import function from a file in the same folder
Have you tried
import app.config as Config
It did the trick for me.
# imports all functions
import config
# you invoke it this way
config.my_function()
or
# import specific function
from config import my_function
# you invoke it this way
my_function()
If the app.py is invoked not from the same folder you can do this:
# csfp - current_script_folder_path
csfp = os.path.abspath(os.path.dirname(__file__))
if csfp not in sys.path:
sys.path.insert(0, csfp)
# import it and invoke it by one of the ways described above
To import from the same folder you can do:
from .config import function_or_class_in_config_file
or to import the full config with the alias as you asked:
from ..app import config as Config