Today’s blog post is going to contain fairly advanced Python hackery. We’ll
take two functions — one is a wrapper for the other, but also adds some
positional arguments. And we’ll change the signature displayed everywhere from
the uninformative f(new_arg, *args, **kwargs) to something more
appropriate.
In Python, virtual environments are used to isolate projects from each other (if they require different versions of the same library, for example). They let you install and manage packages without administrative privileges, and without conflicting with the system package manager. They also allow to quickly create an environment somewhere else with the same dependencies.
Virtual environments are a crucial tool for any Python developer. And at that, a very simple tool to work with.
Pipenv is a Python packaging tool that does one thing reasonably well — application dependency management. However, it is also plagued by issues, limitations and a break-neck development process. In the past, Pipenv’s promotional material was highly misleading as to its purpose and backers.
In this post, I will explore the problems with Pipenv. Was it really recommended by Python.org? Can everyone — or at least, the vast majority of people — benefit from it?
(This post has been updated in February 2020 and May 2020 to reflect the current state of Pipenv.)
As part of your code, you may be inclined to call a command to do something. But is it always a good idea? How to do it safely? What happens behind the scenes?
Gynvael Coldwind jest badaczem bezpieczeństwa pracującym w Google, który organizuje cotygodniowe livestreamy na tematy bezpieczeństwa i programowania po polsku i po angielsku). Częścią streamów są misje — w skrócie, zadania w stylu CTF-owym dotyczące inżynierii wstecznej. Wczorajsza misja była o elfickim — znaczy o Paint’cie — znaczy o programowaniu w Pythonie i jego bajtkodzie.
Setting up Python is usually simple, but there are some places where newcomers (and experienced users) need to be careful. What versions are there? What’s the difference between Python, CPython, Anaconda, PyPy? Those and many other questions may stump new developers, or people wanting to use Python.
You might get unusual errors about Unicode and inability to convert to ASCII. Programs might just crash at random. Those are often simple to fix — all you need is correct locale configuration.
To create a project that other people can use and contribute to, you need to follow a specific directory structure. Moreover, releasing a new version should be as simple and painless as possible. For my projects, I use a template that has the structure already in place, and comes with automation for almost every part of a release.
Recently I was working on some C# and Java code. And along the way, I used Python and Vim to (re)write my code. A small Python script and a 6-keystroke Vim macro did it faster and better than a human would.
Every programmer should learn a good scripting language and use a programmable editor like Vim. Why? Here are two examples, after the break.
You’ve just written a great Python web application. Now, you want to share it with the world. In order to do that, you need a server, and some software to do that for you.
The following is a comprehensive guide on how to accomplish that, on multiple Linux-based operating systems, using nginx and uWSGI Emperor. It doesn’t force you to use any specific web framework — Flask, Django, Pyramid, Bottle will all work. Written for Ubuntu, Debian, Fedora, CentOS 7 and Arch Linux (should be helpful for other systems, too). Now with an Ansible Playbook.
Revision 7c (2020-05-01): works with Ubuntu 20.04 and Fedora 32; previous Revision 7a (2020-02-03): Move virtual environment to separate venv folder to improve Python upgrades (venvs should be ephemeral); add Docker section