Quicksort in Python

Question

I am a beginner in Python and i want to implement quicksort in my code. I need help in concatenating the three arrays and print them. how do i do it in the following code :

def sort(array=[18,4,5,9,7,1,3,12):
    less = []
    equal = []
    greater = []

    if len(array) > 1:
        pivot = array[0]
        for x in array:
            if x < pivot:
                less.append(x)
            if x == pivot:
                equal.append(x)
            if x > pivot:
                greater.append(x)
            sort(less)
            sort(pivot)
            sort(greater)

Answer 1

The following code may solve your problem:

def sort(array=[18,4,5,9,7,1,3,12]):
    less = []
    equal = []
    greater = []

    if len(array) > 1:
        pivot = array[0]
        for x in array:
            if x < pivot:
                less.append(x)
            if x == pivot:
                equal.append(x)
            if x > pivot:
                greater.append(x)
        # Don't forget to return value!
        return sort(less)+equal+sort(greater)  # use the + operator to join lists
    # Note that you want equal ^^^^^ not pivot
    else:  # You need to handle the part at the end of the recursion - when you only have one element in your array, just return the array.
        return array