10027] [ML] [PySpark] Add Python API missing methods for ml.feature

Missing method of ml.feature are listed here:
```StringIndexer``` lacks of parameter ```handleInvalid```.
```StringIndexerModel``` lacks of method ```labels```.
```VectorIndexerModel``` lacks of methods ```numFeatures``` and ```categoryMaps```.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #8313 from yanboliang/spark-10027.

1 files changed, 26 insertions, 5 deletions

diff --git a/python/pyspark/ml/feature.py b/python/pyspark/ml/feature.py
index 1c423486be..71dc636b83 100644
--- a/python/pyspark/ml/feature.py
+++ b/python/pyspark/ml/feature.py
@@ -920,7 +920,7 @@ class StandardScalerModel(JavaModel):
 
 
 @inherit_doc
-class StringIndexer(JavaEstimator, HasInputCol, HasOutputCol):
+class StringIndexer(JavaEstimator, HasInputCol, HasOutputCol, HasHandleInvalid):
     """
     .. note:: Experimental
 
@@ -943,19 +943,20 @@ class StringIndexer(JavaEstimator, HasInputCol, HasOutputCol):
     """
 
     @keyword_only
-    def __init__(self, inputCol=None, outputCol=None):
+    def __init__(self, inputCol=None, outputCol=None, handleInvalid="error"):
         """
-        __init__(self, inputCol=None, outputCol=None)
+        __init__(self, inputCol=None, outputCol=None, handleInvalid="error")
         """
         super(StringIndexer, self).__init__()
         self._java_obj = self._new_java_obj("org.apache.spark.ml.feature.StringIndexer", self.uid)
+        self._setDefault(handleInvalid="error")
         kwargs = self.__init__._input_kwargs
         self.setParams(**kwargs)
 
     @keyword_only
-    def setParams(self, inputCol=None, outputCol=None):
+    def setParams(self, inputCol=None, outputCol=None, handleInvalid="error"):
         """
-        setParams(self, inputCol=None, outputCol=None)
+        setParams(self, inputCol=None, outputCol=None, handleInvalid="error")
         Sets params for this StringIndexer.
         """
         kwargs = self.setParams._input_kwargs
@@ -1235,6 +1236,10 @@ class VectorIndexer(JavaEstimator, HasInputCol, HasOutputCol):
     >>> model = indexer.fit(df)
     >>> model.transform(df).head().indexed
     DenseVector([1.0, 0.0])
+    >>> model.numFeatures
+    2
+    >>> model.categoryMaps
+    {0: {0.0: 0, -1.0: 1}}
     >>> indexer.setParams(outputCol="test").fit(df).transform(df).collect()[1].test
     DenseVector([0.0, 1.0])
     >>> params = {indexer.maxCategories: 3, indexer.outputCol: "vector"}
@@ -1297,6 +1302,22 @@ class VectorIndexerModel(JavaModel):
     Model fitted by VectorIndexer.
     """
 
+    @property
+    def numFeatures(self):
+        """
+        Number of features, i.e., length of Vectors which this transforms.
+        """
+        return self._call_java("numFeatures")
+
+    @property
+    def categoryMaps(self):
+        """
+        Feature value index.  Keys are categorical feature indices (column indices).
+        Values are maps from original features values to 0-based category indices.
+        If a feature is not in this map, it is treated as continuous.
+        """
+        return self._call_java("javaCategoryMaps")
+
 
 @inherit_doc
 class VectorSlicer(JavaTransformer, HasInputCol, HasOutputCol):