What colon (:) in Python mean in this case?

[snippsat]

There is a mistake in the tutorial,they have copy from PEP636 but forget the @dataclass .
So there see it's like this.

from dataclasses import dataclass

@dataclass
class Point:
    x: int
    y: int

def where_is(point):
    match point:
        case Point(x=0, y=0):
            print("Origin")
        case Point(x=0, y=y):
            print(f"Y={y}")
        case Point(x=x, y=0):
            print(f"X={x}")
        case Point():
            print("Somewhere else")
        case _:
            print("Not a point")

Then it work as it should.

>>> point = Point(0, 0)
>>> where_is(point)
Origin
>>> 
>>> point = Point(0, 9)
>>> where_is(point)
Y=9
>>> 
>>> point = Point(4, 0)
>>> where_is(point)
X=4
>>> 
>>> point = Point('hello', 'world')
>>> where_is(point)
Somewhere else