Add a py.typed marker, per PEP 561

[gvanrossum]

(Might want to wait merging this until PEP 561 is accepted.)

[ilevkivskyi]

Does this mean that PEP 561 will not go into 3.7?

[gvanrossum]

Must have been a side-effect of prematurely cleaning out the branch.

FWIW I don't believe that there is any effect of PEP 561 on CPython, so I don't consider this urgent.

IIUC @ethanhs is still working on his implementation -- I'd like to play around with that before finalizing acceptance of his PEP (I believe he revised the PEP at least once as a result of something he encountered during implementation).

[emmatyping]

FWIW I don't believe that there is any effect of PEP 561 on CPython, so I don't consider this urgent.

Agreed, it doesn't need to be accepted before 3.7 lands.

IIUC @ethanhs is still working on his implementation -- I'd like to play around with that before finalizing acceptance of his PEP (I believe he revised the PEP at least once as a result of something he encountered during implementation).

Yes I am afraid I haven't had much time in the last month to work on it (or much of anything), but I hope to get back to it more this weekend.

[emmatyping]

Now that #4693 is merged I believe this can be merged too? (I will go ahead and fix the merge conflict). This should wait for the PEP to be accepted.

[gvanrossum]

Whoops pilot error. Will fix.

[gvanrossum]

Actually I was very thorough in my misguided scrubbing of this branch. @ethanhs do you still have a copy?

[emmatyping]

No I don't think so, I fixed the merge conflict online, so I don't have my own copy. Ah I see you fixed it.

[gvanrossum]

OK, new one is in $4879. Is there a reason not to merge this in 0.590?

[emmatyping]

I don't think so, no.

[gvanrossum]

Hm, then why did you say previously "This should wait for the PEP to be accepted"? (IIUC you even edited your comment to strike through "I believe this can be merged too?" and add that.)

[emmatyping]

You had said it should wait for the PEP to be accepted in the original comment. I have no reason to wait, so it's up to you. Apologies for the confusion.