VisIt is an open source, turnkey application for scientific data analysis and visualization that runs on a wide variety of platforms from desktops to petascale class supercomputers. VisIt’s core software infrastructure is written in C++, however Python plays a vital role in enabling custom workflows. Recent work has extended Python’s use in VisIt beyond scripting, enabling custom Python UIs and Python filters for low-level data manipulation. The ultimate goal of this work is to evolve Python into a true peer to our core C++ plugin infrastructure. This paper provides an overview of Python’s role in VisIt with a focus on use cases of scripted rendering, data analysis, and custom application development.