Python libs can and do use dunder method overrides, operator overloading, and so on. If it was common to rewrite the AST, or have other action-at-a-distance, I'd give this some credit, but those are still century old PL features, and well specified mechanisms, not something one can't reason about.
Python I find to be (and I'd say most find it to be, hence its popularity on fields like Physics and such, even by non-programmers by trade) one of the easiest languages to read programs in and understand their intent.
Which exacly library, say of the 100 most commonly used ones on Pypi to keep this focused, is particularly problematic?