selection_sort.py

data = [2, 9, 4, 8, 5, 6, 1]

def selection_sort(data, comp):
    for k in range(1, len(data)):
        for i in range(0, k):
            if comp(data[i], data[k]) > 0:
                temp = data[i]
                data[i] = data[k]
                data[k] = temp

def compare(x, y):
    return x - y

selection_sort(data, compare)               # ascendant order
print data

selection_sort(data, lambda x, y: y - x)    # descendant order
print data