Has anyone seen python libraries for Event tree analysis (ETA)?

Question

Python

You need something like described here : there is a decision tree, in the nodes of which there are some questions with some probability of error in this question (for simplicity, you can imagine that this is a psychological test - but in fact it is not). for each sheet in which we came, we want to get the probabilities of all other sheets (that is, continuing the analogy - we got the test result, we need the probabilities of all other outcomes, taking into account the probabilities of errors).
For one specific tree, everything is clear (although it is a little lazy to count), but I want to implement a "constructor" of such trees, so that I can draw a tree, set errors at the nodes - get the mutual probabilities of outcomes.
I don’t want to reinvent the wheel, but Google stubbornly gives me decision trees, which are classification and regression trees, but they are just not needed - there is no mining date at this stage.