bokeh_html_hover.py

# This is based on code examples here
# https://docs.bokeh.org/en/latest/docs/user_guide/tools.html
# And has been modified to be abstracted better.

import json
from pathlib import Path

import numpy as np
from bokeh.embed import json_item
from bokeh.io import output_file, show
from bokeh.models import ColumnDataSource, HoverTool
from bokeh.plotting import figure
from bokeh.sampledata.stocks import AAPL


def main(viz_type="web"):
    def datetime(x):
        return np.array(x, dtype=np.datetime64)

    source = ColumnDataSource(
        data={
            "date": datetime(AAPL["date"][::10]),
            "adj close": AAPL["adj_close"][::10],
            "volume": AAPL["volume"][::10],
            "extra_data": list(range(len(AAPL["volume"][::10]))),
        }
    )

    p = figure(
        plot_height=250,
        x_axis_type="datetime",
        tools="pan,wheel_zoom,box_zoom,reset,save",
        toolbar_location="below",
        title="AAPL price with Tooltip",
        sizing_mode="scale_width",
        output_backend="svg",
    )
    p.toolbar.logo = None
    p.background_fill_color = "#f5f5f5"
    p.grid.grid_line_color = "white"
    p.xaxis.axis_label = "Date"
    p.yaxis.axis_label = "Price"
    p.axis.axis_line_color = None

    p.line(x="date", y="adj close", line_width=2, color="#ebbd5b", source=source)

    p.add_tools(
        HoverTool(
            tooltips=[
                # use @{ } for field names with spaces
                ("date", "@date{%F}"),
                ("close", "$@{adj close}{%0.2f}"),
                ("volume", "@volume{0.00 a}"),
                ("extra_data", "@extra_data"),
                ("extra_note", "just any value"),
            ],
            formatters={
                "@date": "datetime",  # use 'datetime' formatter for 'date' field
                "@{adj close}": "printf",  # use 'printf' formatter for 'adj close' field
                # use default 'numeral' formatter for other fields
            },
            # display a tooltip whenever the cursor is vertically in line with a glyph
            mode="vline",
        )
    )

    if viz_type == "web":
        # Make the outputfile the same name as this script
        filename = Path(__file__).stem + ".html"
        output_file(filename)
        show(p)
    elif viz_type == "json":
        # Make the outputfile the same name as this script
        filename = Path(__file__).stem + ".json"
        with open(filename, "w") as json_file:
            div_id = "example_plot_With_hover"
            json.dump(json_item(p, div_id), json_file)
    else:
        print("Unsupported viz_type. What did you really want to say?")


if __name__ == "__main__":
    main()
    main(viz_type="json")