tooltip

app.py

@@ -119,7 +119,8 @@ hist = (
     .encode(
         x=alt.X("YTD Gross:Q", bin=True, title="YTD Gross (binned)"),
         y=alt.Y("count()", title="Count"),
-        color=alt.value("#4C78A8")
+        color=alt.value("#4C78A8"),
+        tooltip=[alt.tooltip("YTD Gross:Q",title="Range"),alt.tooltip("count():Q",title="Count")]
     )
     .transform_filter(select_bar)  
     .properties(width=400, height=300)