def split(p) Inferred type: (p: one of (str, unicode)) -> (one of (str, unicode, unknown),one of (str, unicode, unknown)) Split a pathname. Returns tuple "(head, tail)" where "tail" is everything after the final slash. Either part may be empty.
Did JetBrains (who make PyCharm) gather this information themselves, or is this kind of thing publicly available somewhere?
I'm a developer of PyCharm. We've created a type database for some parts of the standard library manually based on the docs. As for now, its format is an implementation detail of PyCharm, but we have some plans making it available and extendable for other people and tools. We also interested in efforts regarding the standardization of type annotations. We'll announce our plans later on, stay tuned.