sort in python

mergesort.py

#The merge method takes in the two subarrays and creates a output array
def merge(left, right):
  result = []
	i , j = 0 , 0
	while i < len (left) and j < len (right): # iterate through both arrays and arrange the elements in sorted order
		if left[i] <= right [j]:
			result.append(left[i])
			i+=1
		else:
			result.append(right[j])
			j+=1

#The loop may break before all elements are copied hence append the remaining elements
	result += left[i:]
	result += right[j:]
	return result


#The mergesort method to split the arrays into smaller subarrays
def mergesort(lst):
	if len(lst) <= 1:
		return lst
	middle = int(len(lst) / 2)
	left = mergesort(lst[:middle])
	right = mergesort(lst[middle:])
	return merge(left, right)


if __name__ == '__main__':
	print mergesort([3, 4, 8, 0, 6, 7, 4, 2, 1, 9, 4, 5])

quicksort.py

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)
        # 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 hande the part at the end of the recursion - when you only have one element in your array, just return the array.
        return array

quicksort_inplace.py

def partition(array, begin, end):
    pivot = begin
    for i in xrange(begin+1, end+1):
        if array[i] <= array[begin]:
            pivot += 1
            array[i], array[pivot] = array[pivot], array[i]
    array[pivot], array[begin] = array[begin], array[pivot]
    return pivot



def quicksort(array, begin=0, end=None):
    if end is None:
        end = len(array) - 1
    def _quicksort(array, begin, end):
        if begin >= end:
            return
        pivot = partition(array, begin, end)
        _quicksort(array, begin, pivot-1)
        _quicksort(array, pivot+1, end)
    return _quicksort(array, begin, end)