Recently, there is a GitHub issue about namespace package in Azure CLI. I think it is a good time to write down the knowledge about namespace package.
If several packages share the same root folder, then the root folder is a namespace package. subpackageA and subpackageb can be installed separately, even in different Python path, but they can be imported as importing a single package: import root.
Three years ago, I bought a QNAP TS-453Dmini NAS. Although it has a slow WEB UI and slow restart, it still fits my needs as all of the applications I need are running in Docker.
Recently, I want to move some files from my Mac to NAS to save space. I need a application behave like Dropbox, which can show all the files in the NAS and only download the files I need. I have tried the QSync, but it does not have thumbnails for cloud image and it does not have icons to show the file status. I also tried the Seafile, it’s a powerful application, which requires 4G RAM to run, and there is bug in the thumbnail. I used to have a Synology ARM NAS, the Synology Drive has all the features I need, so I want to run it on my QNAP NAS. After some research, I managed to run Synology and QNAP together on my NAS. Here is the guide.
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.
[build-system]
# Defined by PEP 518:
requires = ["flit"]
# Defined by this PEP:
build-backend = "local_backend"
backend-path = ["backend"]
Besides setuptools, there are some other build back-end such as hatchling and flit. You can find the example here: Python Packaging Uer Guide - Choosing a build backend
Here is the process how sys.path is set in Python, with some parts omitted.
By default, as initialized upon program startup, a potentially unsafe path is prepended to sys.path:
python -m: prepend the current working directory.
python script.py: prepend the script’s directory. If it’s a symbolic link, resolve symbolic links.
python -c and python (REPL): prepend an empty string, which means the current working directory.
You can remove these path with -P param.
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
import itertools and from requests import exceptions can be translated to:
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.
The performance of file system in WSL2 is poor, it takes a long time to run git status in a host’s repo. The solution is to use git.exe in Windows folder. You can add this into your bashrc: