title: Python exceptions in Docker logs marked as stream: stdout
body: <p>I want parse and handle all errors from docker container, but python exceptions marked as stdout, when I expect stderr.</p>
  
  <p>As example simple <strong>app.py</strong></p>
  
  <pre><code>raise Exception("!")
  </code></pre>
  
  <p>Then I run this file in docker container.
  But in <strong>/var/lib/docker/containers/.../...-json.log</strong>:</p>
  
  <pre><code>{"log":"Traceback (most recent call last):\n","stream":"stdout","time":"2015-06-17T23:10:01.58636849Z"}
  {"log":"  File \"/var/app.py\", line 1, in \u003cmodule\u003e\n","stream":"stdout","time":"2015-06-17T23:10:01.586581081Z"}
  {"log":"    raise Exception(\"!\")\n","stream":"stdout","time":"2015-06-17T23:10:01.586842665Z"}
  {"log":"Exception: !\n","stream":"stdout","time":"2015-06-17T23:10:01.587373678Z"}
  </code></pre>