I can't find anything specifically called "hasura actions". Found this[1], but that has nothing to do with language integration.
[1] https://docs.hasura.io/1.0/graphql/manual/guides/auditing-ta...
Perhaps it's possible to just use PL/Python[2] to write a custom stored prodecure?
[1] https://docs.hasura.io/1.0/graphql/manual/schema/default-val...