import asyncio
import perspective
import random
import datetime

async def update(table):
    while True:
        now = datetime.datetime.now()
        data = [{"value": 1, "label": "L1", "timestamp": now}]
        for label in ("L1", "L2", "L3"):
            val = random.random()
            if val > 0.9:
                data.append({"value": val, "label": label, "timestamp": now})
        table.update(data)
        await asyncio.sleep(0.1)
        

schema = {
    "timestamp": datetime.datetime,
    'value': float,
    'label': str,
}

table = perspective.Table(schema, limit=10)
widget = perspective.PerspectiveWidget(table,  column_pivots=['label'], plugin="X/Y Scatter")
asyncio.get_event_loop().create_task(update(table))
widget # show