Update app.py

app.py

@@ -271,7 +271,8 @@ col1, col2 = st.columns([3,3])
 with col1:
 
     uploaded_image = st.file_uploader("上传作文图片", type=["jpg", "png", "jpeg"])
-    st.image(uploaded_image, caption="已上传的图片。", use_column_width=True)
+    if uploaded_image:
+        st.image(uploaded_image, caption="已上传的图片。", use_column_width=True)
     st.session_state.essay = st.text_area(
     " 输入你的作文",
     height= 400