def container_running(self, container_name):
filters = {<EOL>"<STR_LIT:name>": container_name,<EOL>"<STR_LIT:status>": "<STR_LIT>",<EOL>}<EOL>for container in self.client.containers.list(filters=filters):<EOL><INDENT>if container_name == container.name:<EOL><INDENT>return container<EOL><DEDENT><DEDENT>return None<EOL>
Finds out if a container with name ``container_name`` is running.

:return: :class:`Container <docker.models.containers.Container>` if it's running, ``None`` otherwise.
:rtype: Optional[docker.models.container.Container]