Ensure you have thrift installed. On the Mac, you can run
brew install thrift

Then to generate the thrift files:
thrift -r -gen py tutorial.thrift


Finally:
pip install -r requirements.txt

And open client.py, and change the line:
host='server', port=9090 to host='localhost', port=9090


Then open two terminals:

Terminal 1
python server.py

Terminal 2
python client.py

docker-compose up --build Ah... Much simpler.