quicksort function in python

Reference: https://cs231n.github.io/python-numpy-tutorial/

def quicksort(arr):
    if len(arr) <=1:
        return arr
    pivot = arr[len(arr)//2]
    print("pivot")
    print(pivot)
    left = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)