Is there a built-in Python function to add a custom package to the PYTHONPATH?

Question

Every time I need to use absolute import, for example:

from my_package.my_module import my_function

I declare my package to the $PYTHONPATH by writing down these code lines into my __ init __.py file located a the root of my package directory:

import sys
import os
sys.path.insert(0, os.getcwd())

But I find this solution totally inexpressive... Is this functionality natively supported by the Python standard library?