EnSight supports the connection to an external Python interpreter via the PyEnSight module. PyEnSight is an open-source project, downloadable as a Python wheel from PyPi, allowing you to launch and manage EnSight instances as a service. The documentation is accessible here:
You can run commands using the same syntax of the embedded EnSight Python interpreter, with the advantage of being able to write and debug EnSight/PyEnSight scripts inside of a native Python IDE.
PyEnSight also offers access to the visualization systems of EnSight, via images, geometry files and remote HTML rendering. In combination with the support of the object event system, PyEnSight allows you to develop asynchronous, remote or desktop applications which use the EnSight features in the background but that can run outside of EnSight.
Additional links: