python - 如何从选择 Bokeh 更改数据源

Question

我正在使用 Bokeh 和 Python 2.7

我正在尝试更新数据源以更改基于选择框的绘图。但我无法更新剧情。我究竟做错了什么？或者有更好的方法吗？

代码:

from bokeh.models import ColumnDataSource
from bokeh.plotting import figure, output_file, show, output_notebook
from bokeh.models.widgets import Select
from bokeh.io import curdoc
from bokeh.layouts import column, row
from bokeh.io import output_file, show
from bokeh import models
import pandas as pd

d1 = dict(x=  [10,4,6,4], y =  [6,2,8,10])

d2 = dict(x=  [23,12,50,30], y =  [5,10,23,18,12])

source = ColumnDataSource(data=d1)

p = figure()

select = Select(title="Select d",  options=['d1', 'd2'])

def update_plot(attrname, old, new):
    if new == 'd1':
        newSource = d1

    if new == 'd2':
        newSource = d2


    source.data =  newSource

p.line(x='x', y='y',source = source)

select.on_change('value', update_plot)
layout = column(row(select, width=400), p)
curdoc().add_root(layout)
show(layout)

Answer 1

您需要使用 Bokeh 服务器启动 Bokeh ，如下所示:

bokeh serve myscript.py

然后在浏览器中打开localhost:5006。

如果您在没有服务器的情况下启动 Bokeh ，那么它只会创建一个静态 html 文件，并且您无法让页面调用您的函数(这就是为什么您看不到 print )或在初始加载后使用 python 代码更改页面。来自 the docs :

The architecture of Bokeh is such that high-level “model objects” (representing things like plots, ranges, axes, glyphs, etc.) are created in Python, and then converted to a JSON format that is consumed by the client library, BokehJS. [...] However, if it were possible to keep the “model objects” in python and in the browser in sync with one another, then more [you could also] respond to UI and tool events generated in a browser with computations or queries using the full power of python