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Type hints in namedtuple

2019-01-22 05:24发布

问题:

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?

回答1:

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 Data Classes (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)


回答2:

You can use typing.NamedTuple

From the docs

Typed version of namedtuple.

>>> import typing
>>> Point = typing.NamedTuple("Point", [('x', int), ('y', int)])

This is present only in Python 3.5 onwards