Most logging systems tell you what happened in your application, whereas eliot also tells you why it happened.

eliot is a Python logging system that outputs causal chains of actions: actions can spawn other actions, and eventually they either succeed or fail. The resulting logs tell you the story of what your software did: what happened, and what caused it.

Eliot works well within a single process, but can also be used across multiple processes to trace causality across a distributed system. Eliot is only used to generate your logs; you will still need tools like Logstash and ElasticSearch to aggregate and store logs if you are using multiple processes.

Eliot supports Python 2.7, 3.4, 3.5, 3.6, 3.7 and PyPy. It is maintained by Itamar Turner-Trauring, and released under the Apache 2.0 License.

• Read the documentation.
• Download from PyPI.
• Need help or have any questions? File an issue on GitHub.

"Eliot has made tracking down causes of failure (in complex external integrations and internal uses) tremendously easier. Our errors are logged to Sentry with the Eliot task UUID. That means we can go from a Sentry notification to a high-level trace of operations—with important metadata at each operation—in a few seconds. We immediately know which user did what in which part of the system."

—Jonathan Jacobs