Create a new virtual environment:
virtualenv -p python3.7 env
To activate the environment:
source env/bin/activate
Then run:
pip install -r requirements.txt
Afterwards, to run the webserver:
python main.py
To test with gcloud SDK, first get out of the virtual environment:
deactivate
Then run the gcloud SDK shortcut to set up a temporary local GAE instance supporting Python 3.7:
dev_appserver.py app.yaml