$1\mathrm{.}2[2$ pt$]$ Write a function called det$\_$and$\_$inv that takes as an input a square matrix $($a numpy array$)$ and returns a tuple with two elements $($a$)$ the determinant, and $($b$)$ the inverse if it mathematically exists and the string "does not exist" otherwise:

$]$: import numpy as np

def det$\_$and$\_$inv$($matrix$)$:

matrix