Created
April 4, 2020 19:02
-
-
Save bendichter/ef185a1fb4784e12da74a964a63c898a to your computer and use it in GitHub Desktop.
Example of how to thread a plotting widget so that only the latest command is run
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
from ipywidgets import VBox, Button, HTML | |
import time | |
from threading import Thread | |
from queue import Queue | |
class MyWidget(VBox): | |
def __init__(self): | |
super(MyWidget, self).__init__() | |
self.button = Button(description='next') | |
self.out = HTML('start') | |
self.button.on_click(self.handler) | |
self.children = [self.button, self.out] | |
self.count = 0 | |
self.plotting_thread = None | |
self.queue = Queue(maxsize=1) | |
self.plotting_thread = Thread(target=self.plotter) | |
self.plotting_thread.daemon = True | |
self.plotting_thread.start() | |
self.command_counter = 0 | |
def plotter(self): | |
while True: | |
command_counter = self.queue.get() | |
self.move_up() | |
print('command: {}'.format(command_counter)) | |
self.queue.task_done() | |
def move_up(self): | |
time.sleep(5) | |
self.count += 1 | |
self.out.value = str(self.count) | |
def handler(self, change): | |
self.command_counter += 1 | |
if self.queue.full(): | |
self.queue.get() | |
self.queue.task_done() | |
self.queue.put(self.command_counter) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
To test, run this in a notebook. Then click "next" a bunch of times in a row. The code should only execute twice- the firs time and the last time the button is pressed (as indicated by the command count).