KeyError：SARKCONF初始化期间的SkkkHOB

Question

我是一个spark新手，我想从命令行运行一个Python脚本。我已经对pyspark进行了交互测试，它工作正常。尝试创建sc时出现此错误：

File "test.py", line 10, in <module>
    conf=(SparkConf().setMaster('local').setAppName('a').setSparkHome('/home/dirk/spark-1.4.1-bin-hadoop2.6/bin'))
  File "/home/dirk/spark-1.4.1-bin-hadoop2.6/python/pyspark/conf.py", line 104, in __init__
    SparkContext._ensure_initialized()
  File "/home/dirk/spark-1.4.1-bin-hadoop2.6/python/pyspark/context.py", line 229, in _ensure_initialized
    SparkContext._gateway = gateway or launch_gateway()
  File "/home/dirk/spark-1.4.1-bin-hadoop2.6/python/pyspark/java_gateway.py", line 48, in launch_gateway
    SPARK_HOME = os.environ["SPARK_HOME"]
  File "/usr/lib/python2.7/UserDict.py", line 23, in __getitem__
    raise KeyError(key)
KeyError: 'SPARK_HOME'