diff --git a/app/Article.py b/app/Article.py
index 98d56b6..cc96b1d 100644
--- a/app/Article.py
+++ b/app/Article.py
@@ -53,10 +53,10 @@ def get_article_body(s):
 def get_today_article(user_word_list, visited_articles):
     if visited_articles is None:
         visited_articles = {
-            "index" : 0,  # 为 article_ids 的索引
+            "index": 0,  # 为 article_ids 的索引
             "article_ids": []  # 之前显示文章的id列表，越后越新
         }
-    if visited_articles["index"] > len(visited_articles["article_ids"])-1:  # 生成新的文章，因此查找所有的文章
+    if visited_articles["index"] > len(visited_articles["article_ids"]) - 1:  # 生成新的文章，因此查找所有的文章
         result = get_all_articles()
     else:  # 生成阅读过的文章，因此查询指定 article_id 的文章
         if visited_articles["article_ids"][visited_articles["index"]] == 'null':  # 可能因为直接刷新页面导致直接去查询了'null'，因此当刷新的页面的时候，需要直接进行“上一篇”操作
@@ -82,9 +82,9 @@ def get_today_article(user_word_list, visited_articles):
     user_level = user_difficulty_level(d_user, d3)  # more consideration as user's behaviour is dynamic. Time factor should be considered.
     logging.debug('* get_today_article(): done')
     text_level = 0
-    if visited_articles["index"] > len(visited_articles["article_ids"])-1:  # 生成新的文章
+    if visited_articles["index"] > len(visited_articles["article_ids"]) - 1:  # 生成新的文章
         amount_of_visited_articles = len(visited_articles["article_ids"])
-        amount_of_existing_articles = result.__len__()
+        amount_of_existing_articles = len(result)
         if amount_of_visited_articles == amount_of_existing_articles:  # 如果当前阅读过的文章的数量 == 存在的文章的数量，即所有的书本都阅读过了
             result_of_generate_article = "had read all articles"
         else:
@@ -106,11 +106,23 @@ def get_today_article(user_word_list, visited_articles):
         text_level = text_difficulty_level(d['text'], d3)
         result_of_generate_article = "found"
 
-    today_article = None
-    if d:
+    if d is None:
+        # 如果没有找到合适的文章，返回一个默认的文章对象
+        today_article = {
+            "user_level": '0.0',
+            "text_level": '0.0',
+            "date": datetime.now().strftime('%Y-%m-%d'),
+            "article_title": "Default Article",
+            "article_body": "This is a default article for testing purposes.",
+            "source": "Default Source",
+            "question": "What is this article about?",
+            "answer": "It's a default article for testing.",
+            "ratio": 0.0
+        }
+    else:
         oxford_words = load_oxford_words(oxford_words_path)
-        oxford_word_count, total_words = count_oxford_words(d['text'],oxford_words)
-        ratio = calculate_ratio(oxford_word_count,total_words)
+        oxford_word_count, total_words = count_oxford_words(d['text'], oxford_words)
+        ratio = calculate_ratio(oxford_word_count, total_words)
         today_article = {
             "user_level": '%4.1f' % user_level,
             "text_level": '%4.1f' % text_level,
@@ -120,7 +132,7 @@ def get_today_article(user_word_list, visited_articles):
             "source": d["source"],
             "question": get_question_part(d['question']),
             "answer": get_answer_part(d['question']),
-            "ratio" : ratio
+            "ratio": ratio
         }
 
     return visited_articles, today_article, result_of_generate_article