The idea of hiding information from the user, just for me to get it from bug tracking and support tickets is not something I could jive with.
Most errors are not?
Suppose you get KeyError. Is that information useful to the user?
The specific error (going to say in response to API given the article) you gave would likely be returned through the system as API response error tuple.
The parts of call stack higher up could determine if they want to show the error or swallow it. If it's a generic KeyError or MatchError, there's a 0% chance anything outside of the immediate call site could handle the error.