feat: fix import error

app/streamlit/app.py

@@ -1,9 +1,28 @@
 #!/usr/bin/env python
 # coding: utf-8
 
+import base64
+from io import BytesIO
+
+import requests
 import streamlit as st
+from PIL import Image
+
+
+class ServiceError(Exception):
+    def __init__(self, status_code):
+        self.status_code = status_code
+
+
+def get_images_from_backend(prompt, backend_url):
+    r = requests.post(backend_url, json={"prompt": prompt})
+    if r.status_code == 200:
+        images = r.json()["images"]
+        images = [Image.open(BytesIO(base64.b64decode(img))) for img in images]
+        return images
+    else:
+        raise ServiceError(r.status_code)
 
-from .backend import ServiceError, get_images_from_backend
 
 st.sidebar.markdown(
     """