title: Python: have check_call output to file continously?
body: <p>Is it possible to get the following <code>check_call</code> procedure:</p>
  
  <pre><code> logPath="log.txt"
   with open(logPath,"w") as log:
         subprocess.check_call(command, stdout = log, stderr=subprocess.STDOUT )
  </code></pre>
  
  <p>to output the <code>stdout</code> and <code>stderr</code> to a file <strong>continously</strong>?</p>
  
  <p>On my machine, the output is written to the file only after the <code>subprocess.check_call finished</code>.</p>
  
  <p>To achieve this, perhaps we could modify the buffer length of the <code>log</code> filestream?</p>