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Posts Tagged "python"

OpenMetaverse (formerly known as libsecondlife) Bot in IronPython

Posted by on Feb 8, 2009 in IronPython, Python, SecondLife | 0 comments

The OpenMetaverse documentation seems very dire in any up to date examples, especially in mono and non-existent for IronPython.

After few minutes of playing around with it let me share with you an example how to start off with making your own bot in SecondLife using OpenMetaverse lib and IronPython:

First download and install Mono and OpenMetaverse( just follow the official instructions here )

When you finish this step you should be able to go to the bin/ directory within the folder where you’ve unpacked OpenMetaverse and see many .exe files. If you’re a Windows user just try to play around with them, if you’re on MacOSX or Linux try running them from the console by typing: mono program_name.exe

That’s the basic requirement. If you’re able to get pass that point you’ll need to install IronPython.

Try running command ipy from your console, you should see:

$ ipy IronPython 1.1 (1.1) on .NET2.0.50727.42 Copyright (c) Microsoft Corporation. All rights reserved.
>>>

Now the fun bit. Writing the actual bot.

Let’s follow the official example which logs into the SL grid, says hello and exits.

import clr
from System import *
from System.Text import *
from System.Collections.Generic import *

clr.AddReferenceToFile("OpenMetaverse.dll")
from OpenMetaverse import *

first_name = "John"
last_name = "Doe"
password = "pwd1234"

client = GridClient()

def Network_OnConnected(sender):
   print "I'm connected to the simulator...\n" # or Console.WriteLine("I'm connected to the simulator...")
   client.Self.Chat("Hello Grid!", 0, ChatType.Normal)
   Console.WriteLine("Now I am going to logout of SL.. Goodbye!") # or print "Now I am going to logout of SL.. Goodbye!\n"
   client.Network.Logout()

client.Network.OnConnected += NetworkManager.ConnectedCallback(Network_OnConnected)

if( client.Network.Login(first_name, last_name, password, "My First Bot", "Your Name")):
   print "Logged in\n"
else:
   print "I couldn't log in, here's why: %s" % client.Network.LoginMessage


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Django model fields in many languages

Posted by on Jan 8, 2009 in django, Python | 0 comments

So I found myself in a situation where I needed to have multilingual support for the DB in Django. i18n does a great job for static messages, but what about all that dynamic data, ie. news in multiple languages. Sure you could create a column per language you want to support but that’s an awful waste on the table, plus when you want to start supporting additional languages you have to alter the table to add columns — not a best, and definetly not the most user friendly way.

Another way around the problem is to create separate table for each table that requires multilingual fields. Every translation table would have a ForeignKey to the parent table and consist of all the fields that need to be in a specific language plus either a field or ForeignKey to a table that has the language code (for queries/identification which language is used).

I’ve created

django-multilingual-model to do just that and make it easier to use/query such tables.

Here’s an example: 


class Language(models.Model):
    code = models.CharField(max_length=5)
    name = models.CharField(max_length=16)

class BookTranslation(models.Model):
    language = models.ForeignKey("Language")
    title = models.CharField(max_length=32)
    description = models.TextField()
    model = models.ForeignKey("Book")

class Book(MultilingualModel):
    ISBN = models.IntegerField()

    class Meta:
        translation = BookTranslation
        multilingual = ['title', 'description']

lang_en = Language(code="en", name="English")
lang_en.save()
lang_pl = Language(code="pl", name="Polish")
book = Book(ISBN="1234567890")
book.save()
book_en = BookTranslation()
book_en.title = "Django for Dummies"
book_en.description = "Django described in simple words."
book_en.model = book
book_en.save()
book_pl = BookTranslation()
book_pl.title = "Django dla Idiotow"
book_pl.description = "Django opisane w prostych slowach"
book_pl.model = book
book_pl.save() # now here comes the magic

book.title_en
u'Django for Dummies'

book.description_pl
u'Django opisane w prostych slowach'
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Non-blocking use of Django models API

Posted by on Aug 1, 2008 in django, Python | 0 comments

If you’ve ever used Twisted framework and got through the first a bit hard learning curve, you most likely fell in love with it.
And if you’ve every used Django you most likely thought — isn’t there a way for it to run faster and in non-blocking fashion — especially if you want to write a web application that integrates other protocols.
One major block on the road is the DB models API which I’ll focus on now.

So let’s say you’re considering to use Django’s models in Twisted application.
Of course this does not automagically makes your code non-blocking. Just allows your blocking DB code to run without affecting Twisted’s reactor (too much). Be careful not to defer to thread too often! 

from twisted.internet import reactor, threads
from django.core.management import setup_environ
import settings
import string 

setup_environ(settings)

from foo import models

def getUser(user):
    print "Hello %s %s" % (user.first_name, user.last_name)

def handleError(e):
    print "Error %s" % str(e)

deferred = threads.deferToThread(models.User.objects.get, username='yazzgoth')
deferred.addCallback(getUser)
deferred.addErrback(handleError)
reactor.run()
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Amazon EC2 instance with pre-setup Django, Apache2 and MySQL

Posted by on Jul 12, 2008 in ec2, linux | 0 comments

Phoebe Bright asked me last week if I could create an Amazon EC2 for quick tests of Django projects.

Well here it is:

AMI: ami-0f799d66

Name: Ubuntu 8.10 Django SVN HEAD + Apache2 + mod_python + MySQL 04.12.08

I recommend Right Scale to work with Amazon AWS. It’s great, it’s simple and it’s free!

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