Displaying only one tooltip when using the HoverTool() tool

The posted CSS solutions did not work for me with Bokeh 2.2.2. The following did:

    div.bk-tooltip.bk-right>div.bk>div:not(:first-child) {
        display:none !important;
    }
    div.bk-tooltip.bk-left>div.bk>div:not(:first-child) {
        display:none !important;
    }

Not the most elegant solution but it ended my frustration with 40 tooltips stacking vertically. This was implemented with an embedded chart on a website with custom CSS.

I was having a similar problem and came up with a solution using a custom tooltip. I insert a style tag at the top that only displays the first child div under the .bk-tooltip class, which is the first tooltip.

Here's a working example:

from bokeh.plotting import figure, show
from bokeh.models import HoverTool, Range1d

custom_hover = HoverTool()

custom_hover.tooltips = """
    <style>
        .bk-tooltip>div:not(:first-child) {display:none;}
    </style>

    <b>X: </b> @x <br>
    <b>Y: </b> @y
"""

p = figure(tools=[custom_hover]) #Custom behavior
#p = figure(tools=['hover'])  #Default behavior 

p.circle(x=[0.75,0.75,1.25,1.25], y=[0.75,1.25,0.75,1.25], size=230, color='red', fill_alpha=0.2)
p.y_range = Range1d(0,2)
p.x_range = Range1d(0,2)

show(p)

This is kind of a hacky solution, but it works in Safari, Firefox and Chrome. I think they'll be coming out with a more long-term solution soon.