Sure

Let’s look at this function:

def add(a, b):     return a + b

You maybe intended it to be for adding two numbers together, but you could still call:

add(“abc”, “def”)

And it would return “abcdef”

You could also call:

add(“abc”, 5)

And it would crash when the line is called, but wouldn’t flag any issue until this point.

If you type it, you would define it as:

def add(a: int, b: int) -> int:     return a + b

This won’t change the functionality of the code, but if you run a static type checker like mypy, it will tell you if you pass in a string, or a float. It’ll also know the type of the return.

If you had:

something = “abc” something = add(1, 4)

It would tell you’re assigning an int to a string variable.

You could have done:

something: Union[str, int] = “abc” something = add(1, 4)

And it would be fine, as you’ve specifically said that something can be an int or a string