.pth file does not show up in sys.path when configuring path.

[snippsat]

I find it easiest to not mess with PYTHONPATH for adding own folders permanently.
The site module offers a method that takes care of adding to sys.path without duplicates and with .pth files.
Make a sitecustomize.py file in C:\Python37\Lib\site-packages or your site-packages folder.

# sitecustomize.py
import site

site.addsitedir(r'E:\div_code')

Test that it work.

C:\
λ ptpython
>>> import sys
>>> from pprint import pprint

>>> pprint(sys.path)
['C:\\python37\\Scripts\\ptpython.exe',
 'c:\\python37\\python37.zip',
 'c:\\python37\\DLLs',
 'c:\\python37\\lib',
 'c:\\python37',
 'c:\\python37\\lib\\site-packages',
 'E:\\div_code']

For OS and Path look at Python 3.6/3.7 and pip installation under Windows