[SPARK-13019] re-organize python import

Author: keypointt

examples/src/main/python/mllib/correlations_example.py

@@ -17,8 +17,9 @@
 
 from __future__ import print_function
 
-from pyspark import SparkContext
 import numpy as np
+
+from pyspark import SparkContext
 # $example on$
 from pyspark.mllib.stat import Statistics
 # $example off$

examples/src/main/python/mllib/hypothesis_testing_example.py

@@ -18,9 +18,7 @@
 from __future__ import print_function
 
 from pyspark import SparkContext
-from pyspark.mllib.linalg import Vectors
 # $example on$
-from pyspark import SparkContext
 from pyspark.mllib.linalg import Vectors, Matrices
 from pyspark.mllib.regression import LabeledPoint
 from pyspark.mllib.stat import Statistics

examples/src/main/python/mllib/summary_statistics_example.py

@@ -17,8 +17,9 @@
 
 from __future__ import print_function
 
-from pyspark import SparkContext
 import numpy as np
+
+from pyspark import SparkContext
 # $example on$
 from pyspark.mllib.stat import Statistics
 # $example off$