Re: How to connect docker container to bitcoin node?

You should use the internal IP on the Python container, not localhost.

Code:

connection_url="http://%s:%s@host.docker.internal:8332/wallet/testwallet"
credentials=('testuser','testpassword')
rpc_connection = AuthServiceProxy(connection_url % credentials)
rpc_connection.getnewaddress()

If it still not works, try to refer to https://www.howtogeek.com/devops/how-to-connect-to-localhost-within-a-docker-container/