The universe is expanding faster today than early cosmic measurements appear to allow. A proposed reversal in dark energy once seemed capable of closing that gap, but a sharper statistical test finds ...

You don't have to divide on the number of added parts, especially if your subjects are very different (e.g. not contain same tokens); By multiplying each part in second example (where X and Y are ...

These implementations are for demonstration purposes. They are less efficient than the implementations in the Python standard library.