Python exceptions in Docker logs marked as stream: stdout

Question

I want parse and handle all errors from docker container, but python exceptions marked as stdout, when I expect stderr.

As example simple app.py

Answer 1

Apart from the previous answer (and my comment), there is the attach of docker run from the doc http://docs.docker.com/reference/commandline/cli/#run -a, --attach=[] Attach to STDIN, STDOUT or STDERR