Describe the bug

The to_js_literal method is taking excessively long time.

Steps Reproduce

1. First, let us create a 4000 points dataset.

import seaborn as sns original_df = sns.load_dataset('iris') df = sns.load_dataset('iris') for i in range(26): df = df.append(original_df, ignore_index=True) df

2. Now, create a Highcharts Python chart.

from highcharts_core.chart import Chart from highcharts_core.options.series.scatter import ScatterSeries from highcharts_core.options.plot_options import PlotOptions ch = Chart.from_pandas( df, property_map={ 'x': 'petal_width', 'y': 'sepal_length', }, series_type='scatter', ) # Disable boost. ch.options.plot_options = PlotOptions(series=ScatterSeries(turbo_threshold=0))

3. Then, when chart is displayed. the bulk of time goes in to_js_literal method. This particular method takes 21 seconds - See python profiling screenshot.

display(ch)

Expected behavior

I observed that:

1. IF the number of rows in the input DataFrame decreases, so does the time taken by to_js_literal method.
2. Why is this method taking so much time? I looked at the code - it seems that this is a recursive method. Due to this method taking 21 seconds, entire rendering time is 28 seconds. This is not a great user experience that you've to wait for half-a-minute to view your chart.

Your Environment

• OS: Windows, Jupyter Lab (notebook).
• Python Version: 3.10.4
• Highcharts Version: Installed Highcharts Python using pip install highcharts-core command.