I had the same problem as you, and then I made the following changes:
set PYSPARK_PYTHON as environment variable to point to python.exe in Edit Configurations of Pycharm, here is my example:
PYSPARK_PYTHON = D:\Anaconda3\python.exe
SPARK_HOME = D:\spark-1.6.3-bin-hadoop2.6
PYTHONUNBUFFERED = 1