本文只实现了二叉树基本的几种遍历，增、删、改、查，预计明天写完，后面的功能也尽量完善

class Node(object):
    def __init__(self, data):
        self.data = data
        self.lft = None #左节点
        self.rgt = None #右节点

先序遍历

class BTree(object):
    def __init__(self):
        self._root = None
        self._size = 0

    def preOrder(self):
        '''
        先遍历顺序：
        1，根节点
        2，遍历左子树
        3，遍历右子树
        '''
        btree = []
        
        def recurse(node):
            if node != None:
                btree.append(node.data)
                recurse(node.lft)
                recurse(node.rgt)
        
        recurse(self._root)
        return btree

class BTree(object):
    def __init__(self):
        self._root = None
        self._size = 0
    
    # 中序遍历
    def inOrder(self):
        '''
        中序遍历顺序：
        1，遍历左子树
        2，根节点
        3，遍历右子树
        '''
        btree = []
        
        def recurse(node):
            if node != None:
                recurse(node.lft)
                btree.append(node.data)
                recurse(node.rgt)
        
        recurse(self._root)
        return btree

class BTree(object):
    def __init__(self):
        self._root = None
        self._size = 0
    
    # 后序遍历
    def postOrder(self):
        '''
        后序遍历顺序：
        1，遍历左子树
        2，遍历右子树
        3，根节点
        '''
        btree = []
        
        def recurse(node):
            if node != None:
                recurse(node.lft)
                recurse(node.rgt)
                btree.append(node.data)
        
        recurse(self._root)
        return btree

from  collections import deque


class BTree(object):
    def __init__(self):
        self._root = None
        self._size = 0
    
    # 层序遍历
    def leverOrder(self):
        q = deque()
        q.append(self._root)
        btree = []
        while q:
            #dque是一个双向队列，先进先出是popleft
            node = q.popleft()
            btree.append(node.data)
            if node.lft:
                q.append(node.lft)
            if node.rgt:
                q.append(node.rgt)
        return btree

github 源码Btree源码