Bokeh HoverTool formating

Question

I have the Bokeh chart on the map with hover. The data comes from 3 df sources. All are geographical locations of events on the map. In some cases under one location there is only one event, but in tooltip the other 2 non existent events appears as ???

Here is my code:

wikimedia = get_provider(WIKIMEDIA)
output_file('Geological_Disasters.html')

#1

tooltips = [('Tsunami Location', '@{Location Name}'), ('Volcano', '@{Volcano Name}'),
        ('Earthquake Location', '@place')]
p = figure(plot_width=800, plot_height=600,
           x_range=(world_lon1, world_lon2), y_range=(world_lat1, world_lat2),
           x_axis_type="mercator", y_axis_type="mercator",
           tools="pan, box_select, zoom_in, zoom_out, save, reset, hover",
           tooltips=tooltips,
           title='Geological Disasters')

p.add_tile(wikimedia)

p.circle(x="MercatorX", y="MercatorY",
          source=tsunamis19_20)

# 2

p.circle(x="MercatorX", y="MercatorY",
         size=12,
         fill_alpha=0.8,
         source=volcano19_20)

#3

p.circle(x="MercatorX", y="MercatorY",
         size=3,
         fill_color="red", line_color="red",
         line_alpha=0.1,
         fill_alpha=0.1,
         source=earthquakes19_20)


show(p)
save(p)

Is there a way that I could configure the code to "not show event if name of locations" doesn't exist?

Thx