处理了“注册之后跳出文章获取错误，today_article为空”的bug，但并未真正获取文章数据，只是增加了一个测试文章

app/Article.py

@@ -84,7 +84,7 @@ def get_today_article(user_word_list, visited_articles):
     text_level = 0
     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:
@@ -106,8 +106,20 @@ 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)