# Quicksort with Python

## Issue

I am totally new to python and I am trying to implement quicksort in it.

I do not know how to concatenate the three arrays and printing them.

``````def sort(array=[12,4,5,6,7,3,1,15]):
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)
``````

## Solution

``````def sort(array=[12,4,5,6,7,3,1,15]):
"""Sort the array by using quicksort."""

less = []
equal = []
greater = []

if len(array) > 1:
pivot = array[0]
for x in array:
if x < pivot:
less.append(x)
elif x == pivot:
equal.append(x)
elif x > pivot:
greater.append(x)
# Don't forget to return something!
return sort(less)+equal+sort(greater)  # Just 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
``````

Answered By – Brionius

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