Update app.py

app.py

@@ -187,7 +187,7 @@ def plot_graph_title(plot_df, stop, time):
     #st.line_chart(plot_df)
     # Create the Altair chart
     chart = alt.Chart(plot_df).mark_line(point=True, interpolate="step-after").encode(
-        x=alt.X('stop_name:N', title="Stop name"),  # Use column name as string
+        x=alt.X('stop_name:N', title="Stop name", sort=plot_df["stop_name"]),  # Use column name as string
         y=alt.Y('Occupancy:N', title="Vehicle Occupancy Status (Categories)", sort=category_order, scale=alt.Scale(domain=category_order)),  # Treat Y as categorical
         tooltip=["datetime", 'stop_name', 'Occupancy']  # Add tooltips for interactivity
     ).properties(