Classes lack __annotations__ (PEP-526)

With python 3.7 dataclasses were introduced. They work just fine in Cython except for their standard init function.

How to reproduce: test.pyx

from dataclasses import dataclass

@dataclass
class TestClass:
	x: int
	y: int
	some_string: str

This file compiles to Cython code just fine. However, when ran from the python it raises an error: test2.py

import test

test_class = test.TestClass(1, 2, 'string')

This raises the following:

Traceback (most recent call last):
  File ".\test2.py", line 3, in <module>
    test_class = test.TestClass(1, 2, 'string')
TypeError: __init__() takes 1 positional argument but 4 were given

if you rename test.pyx to test.py and do not compile it, no such error occurs.

my current workaround: setting each property after initialization separately: test.pyx remains unchanged. test.py

import test

test_class = test.TestClass()
test_class.x = 1
test_class.y = 2
test_class.some_string = 'string'

[GliderGeek]

awesome news that this is implemented 🎉 thanks a lot

[GliderGeek]

thanks for the quick reply. i will try to get some proper time to work on this. in the meantime i have tried a little workaround:

class Annotated:
    x: int
    y: int 

    __annotations__ = {'x': int, 'y': int}

this seems to work properly. is this what you meant by "get away with building the dict in Python and adding it to the class dict "?