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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():

Increasing the swapfile for Linux

hfwang132@gmail.com (hfwang132) — Mon, 12 Jun 2023 22:59:26 +0800

Xilinx’s toolchain consumes soooo much memory! Sometimes it causes the system to freeze… After all, my laptop only has 8GB of RAM. So there’s no other choice but to add virtual memories.

After increase the swapfile, the system performance has improved a lot:

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sudo swapoff /swapfile
sudo dd if=/dev/zero of=/swapfile bs=1M count=16384
sudo mkswap /swapfile
sudo swapon /swapfile

Mounting the EFI partition in Windows OS

hfwang132@gmail.com (hfwang132) — Mon, 12 Jun 2023 22:26:16 +0800

To mount the EFI partitions, run the following commands in PowerShell:

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diskpart
list disk # make sure which is the disk that contains the EFI partition. usually 0
select disk 0
list partition # make sure which is the EFI partition. normally 0
select disk 0
assign letter=z

Then we will mount the EFI partition as drive Z.

This operation may be useful when using a dual-boot system with Windows and Ubuntu: Sometimes, after removing the Ubuntu system, only the Windows system remains, but the GRUB interface still appears every time the computer boots. In this case, you need to delete the old Ubuntu EFI partition.