告诉后台进程等待 matplotlib IPython 小部件完成绘制

如何解决告诉后台进程等待 matplotlib IPython 小部件完成绘制

我想在 Jupyter 中创建一个带有开始和停止按钮的动态 matplotlib 小部件。

以下代码有效，但只是因为调度程序被告知在继续下一步之前等待一秒钟。如果这个时间减少，matplotlib 图形迟早会崩溃。有没有办法等到matplotlib完成绘制？

%matplotlib widget

import numpy as np
import random as rd
import sched,time

from ipywidgets import widgets
from IPython.display import display
from IPython.lib import backgroundjobs as bg

jobs = bg.BackgroundJobManager()
s = sched.scheduler(time.time,time.sleep)

do_run_tick_func = False
x = [0]
    
def tick_func(sc):
    global x,ax,fig
    if do_run_tick_func:
        x.append(x[-1]+rd.random()-0.5)
        ax.clear()
        ax.plot(x)
        fig.canvas.draw()
        # TELL PYTHON TO WAIT UNTIL DRAW() IS DONE
        s.enter(1,1,tick_func,(sc,))

button_start = widgets.Button(description="Start")
button_stop = widgets.Button(description="Stop")

def on_button_start_clicked(b):
    global do_run_tick_func
    do_run_tick_func = True
    s.enterabs(time.time()+1,(s,))
    jobs.new(s.run)
    
def on_button_stop_clicked(b):
    global do_run_tick_func
    do_run_tick_func = False

button_start.on_click(on_button_start_clicked)
button_stop.on_click(on_button_stop_clicked)

myhBox = widgets.HBox([button_start,button_stop])
fig,ax = plt.subplots()
display(myhBox)

附注：

• 以上代码改编自以下讨论：Jupyter and timer functions?
• 如果有人知道如何避免全局语句，请告诉我！