How to debug external .py functions run from Jupyter/IPython notebook

Question

My Jupyter/IPython notebook executes functions in an external .py.

I need to set breakpoints within these functions, inspect variables, single step, etc.

It just isn't practical to use a combination of print statements and throwing exceptions to early-exit a cell.

I need some kind of workflow.

Is it possible to hook up some third-party editor/IDE to view the .py and somehow connect it to the Python runtime Jupyter/IPython is using?

So that if I set a breakpoint in my external .py using my IDE and execute a cell in the notebook which encounters said breakpoint, I can continue to navigate manually from within the IDE.

EDIT: I've found https://pypi.python.org/pypi/ipdb https://www.quora.com/What-are-your-favorite-tricks-for-IPython-Notebook

EDIT https://www.youtube.com/watch?v=Jb2HHOahvcE <-- this video is getting close to what I'm after, I just can't quite see how to put it all together. That video demonstrates spyder which is an IDE with an IPython prompt... I wonder if maybe I can run my notebook through the prompt and debug it.

EDIT: It looks as though PyCharm does exactly what I'm after: https://www.jetbrains.com/help/pycharm/2016.1/tutorial-using-ipython-jupyter-notebook-with-pycharm.html

EDIT: I'm in the middle of trying to get PyCharm to behave. I will provide the details in an answer if I sort it out.

Answer 1

In Jupyter, you can use python debugger by adding below two lines for a breakpoint.

import pdb
pdb.set_trace()

Code execution will pause at this step and will provide you text box for debugging python code. I have attached screenshot for same.

You can refer to pdb documentation for the operations you can perform apart from printing your variables