Hover tool

The hover tool shows the related information whenever the mouse pointer is placed over a particular area. Let's see examples to understand the hovering plots:

# Import the required modules
from bokeh.plotting import figure 
from bokeh.plotting import output_notebook
from bokeh.plotting import show 
from bokeh.models import CategoricalColorMapper
from bokeh.models import HoverTool

# Import iris flower dataset as pandas DataFrame
from bokeh.sampledata.iris import flowers as df

# Output to notebook 
output_notebook() 

# Create color mapper for categorical column 
mapper = CategoricalColorMapper(factors=['setosa', 'virginica', 'versicolor'], 
                                palette=['blue', 'green', 'red'])

color_dict={'field': 'species','transform': mapper}

# Create hovertool and specify the hovering information
hover = HoverTool(tooltips=[('Species type','@species'),
          ...