Update app.py

app.py

@@ -36,7 +36,7 @@ st.toggle(label="Webcam",  help="Click on to use webcam, off to upload a file",
 # Use state to know whether to show file_uploader or webcam
 if st.session_state['upload_choice'] == 'file_up':
     img = st.file_uploader(label="Upload a photo of a squirrel or bird", type=['png', 'jpg'])
-    if len(img) > 0:
+    if img is not None:
         st.session_state['number_of_files'] = 1
     else:
         st.session_state['number_of_files'] = 0