Python test code mangement and test directory structure

my directory structure given in image. I am writing test case using python 2.7 and flask sqlalchemy. So I want to create create separate test case modules for each source code module. So the question is where should I put test case directory which contain different modules for each source code module and what will be the structure of test directory. Note:- This project have only those functions which connect with database. For request management I have a different project which call this project functions.