This post was written in(dd-mm-yyyy hh:mm) 27/10/2009 00:39 PM (-3 GMT)

I’ll try to put here a step-by-step of what you should do on your Windows XP machine  in order to install Eclipse to use it as a Python IDE.

DOWNLOADING

You’ll need the following – software to be downloaded and installed – in the exact order that follows beneath:

After you’re logged into your machine as an administrator you should download the softwares from 2-3.

Eclipse:

1. Extract and run Eclipse.
2. Go to the menu “Help” > “Find and Update” > “Find and Install…”.
3. Select the option “Search for new features to install” and click “Next”.
4. Click the button “New Remote Site” and fill the “Name:” field with the name PyDev and the “URL:” field with the following URL: http://pydev.org/updates
5. Click “Finish”.
6. Select the entire PyDev package or the packages you want “PyDev” and/or “PyDev Mylnyn Integration (optional)”.
7. Click “Next”.
8. “I accept the terms in the license agreements”.
9. Click “Next” and “Finish”.
10. After a while click “Install all”.
11. Eclipse will ask you if it’s ok to restart click “Yes”.

PyDev 1.5.0 will take ~21,96 Mb.

CONFIGURING THE INTERPRETER

Now you should do the following inside Eclipse:

1. Click in “Window” > “Preferences…” > “PyDev”.
2. Click in the option “Interpreter - Python” and click in the upper right button named “New”.
3. Click in the “Browse” button to search for your “python.exe” file and after that click “Ok” three times.

Done! If you did everything correctly you’ll have by now Python and Eclipse working together. For further information check the PyDev Documentation site. Enjoy!

Ever since I heard about plasma I was eager to find ways to write my own plasmoid. But for the development of binary plasmoids, it is necessary to compile at least a part of kde4, at least this is what I understood from the prerequisite listed on the official tutorial. This discouraged me a bit. Moreover, I think that installation of the binary gadgets also requires to either package them properly according to the distribution you want to distribute for or you need to provide the sources that requires the users to build them. This  in my opinion is really a huge overhead for small applications like desktop gadgets / widgets. Then I found that it is also possible to develop plasmoids with script languages like python, ruby and javascript.

Even though, I didn’t know PyQT4 or PyKDE4 libraries at all, I decided to write my first plasmoid in python.  This is an exremely simple plasmoid, the core of which was put together in a few hours on a rainy weekend. I have to admit that being a java developer, my code is not pythonic enough.

It can be downloaded from: kde-look.

Here the source code: plasma_pyweather.

The layout is based on my conky setup described here. I have tried to keep it as compact as possible including most of the provided information, if not all.  I don’t want the weather information to cover most of the screen.  The initial version of the plasmoid was written using the QT4 widgets, but was looking ugly.

The weather information is fetched from google weather api. The location and the unit are configurable. The api provides forecast only for the next 3 days, so the number of forecast days were not made configurable.  Some how for google weather api the locale and so the unit is connected to the language, therefor  I had to convert the units myself. To keep the display compact I rounded the temperatures to integers.

I got to learn PyQT4 and PyKDE4 libraries while writing this. Especially PyQT4 is a very powerful gui library for python.  It is fun programming with it. I have used eclipse + pydev for developing. In the beginning I didn’t have the auto-completion for PyQT4 as well as PyKDE4 in this environment, because they are not installed as pure python source code files. I could fix this with following answer.

The other interesting things, I learned was to use the qt-designer tool for creating gui. It is a nice WYSIWYG tool for designing complex guis. The configuration form is designed using this tool. The qt-designer creates a .ui file, which is an xml file. The .ui file can be converted to the python source code using the pyuic4 tool in the following way.

pyuic4 -o configForm_ui.py ../ui/configForm.ui

I also learned to use the .qrc file for resources like images. The .qrc file can be converted into python source code using  pyrcc4 tool

pyrcc4 -o images_rc.py images.qrc

The qrc file is also an xml file which contains the references to the images used. It can be created by just editing.

<RCC>
    <qresource prefix="/images">
        <file alias="sunny.svgz">../images/sunny.svgz</file>
        <file alias="showers.svgz">../images/showers.svgz</file>
        <file alias="not-available.svgz">../images/not-available.svgz</file>
        <file alias="cloudy.svgz">../images/cloudy.svgz</file>
        <file alias="thunderstorms.svgz">../images/thunderstorms.svgz</file>
        <file alias="haze.svgz">../images/haze.svgz</file>
        <file alias="windy.svgz">../images/windy.svgz</file>
    </qresource>
</RCC>

I decided to write this weather plasmoid in python, because all the other weather plasmoids I found were binaries. I have also tried to keep the data and presentation layer separate, I hope I succeeded in that.  In fact plasma framework provides a very good way of doing that in terms of data engines. I would also like to use the data engines, may be with this or other plasmoid I may develop.

The svg images for weather conditions are taken from kde-look. The credit goes to the original artist, painkiller10. I have considered only a number of weather conditions, so If you see a question mark image as the weather condition, let me know which condition it is, so I can update the code to consider it.

Please feel free to report any bugs or suggestions for improvement. I am sure there is a big room of improvement from code point of view as well as functionality. I am also open for changing the layout or changing the information displayed if someone comes with a better suggestion than the current one.

Some more screen shots:

Looks almost like conky with the seamless theme.

With settings dialog box

]]> http://research2009.wordpress.com/2009/08/13/python-getting-started/ Thu, 13 Aug 2009 06:55:59 +0000 Dan http://research2009.wordpress.com/2009/08/13/python-getting-started/ http://okursat.wordpress.com/2009/08/03/eclipse-ve-pydev-python-duzenleyici/ Mon, 03 Aug 2009 08:07:57 +0000 okursat http://okursat.wordpress.com/2009/08/03/eclipse-ve-pydev-python-duzenleyici/

Uzun zamandır Python ile ilgili yazamıyorum. BİTEFO kursu okul sonu işleri falan derken en sonun da biraz zaman buldum ve Eclipse kurarak Python kodlamayı buradan yapma isteği oldu. Zaten Eclipse ve PyDev paketleri depoda mevcut bize sadece küçük ayarlamalar yapmak kalıyor. Şimdi dilimin döndüğünce size bu ayarları anlatmaya çalışacağım. Eclipse bilindiği gibi Java geliştirme ortamı, sadece  Java değil C ve Python da geliştirilebiliyor.

Depodan gerekli paketleri kurduktan sonra Pardus-Uygulamalar-Geliştirme yolunu kullanarak Eclipse programını çalıştıralım. Eclipse programına Python yolunu(Path) göstermemiz gerekmektedir. Bu pencerede İnterpreter-Python bölümüne tıklayarak ilgili bölümün açılmasını sağlıyoruz. Bu pencerede New… düğmesine tıklıyoruz.

New… düğmesine tıkladıktan sonra karşımıza aşağıdaki gibi bir pencere çıkıyor. Bu pencere Interpreter Name kısmına ben Pardus 2009 kullandığım için Python 2.6 yazdım. Çünkü Pardus Python 2.6 kullanıyor. İnterpreter Executable bölümnüde hemen Browse… düğmesini tıklıyoruz. Pardus 2009′ da Python yolu /usr/bin/python2.6 dır. Bu dosyayı seçerek OK düğmesine tıklıyoruz.

Eclipse var olan kütüphaneleri kendisi otomatik olarak buluyor. Burada da OK düğmesine tıklayarak geçiyoruz.

Artık başladğımız yere geri dönüyoruz. Program bulduğu Python kütüphaneleri ve yolunu ilk girdimiz pencereye bilgi olarak girdi ve OK dememizi bekliyor. OK diyerek artık Eclipse programının Python kodlayıcı(editör) olarak çalışmasını sağlıyoruz.

Eclipse artık Python’ u ve kütüphanelerini tanımaya başlıyor.

Yeni proje oluştur diyerek Eclipse’ i Python kodlayıcı(editör) olarak kullanabilirsiniz. Hayırlı olsun. İyi geliştirme süreçleri dilerim.

Bu yazı da burada biter.

Don’t worry my friends: despite of the title of this post, I’ve been eating ok. The problem was not about food this time, it was about RSS Feeds and some libraries that deal with those, which I had to use for a project recently.

I needed a blog-planet-like solution for a website we are mounting with Joomla. Yet it wasn’t the simple type of read-them-all planet (like Planet Planet), because it needed admin approval and should integrate to Joomla. Because of the perpetual-polling mode needed, there was no Joomla module that could help us there (Joomla is not a server), and because of the level of specialization, I had to roll our own solution to it.

I was warned, through this book I once read (which I strongly recommend for anyone that has anything to do with web programming) that dealing with RSS Feeds was not exactly straightforward. The obvious thing was that I needed a library, so I started searching for what RSS Joomla modules were using. I found Simple Pie, which seemed to be a pretty straightforward standard solution (and had a beautiful website not that it would help me code better, but anyways). I coded a little sample and tried it out… and nothing happened. I moved around some stuff in the code, tried again and nothing. I was pretty sure I was following instructions correctly so I couldn’t imagine what was wrong… until I read the documentation with more detail and grepped the code for the $_SERVER variable and there it was. I then uploaded the code to my personal web server and tried it out from the web browser and it magically worked, so it was clear to me that Simple Pie requires to be inside a server to run. Given the fact that we’d probably want to run the polling in a separate server (not the web server), I had to discard that library and it’s beautiful website.

My next try was Mark Pilgrim’s Universal Feed Parser which had the great disadvantage of being in Python, a language I can code in but I avoid, specially because PyDev hasn’t been a great solution for me as an Eclipse plugin (don’t waste your time suggesting me another IDE… it’s Eclipse’s way or no way; instead support the Dynamic Languages Toolkit project for Eclipse ). Yet it’s the one Planet Planet uses, so it had to be good enough for my purposes.

And it kinda was, I tried out some code samples based on intuition and the small documentation and got a little program working. I learned some things while doing so, for example the fact that Blogspot has no summary information for posts like WordPress does (i.e., WordPress rulz) so I had to do a workaround for that (i.e., Blogspot sucks). I then started to build all the rest of the stuff: DB integration with MySQL module, MIME emails with email module and smtplib module (hard to find helpful documentation on this) and everything was working quite fine (despite the spaghetti code I came up with) until I checked that the sample e-mails the script was sending had my author name instead of the title of my post. I was running tests with my blog and di3go’s one and all of di3go’s posts were looking ok. I was really puzzled, and I started checking everything from my code to the XML output of both pages… nothing seemed wrong. I finally had the idea of checking the Universal Feed Parser’s buglist, and there it was, a bug that only happened with WordPress (I’m a lucky guy, huh?) so I downloaded a nightly build from the code and everything was working fine then.

I tgz’d the code up and sent it away thanking God it was all over. All of this took me like 4 hours though, so I’m pretty sure I paid my RSS Feeds nightmare hours of the year and don’t want to be dealing with those anymore at least in the short term. Now some final disclaimers: Simple Pie looks like a very cool solution; Universal Feed Parser is a great tool, and simplifies the job a lot (that’s as simple as you’ll get because of the difference between the RSS, Atom and mixed standards out there, and each site’s implementation of those); so my props to these two projects.

I earlier tried various editors I was considering using to teach IronPython.  One of the glaring omissions was Eclipse/PyDev, which has built-in support and is a very well-known IDE (particularly in the Java community).  The main reason that I skipped Eclipse was that when I was searching for an IDE to use professionally about five years ago I tried Eclipse (for Python, C, and C++ development) and I really hated it – the IDE was very slow (especially to launch), it was very Java-centric, and just didn’t suit me at all.  I’d briefly tried Eclipse before that as well, with similar results.

Over the last few days, I decided that I was probably being unfair, and since this was a choice for my students rather than for me personally, I really ought to try Eclipse (with the PyDev extensions).  I also noticed recently a post about using IronPython with NetBeans – I’d heard of NetBeans before, but only in a Java development context, and since I stay as far away from Java development as I can, I had no experience with NetBeans at all.

Eclipse/PyDev

I was right to re-examine Eclipse.  The things that I remember bothering me so much five years ago (speed, the interface) seem to have been completely addressed, and it looks like a quite usable product.  When adding PyDev (which was quite simple), there’s support for IronPython that appears completely built-in (although it’s still obvious that Java is the #1 choice).  It seemed like a quite reasonable contender, unlike I tried to actually configure it to use the IronPython interpreter (which has to be done manually).  I was using a completely standard, fresh, installation of IronPython 2.0.1 (from the .msi) installed in the default location (here ‘C:\Programs\Iron Python 2.0.1′) with ‘Eclipse Classic 3.5′ and version 6u14 of the Java Runtime.

I believe that, in theory, you can click the automatic configuration button, or manually locate the IronPython interpreter, and it’ll just work.  Unfortunately, for me nothing seemed to work.  The error message indicated that having spaces on the Eclipse path could be a problem (which seems pretty shocking in 2009), so I tried moving Eclipse to C:\, which didn’t help.  I tried moving IronPython to C:\ (and renaming the folder to have no spaces), and that didn’t help.  I imagine that someone more familiar with Eclipse, or with PyDev with CPython/Jython, might have been able to solve this easily.  However, if I can’t figure it out in 10 minutes, then I am not at all comfortable with telling my first-year students to use it (even though we walk through the installation together, some of them will need to do that by themselves as well).

NetBeans

It wasn’t entirely clear which version of NetBeans to use, but I presumed that the most appropriate was NetBeans 6.7 “Python EA2″.  Although the post I saw indicated that you needed to rename ipy.exe and ipyw.exe, I found that just selecting ipy.exe worked fine.  I quite liked this IDE, and it appeared (although I didn’t use it for long) that using IronPython worked fine.   There’s no graphical form designer, so NetBeans is in the same category as Komodo Edit (which I discussed previously).  In many ways, it’s probably a better choice than Komodo Edit (in that the IronPython integration is simpler to do, although it does require that Java is installed), although I don’t know if there is any way to provide .NET auto-complete.  It’s a fairly full-featured IDE, like Komodo and unlike DIE, which would normally be a positive, but in this specific case (first-year programming students) is actually a negative, since they need to ignore all the ‘team’ functionality, and you have to work within projects (which is true of Visual Studio as well).  This is an “early access” version – since I’m not familiar with NetBeans I don’t know how unreliable that makes it – it makes me a little nervous about suggesting it to students, but I certainly didn’t have any trouble with it myself.

Conclusion

If you’re able to get Eclipse/PyDev installed, then I suspect it might slightly beat out my previous recommendations of Komodo Edit and DIE; since I didn’t get it working, I can’t recommend it to the students.  NetBeans, however, will get added to the list of suggested tools (alongside Komodo Edit and DIE).  If I wasn’t so familiar with Komodo Edit, I’d probably use NetBeans as the editor I use to demonstrate, but it didn’t wow me so much that it overcomes the familiarity.

In my old blog I talked about how I tried to find themes similar to that of TextMate to use on Eclipse. And if you’ve bothered to read up more on TextMate themes, you’d surely understand the reason why. Basically, I found the default theme on pydev, or in general, the whole editor, too bright for long usage and wanted to find a way for me to use dark and elegant themes for the pydev editor.

Unfortunately, I wasn’t able to find any plugins that supported the use of TextMate themes and had to settle for a manual configuration using the color customisation feature in pydev itself. Results turned out to be good and I was happy with what I’ve managed.

p.s. After churning out a similar post back in my old blog, I’ve had people leaving messages, asking me to export my settings for distribution. Unfortunately, pydev configurations do not get exported correctly and it would be pointless for me to distribute a non-working file. So unless someone can help me with this, I’m just going to use the settings for myself.

Bueno, luego de una soberana lata, por fin nos vamos a entrar en la programación. Finalmente entre los muchos lenguajes de programación existentes me pareció que el mejor para comenzar es Python.

¿Por qué Python?

• Lenguaje de alto nivel interpretado
• Sintaxis sencilla (prácticamente pseudocódigo)
• Ampliamente disponible
• Libre
• Multiplataforma
• Orientado a objetos

En fin, como ven las bondades son numerosas…

Para programar con este lenguaje basta un editor de texto plano (nada de MS Word, u OpenOffice) o el intérprete, en el primer caso es suficiente, pero de todas formas un IDE puede facilitar bastante las cosas. El que siempre es recomendado es PyDev, un plugin para Eclipse, pero la verdad es que como les comentaba en los artículos anteriores no me gusta mucho utilizar aplicaciones basadas en Java. De todas formas en Ubuntu el paquete se llama eclipse-pydev.

Hay otro llamado Komodo, que es de pago (bastante profesional por cierto) y Komodo Edit que es la version gratuita y libre. Otro de pago al parecer muy bueno sería Wing IDE que según leía en Python para Todos, con suerte podrían darte una licencia profesional si lo utilizas para desarrollar software libre no comercial.

Yo voy a utilizar Geany (geany), porque cumple perfectamente mis expectativas, tiene coloreado de sintaxis, autocompletado, edición en pestañas y abajo tiene una pequeña terminal donde se pueden ejecutar los programas que creamos. Por otra parte es muy liviano, rápido y ha demostrado ser bastante estable.

Respecto al intérprete, puedes instalar iPython (ipython) que viene siendo una versión mejorada del intérprete común y silvestre. Al menos en el comienzo creo que es más lo que enreda por ser más avanzado, así que no lo utilizaré.

Si te sientes incómodo utilizando la línea de comandos, también podría recomendarte IDLE un IDE de Python que es un intérprete, a medio camino entre el “a secas” y lo estrambótico de iPython.

Para este tutorial, utilizaré IDLE, pero con cualquiera deberías andar bien.

¡Hola mundo!

Como es costumbre en esto de la programación, para comenzar vamos a realizar nuestro primer programa que imprimirá “Hola Mundo!” por la pantalla. Para entonces vamos a arrancar el intérprete (o IDLE, lo mismo)…

pablo@xubuntu:~$ python
Python 2.6.2 (release26-maint, Apr 19 2009, 01:56:41)
[GCC 4.3.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>

La última línea (>>>) es el prompt, es decir que python está esperando que tipiemos alguna orden.

>>> hola
Traceback (most recent call last):
    File "", line 1, in
NameError: name 'hola' is not defined
>>>

Como ves, Python no reconoció el comando “hola”, vamos a probar con otro…

>>> print "¡Hola mundo!"
¡Hola mundo!
>>>

¡Felicitaciones! Tu primer programa en Python .

Para salir del intérprete puedes hacerlo de tres formas: exit(), quit() o con <Ctrl + D> (comando de fin de línea; EOF)

La otra forma que puedes programar es escribir lo anterior en un archivo de texto y guardándolo con extensión .py:

#!/usr/bin/env python
# coding: latin-1

print "¡Hola mundo!"

La primera línea es un comando Unix que se conoce como shebang, hashbang o sharpbang. Su función es indicar en que ruta buscar el intérprete, si estuviera programando en bash, tendría que cambiar “python” por “bash” o el que corresponda. Habitualmente el intérprete de Python se encuentra en /usr/bin/python, pero como por desgracia eso no está estandarizado, preferiría asegurarme de que lo encontrase si acaso estuviera en una ubicación poco habitual. Para eso utilice el comando env que se encarga de ubicar al intérprete, así corro menos riesgos que no lo encuentre.

La línea siguiente es para que Python entienda más caracteres: mira que pasa si ejecutas sin la segunda línea, tirará un error porque el carácter ¡ no es ASCII. En fin, si quieres utilizar caracteres presentes en el castellano y no sólo los provenientes del inglés (básicamente ASCII) agrégalo, sino puedes omitirlo.

Por supuesto, además de añadir esta línea debemos darle permiso de ejecución:

~$ chmod +x hola.py

Luego ya podemos ejecutarlo con:

~$ ./hola.py

En ambos casos obtendremos los mismos resultados, con el intérprete tenemos la ventaja que no necesitamos darle permiso de ejecución ni estar guardando el archivo, por lo que utilizaré este.

Si están familiarizados con algún otro lenguaje, notarán que no es necesario agregar el punto y coma al final de cada línea ;, puedes agregarlo si quieres, pero no tendrá ningún efecto. Si agregas código después, Python lo considerará como un salto de línea, pero la verdad es que no es muy buena idea porque sacrificas algo de legibilidad.

Ingredientes e instrucciones

¿Recuerdas la receta que puse en un par de partes atrás?

1. Mezclar azúcar y mantequilla hasta que quede una sustancia cremosa
2. Agregar 3 huevos
3. Mezclar y agregar 2 tazas de harina
4. Cocinar en un horno a llama baja por 45 minutos

Bueno, nuestra receta tiene ingredientes ¿verdad?, huevos y harina (por ejemplo) y también presenta instrucciones (statements), como mezclar y cocinar. Un programa tiene ambas cosas, éstos serán los temas les hablaré en las siguientes partes (comenzando con los ingredientes).

Nota: Lamento lo corta, poco interesante y como si fuera poco – la tardanza para escribir esta parte, pero me costó mucho decidirme y la verdad es que tuve que rehacer varias veces porque no sabía cuál de las siguientes dos partes poner primero. Lo bueno es que quedé con todos los artículos a medio hacer, así que voy a poder desarrollarlos más rápido.

Well I decided to take some time off from working with the App-engine-patch and try Native Django,, go more mainstream so I could take advantage of more robust database and tutorials…

I’m using Python 2.62 Win 64 Eclipse 3.4 Ganymede, and trunk SVN Django 1.1

1st, one must install a Mysql driver The one in the “official library won’t work, version differences.. go here for a windows installer for Python 2.6 https://sourceforge.net/forum/forum.php?thread_id=2316047&forum_id=70460  Fwiw I’m using 32 bit versions although there is a 64 bit version available (for both Python and the Mysql driver (lower down on that thread).

You also need to add the following change manually to the Mysqldb code

About warnings:

1) file “__init__”, replace:

from sets import ImmutableSet
class DBAPISet(ImmutableSet):

with

class DBAPISet(frozenset)

2) file “converters.py”, remove:

from sets import BaseSet, Set

3) file “converters.py”, change “Set” by “set” (IMPORTANT: only two places):

line 48: return set([ i for i in s.split(',') if i ])
line 128: set: Set2Str,

I hope this be useful.

Regards,

Luis Moreno

I realized That I had not been documenting myself when I blew up and was about ready to re install and realized I’d have to look every thing up again… Hence back to posting!

One of the most interesting revelations for me recently is how Python “installs” and referrers to packages and extensions. At this point I now think that all the trashing about is a bit too much on many installs. Looking in site-pkges in Libs in the Python directory I noticed several .pth files named for some of the extensions I was installing and using, the file was the module name.pth.. and contained the full path to the module… cool! So that is a mechanism that can be used to create a nice place to keep that stuff without messing up your basic Python install… good to know..

Another major revelation has been the use of revision control systems,,, It seems that it is well worthwhile to have a copy of all of the major systems on your machine. Git, SVN and Mercurial. If you checkout a copy of a system like Django,,, then when you want a update to the current version just do another checkout and your done!

Btw it turns out that even if you use TortoiseSVN as I do it is a good ides to install Silk SVN also because Tortoise does not provide command line access, which is used by some packages for automated installation/updating, in particular Pinax! So even if you don’t want command line you need to have it on your system…

If you use tagging with the 1.0 or latter Django you must use the svn version of tagging ….

Empezando a programar en Phyton, estuve buscando un buen entorno gráfico para programar y decidí instalar Eclipse que es un entorno de desarrollo integrado de código abierto multiplataforma para desarrollar “Aplicaciones de Cliente Enriquecido”.

Eclipse es un Ide de java, pero se pueden poner plugins para poder programar en Phyton, c++.

Para programar en phyton, hay que instalar Pydev que es un plugin que se instala en Eclipse, la instalación la puedes hacer desde Synaptic es muy fácil, solo buscas Eclipse y Pydev.

Ya que instalas Eclipse y Pydev hay que configurarlo:

En el menú de la ventana principal, elegir Ventana -> Abrir perspectiva -> otro.

Se abre una ventana para elegir la perspectiva, vamos a elegir Pydev, y se abre una ventana que es entorno para desarrollar con phyton.

Ahora para configurar Pydev, hay que ir a menú -> Ventana -> Preferencias

Nos vamos a Pydev en el arbol de opciones y seleccionamos  “Interpreter – Python” y seleccionamos new y nos vamos a la ruta usr/bin y buscamos el archivo llamado “phyton”, damos aceptar y asi debe de verse:

Y listo ya puedes depurar tus programas desde Eclipse.

Esto es solo una opción para programar en Phyton, existen varios entornos para programar mas ligeros, o si no quieres instalar nada, desde consola es posible también.

Bueno aqui les dejo algunos buenos tutoriales  que me han servido para programar en Phyton:

-Phyton para todos

-Phyton Tutorials

-Introducción a la programación con Python

]]> http://10thvirtue.wordpress.com/?p=15 Fri, 29 May 2009 22:12:34 +0000 luke http://10thvirtue.wordpress.com/?p=15

In order to begin work on my project, I want to make sure I’ve got a tidy work bench to start the Python part of my project (again, I’m developing in Windows XP).

Advice from others as well as personal preference yields the following:

Interpreter: Python 2.6.2
Reason: It’s the current production version

IDE: Eclipse Ganymede
Reason: I had Ganymede already on my system from a recent Salesforce.com dev project and to facilitate an android tether.  As much as I loved being forced to learn to write C++ from vi in college, I was ruined by the fancy-pants Microsoft Visual Studio years ago when I did a lot of coding in Visual Basic.  It’s just easier to keep track of things, and autocomplete is a life-saver for those of us who haven’t memorized all of the names of all of the library functions in whatever language we’re using.  I love Notepad++ for its immense buffer, its myriad handy text functions, and its language highlighting, and I often end up writing code in there just because it doesn’t take 5 minutes to start the program, but I try to suck it up and go to my IDE before too long.

Version Control: Mercurial 1.2.1
Reason: Stuart Ellis says so.  In all seriousness, I am a stickler for version control (not to mention internal documentation) when I write code, generally speaking.  After completing a working first draft, I save it as an 0.1 version, then start redrafting by commenting out the complete old code and writing the revised code below for each step.  When I’ve got the second draft working, I describe what I did in the header as a changelog, save a copy of it as 0.19, then remove commented old code and save clean version as 0.2.  This is great, because it allows me to reference earlier versions and track code’s path of evolution, but is also a pain in the neck.  Embedded version control makes this easier.  Anybody who’s been embarassed by sending or receiving a Word document containing all prior revisions complete with misspellings, poor grammar, and filthy language will know what I’m talking about.  It’s a handy thing to have once you’ve figured out how and when to use it.

OK, that’s great, you say.  Doesn’t Eclipse, your IDE, have a CVS-compatible version-tracking system built-in?  Well sure, but I don’t have a CVS server to govern my commits.  Mercurial is decentralized.  I love decentralized systems.  I love to study them and figure out whether it’s wise to incorporate them into my daily life.  Plus, if the Python, Google, and Mozilla people are using it, it has to be pretty decent.  How often have you made an arbitrary, irrationally-based decision in your life?

Other Important Tools:

• Setuptools – This is a package manager for Python — a couple people advised me to do nothing without it.  After attempting a few library compiles from the source .tgz, I’m happy to let a utility handle the installation and maintenance of libraries.
• Virtualenv – Virtual Development Environment — It allows me to create “clean” workspaces that are separate and distinct in their libraries, versions, etc.  In the words of one of my python advisors, “You’ll save yourself a lot of pain if you only work in and install Python modules to an insulated virtual environment, without polluting your system-wide Python installation.”  It’s a bit of a pain to set up with the IDE, but the instructions below should make it clear.

Order of operations:

Python:

I downloaded the newest .MSI from python.org and installed it to the folder ‘C:\Python26′.  Clean and simple.

I manually created the folder ‘C:\Python26\Scripts’ because setuptools wanted me to.

I modified my system’s PATH: right-clicked on My Computer, selected Properties, clicked Advanced, then Environment Variables, and added “;C:\Python26;C:\Python26\Scripts” to the end of my PATH statement (by highlighting it in the top box and clicking “edit”).

Setuptools:

I went to the setuptools download page and saw there was no .exe installer for python 2.6.

I downloaded the win32 py2.6 .egg and couldn’t figure out what to do with it.

I attempted to install from the source and that didn’t work either.

I googled “setuptools python 2.6″ and found this gem of a website, which gave me the following set of instructions with which I found success:

1. Download setuptools-0.6c9.tar.gz
2. Download setuptools-0.6c9-py2.6.egg to a folder(directory) outside your Windows Python installation folder
3. Use 7-zip to extract ez_setup.py in the same folder as setuptools-0.6c9-py2.6.egg
4. Go to the corresponding dos prompt and run python ez_setup.py setuptools-0.6c9-py2.6.egg from the command prompt
5. Ensure that your PATH includes the appropriate C:\Python2X\Scripts directory.

Et voila.  Thanks, bhadra!

Virtualenv:

With Setuptools installed, I simply typed the following at the C:\ prompt:

\> easy_install -U virtualenv

Which errored out, saying it couldn’t find a module named win32api.

30 seconds on google later, I found pywin32.

Then, I went back to the C:\ prompt and typed:

\> easy_install -U pywin32

Which returned successfully.  I then retried

\> easy_install -U virtualenv

And that worked out just fine.

Mercurial:

I went to the Mercurial download page, which told me I could obtain the newest version on my “modern system with Python and SetupTools installed” by simply going to my command line and typing:

\> easy_install -U mercurial

Well, that returned this:

error: Setup script exited with error: Unable to find vcvarsall.bat

So now I need to figure out what vcvarsall.bat is and why I don’t have it.

Google tells me this is my Visual Studio C++ Compiler.  I don’t have Virtual C++ installed on my machine.  I download Visual C++ Express.  What the hell, I install optional Silverlight and MS SQL Server Express 2008 as well, just for kicks.

This looks like it might take a while.  I go fold some laundry and shift clothes from washer to dryer.  OK, still not done.  I’ll take the dog out for a walk.  OK done, now gotta reboot.

With Visual C++ Express installed, easy_install -U mercurial at the prompt now returns:

Finished processing dependencies for mercurial

Looks like we’re in business with version control.  After finishing this process, I stumbled upon this page, which seems to indicate I did what I was supposed to do, but explains it better and gives more options.

I’m told to modify mercurial.ini to change a few things around.  First, I need to find it.  A system search tells me it doesn’t exist.  I wonder if because I used easy_install, it created a Un*x-style .hgrc init file for me instead.  Another system search reveals no .hgrc, either.

OK, maybe I’ll just go ahead and make a new one.  I’m creating a new file called “mercurial.ini” in my C:\Documents and Settings\[username]\ directory (where username is the name I use to log in to my machine).  I’m adding the following lines:

[ui]
username = Luke <luke@xyz.xyz>
editor = C:\Progra~1\Notepa~1\notepa~1.exe
[extensions]
hgext.graphlog =

And then I’m saving and quitting.  The lines under [ui] tell Mercurial who I am, and what my preferred editor is.  The lines under [extensions] tell Mercurial I want to be able to use glog, which is a handy ascii-graph representation of a development chain.

Eclipse:

I already had Eclipse (3.4.1) installed on my machine, which I installed by downloading and installing Java SE JDK, downloading and unzipping Eclipse Classic to ‘C:\Eclipse’, and creating a shortcut on my desktop to ‘C:\eclipse\eclipse.exe’

Eclipse-Pydev:

In Eclipse 3.4.1, it’s pretty easy to perform modular installs of different “plug-ins” that turn Eclipse-the-vanilla-memory-hog into Eclipse-the-smart-[language]-development-environment.

A little off-putting but strangely appropriate, Eclipse (3.4.1) hides its Software Updates utility in the Help menu.  Click “Help”, then “Software Updates…” to bring up the dialog titled, “Software Updates and Add-ons”

To be honest, I learned how to install PyDev in Eclipse by watching this video on showmedo, which is the visual version of this manual from fabioz.

Mercurial Eclipse:

Wicked simple to install.  Check out the homepage.  Head to Eclipse’s handy Software Updates page, click to the “Available Software” tab.

As it turns out, following the instructions on the website yielded a broken install (because the latest production version of MercurialEclipse isn’t compatible with the versions of everything else I’m using).  So instead, do this:

Click the “Add Site…” button.  Enter http://home.zingo.org/eclipse-betaupdate/ and click “OK.”

Expand the new item appearing in your Available Software list named “file:/home/zingo/projects/src/www/eclipse/mercurialeclipse/ – metadata”, check the box next to “com.vectrace.MercurialEclipse”, and click the “Install…” button at the top-right.  Click “OK” a few times, it’ll ask you to reset Eclipse, BOOM.

At least that’s what I had to do to make it work after I found a dead end on the MercurialEclipse homepage and was sent here.

Configuration:

Now to get it all working together.

First, I’ll create a virtual environment in the C:\Dev folder named “GContactsCleaner” with

\> virtualenv GContactsCleaner

Now I’m going to run Eclipse, click “File…Switch Workspace…Other…” enter “C:\Dev\GContactsCleaner\” as the new workspace, and watch as Eclipse reboots itself.

Now I have to click “Workbench” from the Eclipse launch screen to get to the workbench.  By default, Eclipse puts me in a Java IDE.  I have to click the icon to the left of the Java icon in the top-right and click “Other…”

Next, I select “Pydev”

It tells me I need to fix my Mercurial install.  Indeed.  I’ll locate my mercurial executable (C:\Python26\Scripts\hg.bat) and set up my mercurial username.  I click “Apply”.  I also need to click “Pydev … Interpreter – Python” and set up my virtualenv’s interpreter, which is now located at “C:\Dev\GContactsCleaner\Scripts\python.exe” and I name it “GContactsCleaner – python 2.6.2″.  I tell it OK, and OK again.

Now all I have left is to create my project and set it up with MercurialEclipse.

First step, “File…New…Pydev Project.”  I name it GContactsCleaner (which places it in the awkward C:\Dev\GContactsCleaner\GContactsCleaner folder).

I right-click the newly-created “GContactsCleaner” and click “Team…Share Project…” to bring up the “Share Project” dialog.  I tell it I’d like to use MercurialEclipse as the repository plug-in, accept the default directory (the project root) and click “Finish.”

If all went well, that should do it.  So far the only awkward thing I’ve had to do now that it’s all set is to add anything installed by virtualenv-activate easy_install again in Eclipse as a library to my interpreter.

Whew.  Now I’ve just got to remember to activate.bat my environment before I use easy_install to bring in a required library so I can avoid corrupting my global python setup.  I feel this is inevitable, and at some point I’m going to have to post the steps for manually uninstalling something that was easy_installed.

Recently I have started developing an application using the excellent Python web framework web2py. Web2py comes with its own a web-based integrated development environment that makes it easy to write small web based applications from within your browser. However once you start developing something bigger you will want the convenience of a real IDE. Code completion, multiple open files and a debugger will all make the experience more comfortable. However due to web2py’s mode of operation your IDE will require some additional help from you to allow its full powers to blossom.

Web2py’s mode of operation

Contrary to other Python web frameworks, such a Django, web2py doesn’t use Python’s import statement to load your code. Instead it executes your code using Python’s built in function execfile and supplies it with a prepared environment that contains a number of global objects that are central to web2py’s programming model (e.g. request, response, session objects, HTML helper functions, etc). This also means that your IDE has no knowledge of these objects and functions unless you explicitly tell it about them.

Informing your IDE about web2py’s prepared environment

Even though I use Eclipse/PyDev, the trick to let any Python aware IDE know about these objects is the same. In fact I got the idea from the How-To Using Wing IDE with web2py.

From the IDE’s point of view there are two types of files that it requires additional information about:

• models
• controllers

Simply adding import statements for the global objects and functions web2py is going to provide us with at runtime might cause unforeseen problems. Hence we need to import them conditionally.

For models adding the following snippet of code at the top will suffice:

if 0:
    from gluon.sql import *
    from gluon.validators import *


For controllers the following will do:

if 0:
    from gluon.globals import *
    from gluon.html import *
    from gluon.http import *
    from gluon.sqlhtml import SQLFORM, SQLTABLE, form_factory
    session = Session()
    request = Request()
    response = Response()


How does this work? The conditional 0 will always evaluate to False. This means that at run-time the statements following the if statement will never be executed. It’s dead code and hence will never interfere with whatever web2py has setup for us in its prepared environment.

It’s different for the IDE. The Python parser that’s part of your preferred Python IDE only parses your code. It does not evaluate it as Python does. As such it has to take the possibility into account that it might be executed at some point in time and that other code might depend on it. It has to read in the imports and consequently has all the information needed for code completion. Your IDE is now aware of web2py’s prepared environment

Well, we have decided which tools we are going to use for our semester project. The winners are:

Eclipse with the following plugins:

• PyDev (For python Development)
• Subclipse (For SVN connectivity)

And for our development framework (after a period of uncertainty):

Django was the clear winner.

PostgreSQL will be our DBMS.

Eventually we’ll configure the Apache HTTP Server to work with mod_wsgi for Apache-Python interpretation.

Shortly I’ll post on how to get all those working nice together.

Until then.

Despues de haber trabajado con Netbeans por varios meses, he venido probando tambien este plugin de Eclipse PyDev, y en verdad me parece muy bueno, creo que sobre todo en velocidad aunque esto es relacionado a la plataforma porque netbeans como todos sabemos consume mas recursos que Eclipse.

Features a resaltar;

• Autocompletacion
• Construccion de metodos y clases
• Debugger
• personalizacion de source paths en proyectos para agregar librerias externas
• Velocidad en carga de outlines y propiedades (esto es Eclipse)

La simplicidad que brinda para poder desarrollar con cualquier libreria sea Django, appengine, openobject y en fin cualquiera que este en tu PYTHONPATH o la agregues a las propiedades de tu proyecto pues va de pelicula, altamente recomendado para un Python developer.

I picked up Python around 2 months ago and was amazed by the robustness and extensibility of the language. Eclipse is my IDE of choice and I do most of my python coding in pydev. However, the default eclipse themed colors was extremely glaring and it really took a toll on me and hindered my output.

Yesterday, I came across TextMate. I’ve never used it before but have heard rave reviews on it. I decided to read up more about it and lo and behold, I discovered TextMate themes.

“I could code to these themes all day”, I thought to myself.

I assumed some smart guy must have written a plugin for eclipse that allows some form of theming on Eclipse. I was wrong.

The only thing closest to it was Afae editor which wasn’t exactly what I wanted since

1. you had to use the editor itself instead of pydev to code

2. bad syntax highlighting support for python

I then remembered pydev itself allows customisation of color options. I fired up Eclipse and indeed  it was there – but lacking. Still I decided to use whatever was available and this is what I’ve managed so far.

Bye bye bloodshot eyes.

Well I had a long and frustrating week/week-end, all sort of run together. I discovered that my new site would not take even moderately long articles. This is apparently a “known problem” and it relates to exploding indexes, as somewhat explained here.

I finally got to corresponding with one of the Bloog Maintainers who had it turned out created a modified site search capability using Google Site Search. According to him  it still does not provide for longer article without some code mods that I have not yet started. But is a prerequisite. I got a copy from Git-hub, where Bloog is hosted. This required that I get and install GIT version control system. I chose to start with Windows based  Git Extensions. It still required that you install the basic GIT. It is only available in Tar format you will need 7zip to unpack although after a posting the developer has now provided a “full” option for Git extensions.

I then tried to apply the new code to my existing Bloog version as I had modified it. That required a differential editor,which I did not have Kdiff3 turned out to be a great choice. It compares entire directory structures and than lets you click through the files and selectively choose to apply a, b to your revised file. Very cool.

I then tried to fire things up, FAIL. I then went back to the Version I had just obtained and I could not get it to fire up either. I then started to look for “real” debug information. Not much available.

Eventually I downloaded PYdev for Eclipse, and that was a major improvement  my entire development environment. In fact I would go so far to say Do not attempt development for APP-Engine without Pydev!! It provides a much better editor, code outlining and a runtime environment. There are several tutorials on setting up Eclipse for app-engine. Use them!!! Supposedly it also provides breakpoints, but I have not been able to get that working yet, but the other improvements are a major joy. The Debug environment did give me better log messages. Through which I was eventually able to make some headway. I found out that the two versions had changed the DB schema slightly so I had to delete a few older records You can see and modify the local datastore using http://localhost:8080/_ah/admin/datastore and bang it all started to work. It actually took a long time to go through each step, and I still have to go back and learn each of the new tools much better.

I’ve had a short free time to continue my studies with python.

I decided to look for Eclipse using python mainly because of my frustration with Visual Studio 6.

I enjoy developing in eclipse and miss the feeling of the quickness of accessing what you want during my Struts development times. I wish that same ease of development were available with my current project.

I am doing this to reminisce those times and to keep that mastery and enjoyment of eclipse.

To setup my environment, I used this link.

That’s all!

Bueno para los que como yo vienen de otros lenguajes de programacion y estan interesados en comenzar con Python creo que conseguir informacion no es lo dificil sino saber elegir.

IDE

En el campo de IDEs y editores de código gratuitos PyDEV (http://pydev.sourceforge.net/) se alza como cabeza de serie. PyDEV es un plu-gin para Eclipse que permite utilizar este IDE multiplataforma para programar en Python. Cuenta con autocompletado de código (con información sobre cada elemento), resaltado de sintaxis, un depurador gráfico, resaltado de errores, explorador de clases, formateo del código,
refactorización, etc. Sin duda es la opción más completa, sobre todo si instalamos las extensiones comerciales, aunque necesita de una canti-dad importante de memoria y no es del todo estable.
Otras opciones gratuitas a considerar son SPE o Stani’s Python Editor (http://sourceforge.net/projects/spe/), Eric (http://die-offenbachs.de/eric/), BOA Constructor (http://boa-constructor.sourceforge.net/) o incluso
emacs o vim.

Si no te importa desembolsar algo de dinero, Komodo (http://www.activestate.com/komodo_ide/) y Wing IDE (http://www.wingware.com/) son también muy buenas opciones, con montones de características interesantes, como PyDEV, pero mucho más estables y robustos. Además, si desarrollas software libre no comercial puedes contactar con Wing Ware y obtener, con un poco de suerte, una licencia gratuita para Wing IDE Professional.

Fuente “Python para todos” de Raul Gonzalez Duque.
http://mundogeek.net/tutorial-python/

Por mi lado, tomando la sugerencia de nuestro amigo Raul,  y dado que estoy familiarizado con Eclipse, creo que la mejor eleccion es PyDEV.

Instalacion de PyDEV

Linux – Ubuntu, en el caso de que tengan Ubuntu 8.04 esto es muy facil. Utilizando Synaptic Packet Manager, pueden descargar el paquete pyDev y automaticamente se instalara el IDE Eclipse y el SDK de Eclipse con todas las dependencias y plugins necesarios para pyDev. O desde consola:

sudo aptitude install eclipse-pydev

En cuanto al interprete, en el caso de Ubuntu 8.04 creo que viene por defecto. De no ser asi lo bajan de la misma manera:

sudo aptitude install python2.5

Para otras formas de instalacion pueden ir a http://begnu.wordpress.com/2007/09/26/pydev-python-eclipse/

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