Create custom data type in Python

Question

Hopefully the title isn't too misleading, I'm not sure the best way to phrase my question.

I'm trying to create a (X, Y) coordinate data type in Python. Is there a way to create a "custom data type" so that I have an object with a value, but also some supporting attributes?

So far I've made this simple class:

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.tuple = (x, y)

Ideally, I'd like to be able to do something like this:

>>> p = Point(4, 5)
>>>
>>> my_x = p.x    # can access the `x` attribute with "dot syntax"
>>>
>>> my_tuple = p  # or can access the tuple value directly
                  # without needing to do `.tuple`, as if the `tuple`
                  # attribute is the "default" attribute for the object

NOTE I'm not trying to simply display the tuple, I know I can do that with the __repr__ method

In a way, I'm trying to create a very simplified numpy.ndarray, because the ndarrays are a datatype that have their own attributes. I tried looking thru the numpy source to see how this is done, but it was way over my head, haha.

Any tips would be appreciated!

Answer 1

Python 3.12+

PEP 695 introduces a new, more compact and explicit way to create generic classes and functions. In addition, the PEP introduces a new way to declare type aliases using the type statement, which creates an instance of TypeAliasType. As a result, you can do this:

type Point = tuple[float, float]
# or
type Point[T] = tuple[T, T] # more generic

For example, you can use it like this:

type Point = tuple[int, int]
p: Point = (0,0)
print(p) # (0,0)

p = (4,5) # re-assign Point p
print(p[0]) # 4, your "x" 
print(p[1]) # 5, your "y"

Depending on your use case, this answer may not be relevant.