TypeError: ‘type’ object is not subscriptable

Question

I’m trying to get the function below to run. However I’m getting an error saying

TypeError: ‘type’ object is not subscriptable 




def dist(loc1: tuple[float], loc2: tuple[float]) -> float:
    dx = loc1[0] - loc2[0]
    dy = loc1[1] - loc2[1]
    return (dx**2 + dy**2)**0.5

You need to show us how you are calling this. There's nothing wrong with that code. — Tim Roberts, Feb 08 '22 at 22:20
Upgrade Python, or use `typing.Tuple` instead of the builtin `tuple` in your type annotations. — Samwise, Feb 08 '22 at 22:21
@Tim Roberts, you can't say that it depends on how you call it when **it doesn't**. Running the above code alone produces the error in question. — Apostolos, Feb 20 '23 at 10:14

score 10 · Accepted Answer · edited Feb 08 '22 at 22:25

10

You need to use typing.Tuple, not the tuple class.

from typing import Tuple

def dist(loc1: Tuple[float], loc2: Tuple[float]) -> float:
    dx = loc1[0] - loc2[0]
    dy = loc1[1] - loc2[1]
    return (dx**2 + dy**2)**0.5
dist((1,2),(2,1)) # output 1.4142135623730951

edited Feb 08 '22 at 22:25

mkrieger1

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answered Feb 08 '22 at 22:20

tomerar

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But this is not necessary in newer Python versions (at least from 3.9 onwards). – 9769953 Feb 08 '22 at 22:21
Nor is it true in older versions, because you could also use `from __future__ import annotations`. Or use a forward reference, by putting the hint in quotes. – Martijn Pieters Dec 13 '22 at 14:59

TypeError: ‘type’ object is not subscriptable

1 Answers1