metlog-py is a Python client for the "Metlog" system of application logging and metrics gathering developed by the Mozilla Services team. The Metlog system is meant to make life easier for application developers with regard to generating and sending logging and analytics data to various destinations. It achieves this goal (we hope!) by separating the concerns of message generation from those of message delivery and analysis. Front end application code no longer has to deal directly with separate back end client libraries, or even know what back end data storage and processing tools are in use. Instead, a message is labeled with a type (and possibly other metadata) and handed to the Metlog system, which then handles ultimate message delivery.