以二叉链表作为二叉树的存储结构，创建二叉树，并编写用层次顺序遍历二叉树的方法，统计树中度为1 的结点个数。

二叉链表存储结构中，每个结点包含三个域，分别是数据域、左子树指针域和右子树指针域。下面是用二叉链表创建二叉树的代码：

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

def create_binary_tree(node_list):
    """使用二叉链表创建二叉树"""
    if not node_list:
        return None
    root = TreeNode(node_list[0])
    nodes = [root]
    j = 1
    for node in nodes:
        if node is not None:
            node.left = TreeNode(node_list[j]) if node_list[j] is not None else None
            nodes.append(node.left)
            j += 1
            if j == len(node_list):
                return root
            node.right = TreeNode(node_list[j]) if node_list[j] is not None else None
            nodes.append(node.right)
            j += 1
            if j == len(node_list):
                return root
        else:
            nodes.append(None)
            nodes.append(None)
    return root

使用层次遍历的方法遍历二叉树，可以按照从上到下、从左到右的顺序依次遍历每个结点。下面是用层次遍历二叉树的代码：

from queue import Queue

def level_order_traversal(root):
    """层次遍历二叉树"""
    if not root:
        return []
    res = []
    queue = Queue()
    queue.put(root)
    while not queue.empty():
        node = queue.get()
        res.append(node.val)
        if node.left:
            queue.put(node.left)
        if node.right:
            queue.put(node.right)
    return res

统计树中度为1的结点个数，可以在遍历二叉树的过程中，记录每个结点的度数，然后统计度数为1的结点个数。下面是统计度数为1的结点个数的代码：

def count_degree_one_nodes(root):
    """统计树中度为1的结点个数"""
    if not root:
        return 0
    queue = Queue()
    queue.put(root)
    count = 0
    while not queue.empty():
        node = queue.get()
        degree = 0
        if node.left:
            degree += 1
            queue.put(node.left)
        if node.right:
            degree += 1
            queue.put(node.right)
        if degree == 1:
            count += 1
    return count

完整代码如下：

from queue import Queue

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

def create_binary_tree(node_list):
    """使用二叉链表创建二叉树"""
    if not node_list:
        return None
    root = TreeNode(node_list[0])
    nodes = [root]
    j = 1
    for node in nodes:
        if node is not None:
            node.left = TreeNode(node_list[j]) if node_list[j] is not None else None
            nodes.append(node.left)
            j += 1
            if j == len(node_list):
                return root
            node.right = TreeNode(node_list[j]) if node_list[j] is not None else None
            nodes.append(node.right)
            j += 1
            if j == len(node_list):
                return root
        else:
            nodes.append(None)
            nodes.append(None)
    return root

def level_order_traversal(root):
    """层次遍历二叉树"""
    if not root:
        return []
    res = []
    queue = Queue()
    queue.put(root)
    while not queue.empty():
        node = queue.get()
        res.append(node.val)
        if node.left:
            queue.put(node.left)
        if node.right:
            queue.put(node.right)
    return res

def count_degree_one_nodes(root):
    """统计树中度为1的结点个数"""
    if not root:
        return 0
    queue = Queue()
    queue.put(root)
    count = 0
    while not queue.empty():
        node = queue.get()
        degree = 0
        if node.left:
            degree += 1
            queue.put(node.left)
        if node.right:
            degree += 1
            queue.put(node.right)
        if degree == 1:
            count += 1
    return count

if __name__ == '__main__':
    node_list = [1, 2, 3, 4, None, 6, 7, None, None, None, None, None, None, 14]
    root = create_binary_tree(node_list)
    print(level_order_traversal(root))  # [1, 2, 3, 4, 6, 7, 14]
    print(count_degree_one_nodes(root))  # 2