title: how to import resource module?
body: <p>Today I see a python file starting with </p>
  
  <pre><code>import sys
  import time
  import heapq
  import resource
  from itertools import groupby
  from collections import defaultdict
  </code></pre>
  
  <p>however, after I run the file, the error showed with </p>
  
  <pre><code>ImportError: No module named resource 
  </code></pre>
  
  <p>then I try to install resource with pip install but cannot find such packages. </p>
  
  <p>Any idea could be helpful! </p>