- bokeh
- numpy
- pandas
- panel
import asyncio
import panel as pn
import numpy as np
import pandas as pd
from bokeh.models import ColumnDataSource
from bokeh.plotting import figure
from panel.io.pyodide import show
df = pd.DataFrame(np.random.randn(10, 4), columns=list('ABCD')).cumsum()
rollover = pn.widgets.IntInput(name='Rollover', value=15)
follow = pn.widgets.Checkbox(name='Follow', value=True, align='end')
tabulator = pn.widgets.Tabulator(df, height=450, width=400)
def color_negative_red(val):
"""
Takes a scalar and returns a string with
the css property `'color: red'` for negative
strings, black otherwise.
"""
color = 'red' if val < 0 else 'green'
return 'color: %s' % color
tabulator.style.applymap(color_negative_red)
p = figure(height=450, width=600)
cds = ColumnDataSource(data=ColumnDataSource.from_df(df))
p.line('index', 'A', source=cds, line_color='red')
p.line('index', 'B', source=cds, line_color='green')
p.line('index', 'C', source=cds, line_color='blue')
p.line('index', 'D', source=cds, line_color='purple')
def stream():
data = df.iloc[-1] + np.random.randn(4)
tabulator.stream(data, rollover=rollover.value, follow=follow.value)
value = {k: [v] for k, v in tabulator.value.iloc[-1].to_dict().items()}
value['index'] = [tabulator.value.index[-1]]
cds.stream(value)
cb = pn.state.add_periodic_callback(stream, 200)
controls = pn.Row(cb.param.period, rollover, follow, width=400)
await show(controls, 'controls')
await show(tabulator, 'table')
await show(p, 'plot')