Modern Python at the Large Synoptic Survey Telescope

Abstract: The LSST software systems make extensive use of Python, with almost all of it initially being developed solely in Python 2. Since LSST will be commissioned when Python 2 is end-of-lifed it is critical that we have all our code support Python 3 before commissioning begins. Over the past year we have made significant progress in migrating the bulk of the code from the Data Management system onto Python 3. This paper presents our migration methodology, and the current status of the port, with our eventual aim to be running completely on Python 3 by early 2018. We also discuss recent modernizations to our Python codebase.