Unable to install package “retrying” in python 3.7

Question

I am using Ubuntu and I have a code which needs to install various libraries. I mostly use python2.7, but due to some libraries this code uses, I had to move to python3, these libraries are

import urllib.request
import urllib.parse
import urllib.error

But then there was one library import which I could not import in python3, after searching on Google, I found that moving to python3.7 will solve the issue, and it did solve. Import was
from json import JSONDecodeError

But now I have the issue of 'from retrying import retry' ......After installing it with pip and pip3, I could import it in Python2.7 and python3, but I am failing to import it in python3.7.....

So, basically I am jumping across python versions to import the libraries required to run the code of an ex company employee....Please guide me how to import "retrying" in python3.7 or any way I can just install all the below ones in one python version

import urllib.request
import urllib.parse
import urllib.error
from json import JSONDecodeError
from retrying import retry

Answer 1

I installed python3.5, and everything worked fine in it. Weird it did not work in python3.7, anyways my issue is resolved.