问题陈述：

我正在尝试使用pythonmrjob库在amazonemr中运行map reduce作业，但是在用必需的库和包引导节点时遇到了问题。

详情：

我的样品 python mrjob 代码：

import re
    from mrjob.job import MRJob
    from sentClassifier import sentClassify
    import nltk

    .. do something ..

有一些像nltk这样的库需要导入，还有一些我正在导入的本地模块 from sentClassifier import sentClassify 我想知道什么是最好的方式来引导emr节点，使这些方法和包是可用的。代码在我的本地机器上运行良好。
我的样品 mrjob.conf 文件：

runners:
      emr:
        aws_access_key_id:***
        aws_secret_access_key:***
        ec2_core_instance_type: m1.large
        ec2_key_pair: mykey
        ec2_key_pair_file: mykey.pem
        num_ec2_core_instances: 5
        pool_wait_minutes: 2
        pool_emr_job_flows: true
        ssh_tunnel_is_open: true
        ssh_tunnel_to_job_tracker: true
      hadoop:
        setup:
          - virtualenv venv
          - . venv/bin/activate
          - pip install mr3po simplejson
          - sudo easy_install https://code.google.com/p/nltk/downloads/detail?name=nltk-2.0b9-py2.6.egg&can=2&q=

但工作失败了。
我通读了以下参考资料，尝试了他们的各种方法，但仍然没有成功：
mrjob文档emr runner配置
mrjob文档hadoop runner配置
salmon run的博客文章
错误日志：

Scanning SSH logs for probable cause of failure
    Probable cause of failure (from ssh://ec2-54-86-50-115.compute-1.amazonaws.com!172.31.19.60/mnt/var/log/hadoop/userlogs/job_201405030101_0006/attempt_201405030101_0006_m_000002_3/stderr):
    Traceback (most recent call last):
    File "obidroidMR.py", line 5, in <module>
       import nltk
       ImportError: No module named nltk
       (while reading from s3://mrjob-   51b9493c1a467671/tmp/obidroidMR.shreyas.20140503.012933.336228/files/STDIN)
       Attempting to terminate job...
       Job appears to have already been terminated
       Killing our SSH tunnel (pid 12909)
       Traceback (most recent call last):
         File "obidroidMR.py", line 107, in <module>
         ObidroidReview.run()
         File "/Users/shreyas/anaconda/envs/obidroid/lib/python2.7/site-packages/mrjob/job.py", line 494, in run
         mr_job.execute()
         File "/Users/shreyas/anaconda/envs/obidroid/lib/python2.7/site-packages/mrjob/job.py", line 512, in execute
super(MRJob, self).execute()
         File "/Users/shreyas/anaconda/envs/obidroid/lib/python2.7/site-packages/mrjob/launch.py", line 147, in execute
         self.run_job()
         File "/Users/shreyas/anaconda/envs/obidroid/lib/python2.7/site-packages/mrjob/launch.py", line 208, in run_job
runner.run()
         File "/Users/shreyas/anaconda/envs/obidroid/lib/python2.7/site-packages/mrjob/runner.py", line 458, in run
self._run()
         File "/Users/shreyas/anaconda/envs/obidroid/lib/python2.7/site-packages/mrjob/emr.py", line 809, in _run
         self._wait_for_job_to_complete()
         File "/Users/shreyas/anaconda/envs/obidroid/lib/python2.7/site-packages/mrjob/emr.py", line 1599, in _wait_for_job_to_complete
         raise Exception(msg)
         Exception: Job on job flow j-2R8G1Q3RIE9ED failed with status WAITING: Waiting after step failed
         Probable cause of failure (from ssh://ec2-54-86-50-115.compute-1.amazonaws.com!172.31.19.60/mnt/var/log/hadoop/userlogs/job_201405030101_0006/attempt_201405030101_0006_m_000002_3/stderr):
         Traceback (most recent call last):
         File "obidroidMR.py", line 5, in <module>
         import nltk
         ImportError: No module named nltk

任何帮助都将不胜感激