If you’re looking for an IDE to get familiar with Jython and what’s available, I’ve used PyCharm a fair amount with Jython.
As Paul said, though, if you’re looking to run your Ignition Python scripts, you won’t be able to do that from outside Ignition if they’re using anything Ignition-specific (which almost all of them normally do). Any system. functions need to be executed in Ignition directly, not in an external IDE, to function.
That said, if you do want to just write Python and play around with executing it in Jython, you can do so with the following steps:
You’ll want to install a separate copy of Jython on your system. Head over to jython.org and download the Jython Installer from the downloads page. Make sure your Java version is 11 to match Ignition 8’s.
After that, you can add Jython’s interpreter to PyCharm (Or possibly IDEA’s Python plugin, though I’ve never tried that myself), and you’re off to the races.
If the main reason you’re asking about an external IDE is for some of the nice features that most IDEs have, rest assured we have quite a few tickets in our system to improve our script editor / Python dev environment. It currently does fine, but there are quite a few things we could do to improve things in the future. Although it’s a ways off, we will certainly be making some improvements down the road.