Plot simple map with Prague and

plot_world_covid.py

from bokeh.plotting import figure, show, output_notebook
from bokeh.models import HoverTool
from bokeh.tile_providers import Vendors, get_provider

import pandas as pd

def web_mercator(long, lat):
    import numpy as np
    scale_x = 4e7 / 360
    limit_lat = 2 * np.arctan(np.exp(np.pi)) - np.pi / 2
    scale_y = 2e7 / np.log(np.tan(np.pi / 4 + limit_lat / 2))
    
    x = scale_x * long
    lat_rad = np.pi / 180 * lat
    y = scale_y * (np.log(np.tan(np.pi / 4 + lat_rad / 2)) )
    return x, y

data = pd.DataFrame(
    [
        ("Prague", 50, 14.5, 50),
        ("Wuhan", 30.5, 114.25, 50000)
    ], columns=["name", "lat", "long", "cases"]
)
web_mercator_coords = web_mercator(data["long"], data["lat"])
data = data.assign(
    wx=web_mercator_coords[0],
    wy=web_mercator_coords[1],
    radius = np.log(data["cases"]) * 100000
)

output_notebook()

tile_provider = get_provider(Vendors.CARTODBPOSITRON)

tools = 'hover,box_zoom,pan,save,reset,wheel_zoom'

p = figure(x_range=(-18000000, 18000000), y_range=(-4000000, 7000000),
           x_axis_type="linear", y_axis_type="linear", tools=tools)
p.add_tile(tile_provider)
p.circle(x="wx", y="wy", radius="radius", alpha=0.5, source=data)

hover = p.select(dict(type=HoverTool))
hover.tooltips = [("Place", "@name"), ("Cases", "@cases"),]
hover.mode = 'mouse'

show(p)