Heapsort in Python

heapsort.py

'''Heapsort by Ritwik Dutta'''

class Heap(object):
    '''Heap Class'''

    def __init__(self, nums=None):
        self.nums = nums

    def heapify(self, n_index):
        ''' Heapify at given node'''
        size = len(self.nums)
        lc_index, rc_index = n_index * 2 + 1, n_index * 2 + 2
        lc_exists, rc_exists = lc_index < size, rc_index < size

        if lc_exists and rc_exists:
            tc_index = lc_index if self.nums[lc_index] > self.nums[rc_index] else rc_index
        elif lc_exists and not rc_exists:
            tc_index = lc_index
        elif rc_exists and not lc_exists:
            tc_index = rc_index
        else: return

        if self.nums[tc_index] > self.nums[n_index]:
            self.nums[tc_index], self.nums[n_index] = self.nums[n_index], self.nums[tc_index]

    def sort(self):
        '''Sort given nums'''
        sort = []
        while self.nums:
            l_tn = int(len(self.nums) / 2) - 1
            map(self.heapify, list(xrange(l_tn, -1, -1)))
            sort.insert(0, self.nums[0])
            self.nums = self.nums[-1::-1][:-1]
        return sort

HEAPSORT = lambda nums: Heap(nums).sort()