"Reaching into a library" means depending on something not meant to be public, with the understanding that it is undocumented and subject to change without noti

"Reaching into a library" means depending on something not meant to be public, with the understanding that it is undocumented and subject to change without notice. Giving a reliable but soft warning (through quasi-encapsulation naming conventions and explicit module exports) and assuming developer maturity is the typical Python approach to double-edged features. Hacking something with private library parts doesn't involve any more "introspection" and "internals" than reading the library's code and finding useful loot to steal; metaprogramming is a completely different and orthogonal way to compromise code maintainability.