Python unique random function result decorator

I like messing around with random generators for productivity and creativity systems. Usually this involves functions that return a random value on each call. Even with quite a large set of possible values, duplicates occur more often than you might expect.

Here’s a quick Python decorator that keeps calling the function it decorates until it gets a value we haven’t seen so far during the current process:

def unique_results(func: Callable) -> Callable:
    seen = set()

    def wrapper():
        res = func()
        for i in range(100):
            if res not in seen:
                seen.add(res)
                return res
            res = func()
        raise OverflowError("Hit random value limit")

    return wrapper

Then you can decorate your random result function like this:

@unique_results
def random_thing() -> str:
    return random.choice(["Foo", "Bar", "Baz", "etc"])

I wouldn’t recommend this for use in any production application as it doesn’t attempt to be efficient, and just bails if it can’t get a unique value in 100 attempts. It’s fine for little local sandbox scripts, though.

Tech mentioned

• Python
• Functional