title: Python subprocess time calls /usr/bin/time instead of keyword
body: <p>I'm trying to get the time of a process, and when I use the keyword time in the shell, I get a nicer output as:</p>
  <pre><code>real    0m0,430s
  user    0m0,147s
  sys     0m0,076s
  </code></pre>
  <p>Instead of the <code>/usr/bin/time</code> which gives a different output. When I try to run it through python's subprocess library with <code>subprocess.call('time command args',shell=True)</code> it gives me the /usr/bin/time instead of the keyword. How can I use the keyword function as opposed to the current one?</p>