Type hints in namedtuple

python python-3.x type-hinting namedtuple python-dataclasses

Pavel Hanpari · Dec 14, 2015 · Viewed 37k times · Source

Consider following piece of code:

from collections import namedtuple
point = namedtuple("Point", ("x:int", "y:int"))

The Code above is just a way to demonstrate as to what I am trying to achieve. I would like to make namedtuple with type hints.

Do you know any elegant way how to achieve result as intended?

Answer

The prefered Syntax for a typed named tuple since 3.6 is

from typing import NamedTuple

class Point(NamedTuple):
    x: int
    y: int = 1  # Set default value

Point(3)  # -> Point(x=3, y=1)

Edit Starting Python 3.7, consider using dataclasses (your IDE may not yet support them for static type checking):

from dataclasses import dataclass

@dataclass
class Point:
    x: int
    y: int = 1  # Set default value

Point(3)  # -> Point(x=3, y=1)