Update app.py

app.py

@@ -81,6 +81,10 @@ st.subheader("Upload a Python file with Chinese comments", divider='rainbow')
 # 文件上传
 uploaded_file = st.file_uploader("Choose .py file", type=['py'], label_visibility='collapsed')
 
+# 添加开始翻译按钮
+if uploaded_file:
+    st.button("开始翻译 / Start Translation", type="primary")
+
 # 初始化模型
 if 'models_loaded' not in st.session_state:
     with st.spinner('Loading models...'):
@@ -219,8 +223,8 @@ if st.session_state.processed:
                     avg_ppl = sum(ppl for _, ppl in st.session_state.scores) / len(st.session_state.scores)
                     st.metric("Average Perplexity", f"{avg_ppl:.4f}", help="Lower is better (Typical range: 1~100+, lower means better translation)")
             
-        # 下载按钮容器（修改点2：独立容器实现居中）
-        with st.container():
+            # 下载按钮容器（修改点2：在指标下方居中显示）
+            st.markdown("---")
             cols = st.columns([1, 2, 1])
             with cols[1]:
                 with tempfile.NamedTemporaryFile(suffix='.py', delete=False) as tmp:
@@ -232,5 +236,5 @@ if st.session_state.processed:
                         data=f,
                         file_name=f"translated_{uploaded_file.name}",
                         mime='text/x-python',
-                        use_container_width=False
+                        use_container_width=True
                     )