lightweight-charts-python/docs/source/examples/toolbox.md

Toolbox with persistent drawings

To get started, create a file called drawings.json, which should contain:

{}

---

import pandas as pd
from lightweight_charts import Chart


def get_bar_data(symbol, timeframe):
    if symbol not in ('AAPL', 'GOOGL', 'TSLA'):
        print(f'No data for "{symbol}"')
        return pd.DataFrame()
    return pd.read_csv(f'bar_data/{symbol}_{timeframe}.csv')


def on_search(chart, searched_string):
    new_data = get_bar_data(searched_string, chart.topbar['timeframe'].value)
    if new_data.empty:
        return
    chart.topbar['symbol'].set(searched_string)
    chart.set(new_data)
    
    # Load the drawings saved under the symbol.
    chart.toolbox.load_drawings(searched_string)


def on_timeframe_selection(chart):
    new_data = get_bar_data(chart.topbar['symbol'].value, chart.topbar['timeframe'].value)
    if new_data.empty:
        return
    # The symbol has not changed, so we want to re-render the drawings.
    chart.set(new_data, keep_drawings=True)


if __name__ == '__main__':
    chart = Chart(toolbox=True)
    chart.legend(True)

    chart.events.search += on_search
    chart.topbar.textbox('symbol', 'TSLA')
    chart.topbar.switcher(
        'timeframe',
        ('1min', '5min', '30min'),
        default='5min',
        func=on_timeframe_selection
    )

    df = get_bar_data('TSLA', '5min')

    chart.set(df)

    # Imports the drawings saved in the JSON file.
    chart.toolbox.import_drawings('drawings.json')
    
    # Loads the drawings under the default symbol.
    chart.toolbox.load_drawings(chart.topbar['symbol'].value)  
    
    # Saves drawings based on the symbol.
    chart.toolbox.save_drawings_under(chart.topbar['symbol'])  

    chart.show(block=True)
    
    # Exports the drawings to the JSON file upon close.
    chart.toolbox.export_drawings('drawings.json')