As you probably saw in Chapter 15 and Chapter 16, you'll need to add a line each time you make a chart in order to render tooltips correctly:
chart = pygal.Bar() chart.force_uri_protocol = 'http'
chart = pygal.Bar(style=my_style, x_label_rotation=45, show_legend=False) chart.force_uri_protocol = 'http'
chart = pygal.Bar(style=my_style, x_label_rotation=45, show_legend=False) chart.force_uri_protocol = 'http'