Update app.py

app.py

@@ -92,11 +92,16 @@ if uploaded_file is not None:
             plt.xticks(rotation='vertical')
             st.pyplot(fig)
 
+        # Weekly Activity Map (Heatmap)
         st.title("Weekly Activity Map")
         user_heatmap = helper.activity_heatmap(selected_user, df)
-        fig, ax = plt.subplots()
-        ax = sns.heatmap(user_heatmap)
-        st.pyplot(fig)
+
+        if not user_heatmap.empty and user_heatmap.notnull().values.any():
+            fig, ax = plt.subplots()
+            ax = sns.heatmap(user_heatmap)
+            st.pyplot(fig)
+        else:
+            st.write("Insufficient data to generate a heatmap.")
 
         # Finding the busiest users in the group (Group level)
         if selected_user == 'Overall':