title: Get input file name in streaming hadoop program
body: <p>I am able to find the name if the input file in a mapper class using FileSplit when writing the program in Java.</p>
  
  <p>Is there a corresponding way to do this when I write a program in Python (using streaming?)</p>
  
  <p>I found the following in the hadoop streaming document on apache:</p>
  
  <blockquote>
    <p>See Configured Parameters. During the execution of a streaming job,
    the names of the "mapred" parameters are transformed. The dots ( . )
    become underscores ( _ ). For example, mapred.job.id becomes
    mapred_job_id and mapred.jar becomes mapred_jar. In your code, use the
    parameter names with the underscores.</p>
  </blockquote>
  
  <p>But I still cant understand how to make use of this inside my mapper.</p>
  
  <p>Any help is highly appreciated.</p>
  
  <p>Thanks</p>