import panel as pn

from streamz import Stream

pn.extension('vega')

def increment(x):
    return x + 1

source = Stream()

streamz_pane = pn.pane.Streamz(source.map(increment), always_watch=True)

# Note: To ensure that a static render of the stream displays anything
#       we set always_watch=True and emit an event before displaying
source.emit(1)

streamz_pane

count = 1 

def emit_count():
    global count
    count += 1
    source.emit(count)

pn.state.add_periodic_callback(emit_count, period=100);

import numpy as np
import altair as alt
import pandas as pd
from datetime import datetime
from streamz.dataframe import DataFrame as sDataFrame

df = sDataFrame(example=pd.DataFrame({'y': []}, index=pd.DatetimeIndex([])))

def line_plot(data):
    return alt.Chart(pd.concat(data).reset_index()).mark_line().encode(
        x='index',
        y='y',
    )

altair_stream = df.cumsum().stream.sliding_window(50).map(line_plot)

altair_pane = pn.pane.Streamz(altair_stream, height=350, always_watch=True)

for i in range(100):
    df.emit(pd.DataFrame({'y': [np.random.randn()]}, index=pd.DatetimeIndex([datetime.now()])))

altair_pane

def emit():
    df.emit(pd.DataFrame({'y': [np.random.randn()]}, index=pd.DatetimeIndex([datetime.now()])))

pn.state.add_periodic_callback(emit, period=100);