The final package will include "tests" folder which is not necessary in production

For the setup.py, we include the all the packages:

packages=setuptools.find_packages()

Actually, the tests folder will not be used in production, is that possible to exclude this tests folder to avoid the tests folder installed?

Start in setup.py at the setuptools.find_packages() call and inspect how the source package is assembled. Build the package and check its contents to confirm whether the tests folder is included; done means the production package no longer installs that folder while the intended packages remain available.

Written by the indexing model from the issue text.