Polling Jupyter widget UI events in runtime

hfwang132@gmail.com (hfwang132) — Sat, 01 Jul 2023 17:48:54 +0800

Let’s look at a code snippet in the Jupyter Notebook:

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import time
import ipywidgets as widgets
from IPython.display import display

slider = widgets.IntSlider()
display(slider)

while True:
 print(slider.value)
 time.sleep(1)

IntSlider is an interactive Jupyter Notebook widget. When the user interacts with the slider, the slider value should change.

However, if you run the above codes, you will find that the printed value of the slider won’t change at all – it will be stuck at its initial value.

Python coroutines and asyncio

hfwang132@gmail.com (hfwang132) — Tue, 13 Jun 2023 22:05:41 +0800

Recently, I have been using Python coroutines/asynchronous programming in a project. Now, I will summarize my experience.

Import

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import asyncio

If asyncio is to be used in an IPython environment, we have to add two more lines：

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import nest_asyncio
nest_asyncio.apply()
import asyncio

Coroutines

Coroutines are the core of asynchronous programming in Python. To define a coroutine, you need to use async def.

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async def main():
 # do something
 print("Hello world!")

To execute the coroutine, you cannot directly call main(). Instead, you need to use run():

Python on Haifei's Home

Polling Jupyter widget UI events in runtime

Python coroutines and asyncio

Import

Coroutines