Posts about python (old posts, page 40)

2012-07-10 21:34

Programando Cross-Platform

Sorry again, spanish only, because it's another video of me speaking in spanish (this time with a spaniard)

Si querés tener muchos usuarios de tu programa, es fundamental que el universo de "gente que puede usar el programa" sea lo más grande posible. El mejor camino para ello es hacer que el sistema operativo que usa/sufre tu potencial usuario esté soportado. Hacer eso no es increíblemente difícil, pero siempre hay alguna cosa rara. La conferencia tuvo lugar en la ciudad de Junín ( Buenos Aires, Argentina ) en Septiembre de 2011, y fué organizada por PyAr ( Python Argentina ).



2012-07-10 09:40

Haciendo trampa: Trucos para programar menos

Sorry, spanish only, since it's a video of me speaking in spanish ;-)

Finalmente, gracias a Juan Rodriguez Monti, video de mi charla "Haciendo trampa: Trucos para programar menos" de PyCon Argentina 2011.

Y los slides:

2012-07-09 11:44

PyCamp Panorama

So you couldn't make it to PyCamp? This is the place. Sorry, I can't post the awesome, so it's just a picture :-)

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2012-07-09 11:18

Nikola-as-a-service demo

One of the things I hacked at during this PyCamp is trying to figure out a nice workflow for Nikola, something that will enable users that are not so technical, to use it.

One first step is Nikola-as-a-service, which is meant for technical users anyway but lays down the infrastructure for this to work semi-nicely.

In the video below, you will see me do this:

  • Go to GitHub
  • Take a starter's blog I provided, and do a clone
  • Go to the nikola-as-a-service site, and login (via twitter)
  • Create a site using my fork's repo URL
  • Get a "webhook" URL, and add it to my fork's admin as a post-commit hook
  • Edit a file in github's web UI and commit it (you can of course just push from any github client)
  • Automatically, the site nikola-as-a-service publishes gets updated.

Please don't try to use this service yet because:

  1. It's running in a $4.50/month server
  2. It's the same server my own blog uses
  3. I will turn it off, delete everything, etc. every once in a while
  4. I am editing the code on the server, so no guarantees it will not just stop working.

So, here's the video:

2012-07-09 01:45

PyCamp 2012 - Day 3

So, day 3 and next-to-last of PyCamp is done.

  • Great day, sunny, not all that cold
  • Empanadas at lunch, pizza for dinner, cake for tea. Feeling kinda spoiled today.
  • Lots of hacking at Nikola-as-a-service (details below)
  • PyAr meeting by a huge, somewhat scary bonfire earlier tonight

So: Nikola-as-a-service is an idea where you can keep your blog somewhere, and this service will get the data, and publish a nice site for you.

Here's the current workflow, which is just one of a dozen that can be implemented because this thing is quite simple:

  1. The authenticator

    Currently it has twitter authentication. You never need to create an account, just login with some service you already have accounts with. Anything with OAuth will work.

  2. The data provider

    Currently, github. Soon, Ubuntu One. Later, who knows. A data provider is something from where we can grab data, and that can notify us (automatically or by having the user click on a button) when we should get that data and rebuild the site.

  3. The renderer

    I am doing it with Nikola, of course :-)

  4. The infrastructure

    Jobs using Redis and Celery, server app using Flask, rendering using Nikola

  5. How does it work?

    You go to github, clone a barebones blog. Do your modifications. Go to nikola-as-a-service, and login via something. Then you give Nikola your github repo's URL, and you get a webhook URL. Go back to github, and configure the webhook.

    From that moment on, every time you push to github, your blog is updated :-)

    In the future: every time you save to Ubuntu One, your blog is updated. In the further future: Every time you X to Y, your blog is updated.

It's going to be cool :-)

2012-07-08 00:22

PyCamp 2012: Day 2

Finishing Day 2, here's the update.

That is one large spider, dude.

  • Woke up 10 time because David Litvak doesn't know how to turn off his alarm. Now hating "Good Day Sunshine" by The Beatles. Sorry Ringo!
  • Learned about Celery/Flask/Juggernaut. Tomorrow will try to hack on the Nikola server idea using that. Hugo Ruscitti already did a lot of work!
  • Helped Martín Gaitán do Nikola gallery improvements (looking much nicer now!)
  • Implemented code listings for Nikola
  • Had a huge spider walk up my leg.
  • Had asado for dinner!
  • Played with remote controlled cars.
  • Saw a guy juggle while riding a monocycle
  • Played in the ping pong tournament (record 1-1, out in the group phase)
  • Fixed a bunch of bugs that popped while implementing stuff.

Tomorrow: will hack all day in the nikola hosting idea.

2012-07-07 23:51

New Nikola Feature: code listings

This is a new feature in Nikola, my static website and blog generator.

It's aimed at showing pieces of files in the posts, and giving you a link to the full file, does reasonable syntax highlight thanks to pygments, and the syntax for embedding in your posts is not excessively awful, so I can use it for some of my tutorial / book projects.

Here's an example:

.. listing:: python
   :start-at: def compile_html
   :end-before: output =

System Message: ERROR/3 (<string>, line 14)

Error in "listing" directive: unknown option: "start-at".

.. listing:: python
    :start-at: def compile_html
    :end-before: output =

This is not merged into master yet, but should be soon.

2012-07-06 23:54

PyCamp Day 1

Going to sleep, so here's a quick rundown of my 1st day at Pycamp:

  • Woke up at 6AM, and after taking trains, buses and automobiles, arrived around noon. Place is nice, wheather is cold. Beds are bunks.
  • Presented ideas, voted working slots
  • Implemented a Nikola feature to get themes from
  • Implemented first draft of pipelines for post-processing generated files
  • Martín Gaitán is working on improving the image galleries
  • Hugo Ruscitti is doing some celery+flask magic to create a Nikola hosting service
  • Had fun with lots of other things and talking with a lot of people.
  • Played some table tennis (won 1, lost 1)
  • Got a firefox t-shirt
  • Got a Ninja-IDE mug that changes colour with temperature.

Now, exhausted, going to bed.

2012-07-04 22:28

Nikola Ideas for PyCamp

This friday is the beginning of PyCamp, four days of python hacking without distraction or pause. And I want to code a lot. My main target is features for Nikola my static blog generator.

If you are attending PyCamp (or even if you are not), you are welcome to join me in implementing these in a marathon of kickass coding starting this friday and lasting all weekend.

I have a few ideas in my head, but I want more. These are the ones I have, please add more in the comments if you have any:

Code Gallery
Like image galleries but for code. Put code in a folder and it will be beautifully displayed. With the addition of a "listings" docutils directive, it will make showing code in detail and in context easy and powerful, and make Nikola more attractive to programmer-bloggers.
Gallery Polishing
Image galleries are implemented and work, but they could use a lot of polish. From making them more network-efficient, to image RSS feeds, recursive galleries, gallery metadata, image texts, and much more.
File Pipelines

Want to minimize your CSS? Tidy your HTML? pngcrush your images? apply HTML transformations? Other things I can't imagine?

File pipelines would bring the power of the unix shell to a site generator, letting you connect lego-like filters, some provided, some from the community, into a powerful machinery.

Online Editing (Alva)
While static site generators have lots of benefits, they have one significant downside: you edit the files in your own device. A online editor for Nikola lets you edit them through a web interface for blogging-from-aywhere goodness.
Nikola Hosting (Shoreham)
Why not create a service where the user feeds posts to a server and then the server publishes them? The feeding can be via a DVCS, or a file sync service, or via online editors, and the output is published automatically or at the push of a button.
I don't do drafts. I type and that's it. But others prefer more cautious and sane approaches. So, how should drafts work? While the feature may be easy to implement, it's a good beginner programmer's task, where you have to think more about what you want to achieve and providing a good user experience than about just banging code.

So, is there something you saw in another static blog generator and Nikola lacks? Any cool ideas and want a friendly codebase to hack them on? Do you have any crazy ideas noone would touch with a ten-foot-pole but you think would be awesome to have?

Well, now's a good time to talk about it!

2012-07-03 21:46

Python is Not a Configuration File Format

There is a large thread in reddit about using Python as configuration file format. I want to be clear about that:


If you need to ask if it's a good idea, then you don't have a good reason. If you are sure that you have a good reason, then maybe you have a good reason.

There are many reasons for it, but I will explore just two, then offer a suggestion.

Python is read-only, and configuring is not programming.

Sure, it's easy to use python as a config file. You just import the thing, and there you go, all the data is there. But now your configuration syntax is a general purpose language that can do things like pop up dialogs when you parse it.

Your config can now depend on the whole internet, the hardware, the weather, and interactive input. Powerful? Sure. Good idea? Maybe, sometimes. But your application is now not able to configure itself.

If your application wants to store any kind of setting, it won't be able to. So most interactive, desktop apps, just should not use python for this, ever.

But what about non-interactive tools? Well, using python means that other tools can't write to the config file, either, which makes the tool less powerful. The power to have tools use tools is one of the cornerstones of modern computing, and you just cut your app off that ecosystem. Depending on what language the tool uses it may not even be able to parse your config file.

And what happens when someone is told "use this config fragment to achieve X"? Well, odds are, if the recipient has done anything that takes advantage of using python as a config format, then the fragment will not work. It would be like doing copy/paste from random code in github into your own program and expecting it to work.

So, you can't write to it from the app, you can't get configuration tips from the internet, you can't use other tools to modify config files, and other tools have a hard time parsing your files.

Also, it means that to handle the general case of configuring your app, you need a programmer. That is almost certainly overkill. Very few apps need that kind of thing. If your app can only be configured by programmers, you may have failed at making a good app (exceptions exist).

And what's the advice? Well, the advice is "don't do that" and the corollary is "configure using data, not code". use INIs, or XML, or YAML, or JSON, or plain text files, or whatever. But not code.

PS: My latest project, Nikola uses python as a configuration language. I thought I had a good reason. I didn't.

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