And since 3.8 the exponent can be negative, which lets you compute modular inverses without having to reimplement the extended Euclidean algorithm.

    >>> pow(5, -1, 13)
    8
    >>> 5 * 8 % 13
    1

Huh, it's the little things that are the neatest surpises. Having to write the EEA multiple times during my crypto class to do the homework was a real pain in the ass.