def test_barchart_with_generator():
    import cartesius.colors as colors

    coordinate_system = cartesius.CoordinateSystem()

    bottom_collor = (0, 0, 255)
    top_color = (255, 255, 255)

    # In case you don't want to keep all your data in memory, you can give the data as a
    # generator function that will lazy-load your data. This works for all charts:
    def data_generator():
        for x in range(25):
            key = x / 2.
            value = 2 * math.sin(x/4.)
            color = colors.get_color_between(bottom_collor, top_color, (value + 2) / 4.)
            yield charts.data(key, value, fill_color=color)

    barchart_data_generator = data_generator
    barchart = charts.BarChart(data=barchart_data_generator, vertical=True, width=0.5)
    coordinate_system.add(barchart)

    return coordinate_system.draw(300, 200), coordinate_system.draw(300, 200, antialiasing=True),
traverse and visit the given expression structure using the default
dataset/ETHPy150Open tkrajina/cartesius/create_images_and_readme.py/test_barchart_with_generator--crossover with--dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/sql/visitors.py/traverse