I've used PyCharm by Jetbrains on Windows/full blown Linux and I like the ability to step through code. However, due to the processor of the Raspberry Pi 3, it doesn't run very quickly. Can anyone recommend a Python IDE for Raspberry Pi 3 so I can debug on the fly (step through the code)? Stepping through the code is the most important element for me.
There are two more worth looking into:
They are both excellent - and free. Spyder is somewhat more feature-rich than Ninja and, so, a bit heavier (but still much lighter than PyCharm - they are so light, that you can run them on the Pi and get the GUI on your PC - through ssh -Y).
They can even, while running e.g. in your laptop, connect to the Python kernel of another server (e.g. Pi).
I've used them both (I prefer Spyder) and recommend them wholeheartedly.
Python's built-in IDLE IDE is far less resource-intensive than PyCharm, but still has a "debugger with persistent breakpoints, stepping, and viewing of global and local namespaces".
To make sure IDLE's installed, run:
sudo apt-get install idle
To open the debugger, click "Debug" in the top menu, then "Debugger". The "Debug Control" window will open, and the IDLE console will say "[DEBUG ON]". Then, any code that runs will go through the debugger, and can be stepped through as expected. A visual guide of what to expect is available here.
IDLE isn't quite as pretty as PyCharm, but you can still step through, monitor local and globals, set breakpoints, and so on. It should also run much more painlessly on the Pi, which is a bonus for productivity.
It's the new Python editor shipped with Stretch. It's fast and lean, and I find it easier to work with than Idle
sudo apt install python3-thonny
More info here