我只想在pyspark shell中使用hdfs.open，但出现以下错误：

16/06/20 16:11:40 WARN util.NativeCodeLoader: Unable to load native-hadoop 
libra                                                                                                             ry for your platform... using builtin-java classes where applicable
hdfsBuilderConnect(forceNewInstance=0, nn=xipcc01, port=8020, kerbTicketCachePat                                                                                                             h=(NULL), userName=(NULL)) error:
java.io.IOException: No FileSystem for scheme: hdfs
        at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:26                                                                                                             44)
        at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2651                                                                                                             )
        at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:92)
        at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:268                                                                                                             7)
        at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2669)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:371)
        at org.apache.hadoop.fs.FileSystem$1.run(FileSystem.java:160)
        at org.apache.hadoop.fs.FileSystem$1.run(FileSystem.java:157)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInforma                                                                                                             tion.java:1709)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:157)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/cloud/anaconda2/lib/python2.7/site-packages/pydoop/hdfs/__init_                                                                                                             _.py", line 121, in open
    fs = hdfs(host, port, user)
  File "/home/cloud/anaconda2/lib/python2.7/site-packages/pydoop/hdfs/fs.py",                                                                                                              line 150, in __init__
    h, p, u, fs = _get_connection_info(host, port, user)
  File "/home/cloud/anaconda2/lib/python2.7/site-packages/pydoop/hdfs/fs.py",                                                                                                              line 64, in _get_connection_info
    fs = core_hdfs_fs(host, port, user)
  File "/home/cloud/anaconda2/lib/python2.7/site-packages/pydoop/hdfs/core/__                                                                                                             init__.py", line 57, in core_hdfs_fs
    return _CORE_MODULE.CoreHdfsFs(host, port, user)
RuntimeError: (255, 'Unknown error 255')

有人有主意吗？在python中我可以使用hdfs.open函数-在pyspark中我不能访问namenode吗？我不明白为什么它在python中工作而在pyspark中不工作？
python 2.7（anaconda 4）spark 1.6.0 hadoop 2.4（与ambari一起安装）