Python实现堆数据结构

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2018/3/18 19:47
# @Author  : baoshan
# @Site    : 
# @File    : heap.py
# @Software: PyCharm Community Edition


# 堆数据结构
class Heap(object):
    def __init__(self):
        self.data_list = []

    def size(self):
        return len(self.data_list)

    def left_child(self, root):
        return root * 2 + 1

    def right_child(self, root):
        return root * 2 + 2

    def father(self, node):
        return (node - 1) // 2

    def heapify(self, root):
        if root > self.size() - 1:
            return
        left_node = self.left_child(root)
        right_node = self.right_child(root)
        largest = root
        if left_node <= self.size() - 1:
            if self.data_list[left_node] > self.data_list[largest]:
                largest = left_node

        if right_node <= self.size() - 1:
            if self.data_list[right_node] > self.data_list[largest]:
                largest = right_node

        if largest != root:
            self.data_list[root], self.data_list[largest] = self.data_list[largest], self.data_list[root]
            self.heapify(largest)

    def build_heap(self, dl):
        for i in range(len(dl) - 1, -1, -1):
            self.insert(dl[i])

    def get_max(self):
        if self.size() == 0:
            return None
        ret = self.data_list[0]
        self.data_list[0] = self.data_list[-1]
        del self.data_list[-1]
        self.heapify(0)
        return ret

    def insert(self, data):
        self.data_list.append(data)
        now_index = self.size() - 1
        pre = self.father(now_index)
        while now_index != 0 and self.data_list[pre] < data:
            self.data_list[pre], self.data_list[now_index] = self.data_list[now_index], self.data_list[pre]
            now_index = pre
            pre = now_index // 2


heap = Heap()
heap.insert(9)
heap.insert(10)
heap.insert(7)
heap.insert(12)
heap.insert(3)
heap.insert(4)
print(heap.get_max())
print(heap.get_max())
print(heap.get_max())
print(heap.get_max())
print(heap.get_max())
print(heap.get_max())
print('-' * 100)
heap.insert(10)
heap.insert(9)
heap.insert(8)
heap.insert(7)
heap.insert(7)
heap.insert(12)
print(heap.get_max())
print('-' * 100)
heap1 = Heap()
data_list = [1, 2, 3, 4, 5, 6, 7]
heap1.build_heap(data_list)
print(heap1.get_max())

输出结果：

/Library/Frameworks/Python.framework/Versions/3.5/bin/python3.5 /Users/baoshan/PycharmProjects/myProject/python_weixin_study/heap.py
12
10
9
7
4
3
----------------------------------------------------------------------------------------------------
12
----------------------------------------------------------------------------------------------------
7

Process finished with exit code 0

请大侠们指教！