This still doesn't seem to be working.
Still timing out, and I had an issue with the length of a float being exceeded.

Don't worry, sometimes it's a matter of reading the description a couple of times until it clicks, cheers.

You're confusing what you need to return, it's not how many spaces are left, it's how many people can't fit in the bus. Check the example usage in the description (I feel a deja vu).

There is nothing to fix, unless you can prove there is. ;)

cap is the amount of people the bus can hold excluding the driver.

^ That, also in the kata's description. Short for capacity I guess.

If there is enough space, return 0, and if there isn't, return the number of passengers he can't take.

cap is 20, there are 5 people already on, and 5 waiting to get on. Why do you think the tests are wrong?

done

Someone please approve this Python fork to resolve this

That is something for you to figure out :)