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2024


Modern pip build process (–use-pep517)

·3 mins

Nowadays, pyproject.toml becomes the standard configuration file for packaging. Compare with the old setup.py, it adds two feature pep517 and pep518.

pep517 defines two hooks: build_wheel and build_sdist, which is required to build the package from source. Each build backend must implement these two hooks. It makes it possible to create other build backend such as flit or poetry.

sys.path in Python

·3 mins

Here is the process how sys.path is set in Python, with some parts omitted.

Python Command Line Arguments #

By default, as initialized upon program startup, a potentially unsafe path is prepended to sys.path:

__import__ in Python

·2 mins

It’s known that Python’s import statement is implemented by __import__ function. In general, if we want to import a module dynamically, we can use import_module function, which is a wrapper around __import__.

The most important difference between these two functions is that import_module() returns the specified package or module (e.g. pkg.mod), while import() returns the top-level package or module (e.g. pkg). – https://docs.python.org/3/library/importlib.html#importlib.import_module

2023


iPod Video Review

·4 mins

I bought a iPod Video 5.5th Gen 80G recently. It’s only 200 Yuan (about $30) and I’m satisfied with it.

Rockbox #

The original firmware supports few audio format, it even can’t play FLAC. I install rockbox on it, which support FLAC and other format and I can transfer music without using iTunes or Finder. It also support theme and plugin, which makes it more powerful.

Improve Git speed in WSL

·2 mins

The disk performance in WSL2 is poor, it takes a long time to run git status in a host’s repo. Moreover, if you set a fancy shell prompt, it will take a long time to show the prompt. This article will introduce how to speed up Git in WSL2.

Line Ending in Git

·3 mins

When working on a project with multiple developers, the line ending can be troublesome. This article will explain how to configure line ending in Git.

Basic configuration #

The line ending on Windows is CRLF, on Linux is LF. To prevent the line ending issue, we can set core.autocrlf to true on Windows to let git convert CRLF to LF when commit, and convert LF to CRLF when checkout. It is automatically configured if you install git on Windows.

How to copy files temporarily in Dockerfile

·2 mins

It’s very common to copy a local file into the container when build docker image. In general, we use COPY command. But it creates a new layer and increase the final image size. If this is a temporal file and we don’t want users waste their storage space, how can we remove it? Here are some approaches.

2022


Memory Leak in Python multiprocessing.Pool

·4 mins

There is a historical memory leak problem in our Django app and I fixed it recently. As time goes by, the memory usage of app keeps growing and so does the CPU usage.

After some research, I figure out the cause. Some views does not close multiprocessing.Pool after using it. The problem disappears when I use Pool with with statement.

Emacs Chinese-related Settings

·1 min

Auto Switch Input Method in Evil #

This setting makes it possible to switch input method based on the context of cursor when entering insert mode.

sis #

I’m using sis package with this configuration. You may need to install macism if you’re not using railwaycat/emacsmacport. More settings can be found in emacs-smart-input-source.