我目前正在学习一门大数据课程，我的一个项目是在本地设置的hadoop集群上运行mapper/reducer。
我一直在使用python和mrjob库。
下面是我当前的python代码，用于mapper/reducer。

from mrjob.job import MRJob
from mrjob.step import MRStep
import re
import os

WORD_RE = re.compile(r"[\w']+")
choice = ""

class MRPrepositionsFinder(MRJob):

def steps(self):
    return [
        MRStep(mapper=self.mapper_get_words),
        MRStep(reducer=self.reducer_find_prep_word)
    ]

def mapper_get_words(self, _, line):
    # set word_list to indicators, convert to lowercase, and strip whitespace
    word_list = set(line.lower().strip() for line in open("/hdfs/user/user/indicators.txt"))

    # set filename to map_input_file
    fileName = os.environ['map_input_file']
    # itterate through each word in line
    for word in WORD_RE.findall(line):
        # if word is in indicators, yield chocie as filename
        if word.lower() in word_list:
            choice = fileName.split('/')[5]
            yield (choice, 1)

def reducer_find_prep_word(self, choice, counts):
    # each item of choice is (choice, count),
    # so yielding results in value=choice, key=count
    yield (choice, sum(counts))

if __name__ == '__main__':
MRPrepositionsFinder.run()

当我尝试在hadoop集群上运行代码时-我使用了以下命令：

python hrc_discover.py /hdfs/user/user/HRCmail/* -r hadoop --hadoop-bin /usr/bin/hadoop > /hdfs/user/user/output

不幸的是，每次运行命令时都会出现以下错误：

No configs found; falling back on auto-configuration
STDERR: Error: JAVA_HOME is not set and could not be found.
Traceback (most recent call last):
  File "hrc_discover.py", line 37, in 
    MRPrepositionsFinder.run()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/job.py", line 432, in run
    mr_job.execute()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/job.py", line 453, in execute
    super(MRJob, self).execute()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/launch.py", line 161, in execute
    self.run_job()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/launch.py", line 231, in run_job
    runner.run()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/runner.py", line 437, in run
    self._run()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/hadoop.py", line 346, in _run
    self._find_binaries_and_jars()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/hadoop.py", line 361, in _find_binaries_and_jars
    self.get_hadoop_version()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/hadoop.py", line 198, in get_hadoop_version
    return self.fs.get_hadoop_version()
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/fs/hadoop.py", line 117, in get_hadoop_version
    stdout = self.invoke_hadoop(['version'], return_stdout=True)
  File "/usr/lib/python3.5/site-packages/mrjob-0.6.0.dev0-py3.5.egg/mrjob/fs/hadoop.py", line 172, in invoke_hadoop
    raise CalledProcessError(proc.returncode, args)
subprocess.CalledProcessError: Command '['/usr/bin/hadoop', 'version']' returned non-zero exit status 1

我环顾了一下互联网，发现我需要导出我的java\u home变量-但我不想设置任何可能破坏我的设置的东西。
任何帮助都将不胜感激，谢谢！