Understanding pdb result

[Rich Shepard]

   Running python3-3.6.5 and wxPython-4.0.1 on Slackware-14.2.

   The module begins this way:

#!/usr/bin/env python3

import sys, os
import pdb
import wx

   When pdb is invoked and I step through the code I get these results:

$ python3 -m pdb openEDMS.py
> /home/rshepard/development/openEDMS/openEDMS.py(8)<module>()
-> """
(Pdb) s
> /home/rshepard/development/openEDMS/openEDMS.py(10)<module>()
-> import sys, os
(Pdb) s
> /home/rshepard/development/openEDMS/openEDMS.py(11)<module>()
-> import pdb
(Pdb) 
> /home/rshepard/development/openEDMS/openEDMS.py(12)<module>()
-> import wx
(Pdb) --Call--
> <frozen importlib._bootstrap>(966)_find_and_load()
(Pdb)

   My web search suggests that I need to import importlib, but doing so does
not change the results.

   Please pass me a pointer to a resource that teaches me how to avoid this
error.

TIA,

Rich