python二叉树的创建代码

下面是Python中二叉树的创建代码，其中包括节点类和二叉树类：

class Node:
    def __init__(self, val=None):
        self.val = val
        self.left = None
        self.right = None


class BinaryTree:
    def __init__(self):
        self.root = None

    def insert(self, val):
        new_node = Node(val)
        if self.root is None:
            self.root = new_node
        else:
            queue = [self.root]
            while queue:
                curr = queue.pop(0)
                if curr.left is None:
                    curr.left = new_node
                    break
                elif curr.right is None:
                    curr.right = new_node
                    break
                else:
                    queue.append(curr.left)
                    queue.append(curr.right)

    def inorder_traversal(self, node):
        if node is not None:
            self.inorder_traversal(node.left)
            print(node.val, end=" ")
            self.inorder_traversal(node.right)

    def preorder_traversal(self, node):
        if node is not None:
            print(node.val, end=" ")
            self.preorder_traversal(node.left)
            self.preorder_traversal(node.right)

    def postorder_traversal(self, node):
        if node is not None:
            self.postorder_traversal(node.left)
            self.postorder_traversal(node.right)
            print(node.val, end=" ")

这里通过节点类和二叉树类来实现二叉树的创建，节点类中包含节点的值和左右子树指针，二叉树类中包含根节点指针以及插入节点、遍历等方法。其中插入节点的方法使用了广度优先搜索，遍历的方法分别是中序遍历、前序遍历、后序遍历。