Python

A collection of 67 posts

Python

Scaling a polling Python application with parallelism

A few weeks ago, Alon contacted me and asked me the following: > It so happened that I'm currently working on scaling some Python app. Specifically, now I'm trying to figure out the best way to scale SSH connections - when one server has to connect to thousands (or even tens

Books

Scaling Python released

I am proud to announce today the immediate release of Scaling Python [https://scaling-python.com], my second book about Python! It talks about the distribution and performance of applications written in Python, and how to build them properly! It took me a year to build this entirely new product around

Books

Scaling Python: the interviewees

The release date for Scaling Python [http://scaling-python.com] is now very close! Today, I'd like to talk a bit about the interviews that I've run those last months that are featured in the book. I'm glad that during those long weeks work, I have managed to find a Python

Interview

My interview with Cool Python Codes

A few days ago, I've recently been contacted by Godson Rapture from Cool Python codes [http://coolpythoncodes.com/] to answer a few questions about what I work on in open source. Godson regularly interview developers and I invite you to check out his website! Here's a copy of my original

Talks

Attending PyCon FR 2017

The French edition of the annual Python conference, PyCon FR [https://pycon.fr/2017/], will happen in Toulouse from 21st to 24th September. I skipped the last few PyCon FR, but this year I will be back with a one-hour long talk entitled "Scalable and distributed applications in Python". It

Python

Easy Python logging with daiquiri

After more than 10 years of writing Python, there's something I always have been annoyed with: logging. Don't read me wrong: I like the Python logging subsystem [https://docs.python.org/3/library/logging.html]. It's easy to use and works like a charm in most cases. If you never

Python

Python never gives up: the tenacity library

A couple of years ago, I wrote about the Python retrying library [https://julien.danjou.info/python-retrying]. This library was designed to retry the execution of a task when a failure occurred. I started to spread usage of this library in various projects, such as Gnocchi [http://gnocchi.xyz], these

Talks

FOSDEM 2017, recap

Last week-end, I was in Brussels, Belgium for the 2017 edition of the FOSDEM [http://fosdem.org], one of the greatest open source developer conference. This year, I decided to propose a talk about Gnocchi [http://gnocchi.xyz] which was accepted in the Python devroom [https://fosdem.org/2017/schedule/

Books

Scaling Python is on its way

My day-to-day activities are still evolving around the Python [http://python.org] programming language, as I continue working on the OpenStack [http://openstack.org] project as part of my job at Red Hat [http://redhat.com]. OpenStack is still the biggest Python project out there, and attract a lot of

Python

Packaging Python software with pbr

Packaging Python has been a painful experience for long. The history of the various distribution that Python offered along the years is really bumpy, and both the user and developer experience has been pretty bad. Fortunately, things improved a lot in the recent years, with the reconciliation of setuptools [https:

Python

From decimal to timestamp with MySQL

When working with timestamps, one question that often arises is the precision of those timestamps. Most software is good enough with a precision up to the second, and that's easy. But in some cases, like working on metering, a finer precision is required. I don't know exactly why, and it

Python

The definitive guide to Python exceptions

Three years after my definitive guide on Python classic, static, class and abstract methods [https://julien.danjou.info/guide-python-static-class-abstract-methods], it seems to be time for a new one. Here, I would like to dissect and discuss Python exceptions [https://docs.python.org/3/tutorial/errors.html]. Dissecting the base exceptions

Books

The Hacker's Guide to Python 3rd edition is out

Exactly a year ago, I released the second edition of my book The Hacker's Guide to Python [https://julien.danjou.info/the-hacker-guide-to-python-second-edition]. One more time, it has been a wonderful release and I received a lot of amazing feedback from my readers all over this year. Since then, the book

Pifpaf

Pifpaf, or how to run any daemon briefly

There's a lot of situation where you end up needing a software deployed temporarily. This can happen when testing something manually, when running a script or when launching a test suite. Indeed, many applications need to use and interconnect with external software: a RDBMS (PostgreSQL [http://postgressql.org], MySQL [http:

Gnocchi

Timeseries storage and data compression

The first major version of the scalable timeserie database I work on, Gnocchi [http://gnocchi.xyz] was a released a few months ago. In this first iteration, it took a rather naive approach to data storage. We had little ideas about if and how our distributed back-ends were going to

Python

Profiling Python using cProfile: a concrete case

Writing programs is fun, but making them fast can be a pain. Python programs are no exception to that, but the basic profiling toolchain is actually not that complicated to use. Here, I would like to show you how you can quickly profile and analyze your Python code to find

Interview

My interview in le Journal du Hacker

A few days ago, the French equivalent of Hacker News [https://news.ycombinator.com/], called "Le Journal du Hacker [https://www.journalduhacker.net/]", interviewed me [https://www.journalduhacker.net/s/l5qktw/journal_du_hacker_entretien_avec_julien_danjou_d_veloppeur_openstack] about my work on OpenStack [http://openstack.org], my

Python

Data validation in Python with voluptuous

Continuing my post series on the tools I use these days in Python, this time I would like to talk about a library I really like, named voluptuous [https://pypi.python.org/pypi/voluptuous]. It's no secret that most of the time, when a program receives data from the outside,

LWN.net

Reading LWN.net with Pocket

I've started to use Pocket [https://pocket.co] a few months ago to store my backlog of things to read. It's especially useful as I can use it to read content offline since we still don't have any Internet access in places such as airplanes or the Paris metro. It's

Python

Timezones and Python

Recently, I've been fighting with the never ending issue of timezones. I never thought I would have plunged into this rabbit hole, but hacking on OpenStack and Gnocchi I felt into that trap easily is, thanks to Python. “Why you really, really, should never ever deal with timezones” To get

Python

Get back up and try again: retrying in Python

The library presented in this article is becoming obsolete and un-maintained. I recommend you to read this post about tenacity [https://julien.danjou.info/python-tenacity] instead. I don't often write about tools I use when for my daily software development tasks. I recently realized that I really should start to

Interview

My interview about software tests and Python

I've recently been contacted by Johannes Hubertz [http://hubertz.de/blog/], who is writing a new book about Python in German called "Softwaretests mit Python" which will be published by Open Source Press, Munich this summer. His book will feature some interviews, and he was kind enough to let me

Books

The Hacker's Guide to Python, 2nd edition!

A year passed since the first release of The Hacker's Guide to Python [https://julien.danjou.info/blog/2014/the-hacker-guide-to-python-has-been-released] in March 2014. A few hundreds copies have been distributed so far, and the feedback is wonderful! I already wrote extensively about the making of that book [https://julien.danjou.

Python

Hacking Python AST: checking methods declaration

A few months ago, I wrote the definitive guide about Python method declaration [guide-python-static-class-abstract-methods], which had quite a good success. I still fight every day in OpenStack [http://openstack.org] to have the developers declare their methods correctly in the patches they submit. Automation plan The thing is, I really

Python

Distributed group management and locking in Python with tooz

With OpenStack [http://openstack.org] embracing the Tooz [http://launchpad.net/python-tooz] library more and more over the past year, I think it's a good start to write a bit about it. A bit of history A little more than year ago, with my colleague Yassine Lamgarchal and others at