Setting the correct type for an empty tuple that later becomes a tuple of a specific type

user_17182863 0
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I have a python function that looks as following:

from typing import Tuple

def test() -> Tuple[int]:
    o: Tuple[int] = ()
    for i in range(2):
        o+=(i,)
    return o

Evaluating this with mypy returns the errors

error: Incompatible types in assignment (expression has type "Tuple[]", variable has type "Tuple[int]")
error: Incompatible types in assignment (expression has type "Tuple[int, int]", variable has type "Tuple[int]")

Assigning the tuple and return value the type Tuple without the int specification resolves this problem. I would like to specify the contents of the tuple as well though. How can I achieve this?

mypy type-hinting python
2 Answers
user_92960930

With regard to type hints, Tuple is not like List.

Tuple[int] means "a tuple of 1 int"

Tuple[int, int] means "a tuple of 2 ints"

List[int] means "a list of ints"

user_90962640
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