Update app.py

app.py

@@ -1,6 +1,13 @@
+import os
+import sys
 import streamlit as st
 from SIR_model import main as run_sir_model
 
+# Add Graphviz bin directory to PATH
+graphviz_bin_dir = os.path.join(sys.prefix, "bin")
+os.environ["PATH"] += os.pathsep + graphviz_bin_dir
+
+
 # Streamlit app title
 st.title('SIR Model Simulation')