Python - How to Make Type Hint for the Tuple With Undetermined Number of Strings?

To make a type hint for a tuple with an undetermined number of strings in Python, you can use the Tuple and Union types from the typing module. Here's an example:

from typing import Tuple, Union

def process_strings(strings: Tuple[Union[str, ...], ...]) -> str:
    return ", ".join(strings)

strings1 = ("hello", "world")
strings2 = ("foo", "bar", "baz")

print(process_strings(strings1))  # Output: "hello, world"
print(process_strings(strings2))  # Output: "foo, bar, baz"

In the type hint above, Tuple is used to indicate that we are working with a tuple, and Union is used to indicate that each element of the tuple can be either a str or an ellipsis (...), which represents an infinite number of str elements. The second ... indicates that the tuple can contain an undetermined number of elements.

How to Use Elypsis in Type Hints to Indicate Arbitrary Number of Elements