""" Generics thomas moll 2015 """ import random """ Here I've stolen our quick_sort implementation notice that I haven't modified anything to make it work with our fruit object. Pay close attention to the places in which the '<' is used. """ def quick_sort(arr, first, last): """ Quicksort Complexity: O(n log(n)) """ if first < last: pos = partition(arr, first, last) # Start our two recursive calls quick_sort(arr, first, pos-1) quick_sort(arr, pos+1, last) def partition(arr, first, last): pivot = first for pos in xrange(first, last): # This check happens naturally now that we've defined __cmp__ if arr[pos] < arr[last]: arr[pos], arr[pivot] = arr[pivot], arr[pos] pivot += 1 arr[pivot], arr[last] = arr[last], arr[pivot] return pivot class Fruit(object): def __init__(self, seeds, radius, name='fruit',): self.name = name self.number_of_seeds = seeds self.radius = radius def __str__(self): return 'Fruit:'+str(self.number_of_seeds) def __cmp__(self, other): # If the object I'm comparing myself to has more seeds # then it is considered higher in a list. self_value = self.number_of_seeds other_value = other.number_of_seeds return self_value - other_value if __name__ == '__main__': # Let's make some fruit apple = Fruit(3, 4, 'Apple') orange = Fruit(7, 3, 'Orange') # If an apple has fewer seeds... if apple < orange: print 'An apple has fewer seeds!' if apple > orange: print 'An orange has fewer seeds!' # Now let's see that sorting is unchanged fruit_basket = [ Fruit(random.randint(0,30), 4) for x in xrange(30)] print 'Before:' for fruit in fruit_basket: print str(fruit),',', print 'Sorting...' # Note: This method works because we're modifying fruit_basket # directly and not returning our sorted array. quick_sort(fruit_basket, 0, len(fruit_basket)-1) print 'After:' for fruit in fruit_basket: print str(fruit),',',