python multiprocessing.Array typing

When creating an array, I want to put it inside a dataclass, but I cannot find the type of the returned object.

arr = multiprocessing.RawArray("i", 2)

If I do:

>>> type(arr)
<class 'multiprocessing.sharedctypes.c_long_Array_2'>

but multiprocessing.sharedctypes.c_long_Array_2 does not exists.
How can I use type hints, e.g arr: the_type with multiprocessing Array?

UPDATE
Pycharm example when using typing ctypes.c_long * 2, there’s still a value attribute which is invalid.

Answer

The shared array’s type is derived from the ctypes module. You could also perhaps use this module to help you be more explicit about the data type of the array:

import multiprocessing
import ctypes # This is what you're looking for

# Your function that you want to type-hint for
def func(arr: ctypes.c_long * 2):
    # Some operations
    ...

# Being explicit about which c-type i want my array to be
arr = multiprocessing.RawArray(ctypes.c_long, 2)

# This evaluates to true
print(isinstance(arr, ctypes.c_long * 2))

Note: ctypes does not come with all the possibilities of array sizes so notice the ctypes.c_long * 2 syntax to indicate that it is an array of long of size = 2.