Python debugging in jupyter notebook

Question

I am trying to understand debugging in jupyter notebooks. As per my understanding applying breakpoint() is the way to go about it but I am landing into a few issues that I describe below. I have a file named test_debugger.py in ./ that I am using as a prop in my little understanding endeavor.

#./test_debugger.py

def fun1(a):
    print(a)
    breakpoint()
    if a > 3:
        print(a+1)
        breakpoint()
    print(a+2)
    breakpoint()
    return None

Setup:

from test_debugger import *

Issues:

• breakpoint() enters into debugging the interactive shell:

print(5)
breakpoint()
fun1(4)
breakpoint()

Running the above code gives me

5
--Return--
None
> <ipython-input-2-4276bdd18b42>(2)<module>()
      1 print(5)
----> 2 breakpoint()
      3 fun1(4)
      4 breakpoint()

ipdb> 

I press n and I want to jump to the next line in the cell but it gets into debugging the interactive shell I guess. Upon pressing nI get:

ipdb> n
    [... skipped 1 hidden frame]

    [... skipped 1 hidden frame]

    [... skipped 1 hidden frame]

    [... skipped 1 hidden frame]

> /home/nitin/miniconda/envs/nyraml386/lib/python3.8/site-packages/IPython/core/interactiveshell.py(3330)run_ast_nodes()
   3328                     to_run.append((node, 'single'))
   3329 
-> 3330                 for node,mode in to_run:
   3331                     if mode == 'exec':
   3332                         mod = Module([node], [])

ipdb> 

Question: How do I get the desired functionality of n (jump to next line in code written by me while remaining in the same function score) and s (jump to the next line in code written by me while switching the function scope wherever necessary).

• PYTHONBREAKPOINT not available in jupyter notebook

The behavior expected: I have read that in case I want to disable all breakpoint() then I can set the env variable PYTHONBREAKPOINT to manage the behavior of breakpoint(). Specifically, I can set PYTHONBREAKPOINT=0 to disable breakpoint()

The behavior seen: PYTHONBREAKPOINT is not a variable available at all in jupyter notebook. Even if I set it equal to 0 that does not alter the disable breakpoint(). It is as if nothing happened

Question: How to manage breakpoint() when operating in jupyter notebooks. What is the way to bring in PYTHONBREAKPOINT into the notebook