[RFC] split up _pytest.python

[RonnyPfannschmidt]

this tries to split up _pytest.python by topic

the module is quite large and that makes it a pain to refactor certain details

i want to trim bits down so its more easy to eventually turn FunctionDefinition from a gruesome hack into a part of the collection tree

the initial split is not per se targeting good locations or complete

but its a discussion starter and i intend to change details until we hit a nice split that separates code in a manageable way

[nicoddemus]

I definitely like the idea. 👍

[nicoddemus]

Is this intentional? If so this should count as a breaking change, I think.

[RonnyPfannschmidt]

Good catch, refactoring tool mistake

[bluetech]

With this refactoring, python.nodes imports from python.metafunc and vice-versa. To me this means that neither module can be understood in isolation. I am -0.5 on splitting in this state, as it doesn't really help IMO.

From my experience with pytest code all of the core is intertwined so it might be hard to pull off, but it's a good goal :)

[RonnyPfannschmidt]

Part of my goal here is to get to a state where the interdependency is more clearly painful so that detangle in small steps gets attainable

Sometime in the future I want most collection code in nodes, and functions split such that Only function definition will import from meta func