Quick Sort (v1)

quicksort.py

def quick_sort(arr):
    smaller, equal, greater = [], [], []
    
    if len(arr) > 1:
        pivot = arr[0]
        for x in arr:
            if x < pivot:
                smaller.append(x)
            elif x == pivot:
                equal.append(x)
            else:
                greater.append(x)
                
        return quick_sort(smaller) + equal + quick_sort(greater)
    else:
        return arr
    
quick_sort([12,4,5,6,7,3,1,15])