This document discusses using Python on the Java platform. It begins by asking if a Java platform can exist without Java, and explores using Python, Ruby, Scala and Groovy instead. It then highlights features of Python like being dynamic, flexible and readable. Jython is introduced as a way to use Python on the Java platform. The document demonstrates using Swing GUIs from Jython and shows a Django web application example. It also discusses testing Python code including doctests and integration tests using HtmlUnit. Finally, it mentions some companies that use Jython and provides resources for learning more.

1. Python para la Plataforma Java
Leo Soto M.
Encuentro Linux 2009

8. http://www.flickr.com/photos/ferruiz/4036373874/

9. Python para la plataforma Java

10. http://www.flickr.com/photos/lab2112/457187539/

11. ¿Plataforma Java sin Java?

12. Plataforma Java con Java más
Python, Ruby, Scala, Groovy...

13. ¿Por qué Python?

14. “Python is an experiment in how much freedom
programmers need...”

15. “...Too much freedom and nobody can read
another's code; too little and expressiveness is
endangered”
- Guido van Rossum, 1996

16. Python
Dinámico, flexible, extremadamente legible

17. Jython
Dinámico, flexible, extremadamente legible
En una plataforma ubicua, sólida

18. http://www.flickr.com/photos/mushon/282287572/

19. Status de Jython
http://www.flickr.com/photos/digital-noise/3650559857/

20. 2.5.1

21. Full compatibilidad con CPython

22. web2py
etree nose
setuptools virtualenv

23. OK

24. ¿Pero qué puedo hacer con Jython
hoy?

25. GUIs

26. Demo con Swing

27. De Java a Jython

28. final JFrame frame = new JFrame("HelloSwing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,300);

29. frame = JFrame("HelloSwing")
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)
frame.setSize(300,300)

30. frame = JFrame("HelloSwing",
defaultCloseOperation=JFrame.EXIT_ON_CLOSE,
size=(300, 300))

31. Container content = frame.getContentPane();
content.setLayout(new FlowLayout());

32. content = frame.getContentPane();
content.setLayout(new FlowLayout());

33. content = frame.contentPane
content.setLayout(new FlowLayout());

34. content = frame.contentPane
content.setLayout(FlowLayout());

35. content = frame.contentPane
content.layout = FlowLayout()

36. JButton botonSaludar = new JButton("Saludar");
JButton botonDespedir = new JButton("Despedirse");
botonSaludar.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(frame, "Hola!");
}
});
botonDespedir.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(frame, "Chao!");
frame.dispose();
}
});
content.add(botonSaludar);
content.add(botonDespedir);

37. def saludar(event):
JOptionPane.showMessageDialog(frame, "Hola!")
def despedir(event):
JOptionPane.showMessageDialog(frame, "Chao!")
frame.dispose()
content.add(JButton("Saludar", actionPerformed=saludar))
content.add(JButton("Despedirse", actionPerformed=despedir))

38. Otra demo con Swing
(Si es que tenemos acceso a internet)

39. Créditos: Frank Wierzbicki

40. Web

41. Demo con Django

42. Y sólo por diversión...

43. ### View
#!/usr/bin/env python
from django import http
"""
from django.template import Template, Context
WSW - the World's Shittiest Wiki.
"""
def wsw(request, title):
import re
title = urllib.unquote_plus(title) if title else "Home"
import urllib
p, created = Page.objects.get_or_create(title=title)
from django.conf import settings
form = PageForm(instance=p)
if request.method == "POST":
### Config
form = PageForm(request.POST, instance=p)
settings.configure(
form.save()
DEBUG = True,
return http.HttpResponseRedirect(request.get_full_path())
DATABASE_ENGINE = "doj.backends.zxjdbc.postgresql",
else:
DATABASE_NAME = "wsw",
form = PageForm(instance=p)
DATABASE_USER = "wsw",
t = Template("""<h1>{{ p.title }}</h1><ul>{% for p in
DATABASE_PASSWORD = "wsw",
allpages %}<li><a href="{{ p }}">{{ p }}</a></li>{% endfor %}
ROOT_URLCONF = __name__)
</ul><form action="{{ request.get_full_path }}" method="POST">
<p>{{ form.content }}</p><input type="submit"></form>""")
### Model
wikiwords = re.findall(
from django.db import models
'[A-Z][a-z]+[A-Z][a-z]+(?:[A-Z][a-z]+)*', p.content)
allpages = [
class Page(models.Model):
page.title for page in Page.objects.order_by('title')]
title = models.CharField(max_length=300,
allpages.extend(
primary_key=True)
word for word in wikiwords if word not in allpages)
content = models.TextField()
return http.HttpResponse(t.render(Context(locals())))
class Meta:
### Main
app_label = "wsw"
if __name__ == '__main__':
from django.core import management
### URLs
from django.db import connection
from django.conf.urls.defaults import *
from django.core.management.color import no_style
cursor = connection.cursor()
urlpatterns = patterns(__name__, ('(.*)', 'wsw'))
statements, _ = connection.creation.sql_create_model(
Page, no_style())
### Form
try:
from django.forms import ModelForm
for sql in statements:
cursor.execute(sql)
class PageForm(ModelForm):
connection.connection.commit()
class Meta:
except:
model = Page
pass
fields = ['content']
management.call_command('runserver')

44. Créditos: Jacob Kaplan-Moss

45. Testing
http://www.flickr.com/photos/emotionaltoothpaste/26034597/

46. DocTests

47. def factorial(n):
It must also not be ridiculously large:
"""Return the factorial of n, an
>>> factorial(1e100)
exact integer >= 0.
Traceback (most recent call last):
...
If the result is small enough to
OverflowError: n too large
fit in an int, return an int.
"""
Else return a long.
import math
>>> [factorial(n)
if not n >= 0:
... for n in range(6)]
raise ValueError("n must be >= 0")
[1, 1, 2, 6, 24, 120]
if math.floor(n) != n:
>>> [factorial(long(n))
raise ValueError(
... for n in range(6)]
"n must be exact integer")
[1, 1, 2, 6, 24, 120]
if n+1 == n: # catch a value like 1e300
>>> factorial(30)
raise OverflowError("n too large")
265252859812191058636308480000000L
result = 1
>>> factorial(30L)
factor = 2
265252859812191058636308480000000L
while factor <= n:
>>> factorial(-1)
result *= factor
Traceback (most recent call last):
factor += 1
...
return result
ValueError: n must be >= 0
Factorials of floats are OK, but
the float must be an exact integer:
>>> factorial(30.1)
Traceback (most recent call last):
...
ValueError: n must be exact integer
>>> factorial(30.0)
265252859812191058636308480000000L

48. Demo: DocTests + HtmlUnit

49. Demo: DocTests + HtmlUnit
¿Ah?

50. ¡Tests de Integración para web apps!

51. Oh, para eso tenemos Selenium, ¿no?

53. Ejecutar en el browser tarda muuuuucho
http://www.flickr.com/photos/tambako/498552755/

54. Run headless...

55. Run headless...
...con HtmlUnit!

56. Demo: DocTests + HtmlUnit

57. Más Testing
http://www.flickr.com/photos/emotionaltoothpaste/26034597/

60. ¿Por cierto, quien más usa Jython?

64. EADS
http://www.flickr.com/photos/nguyendai/694158734/

65. Lockheed Martin
http://www.flickr.com/photos/rcsj/2504022678/

66. ¿Y dónde puedo aprender más?

67. jythonbook.com

68. jythonbook.com

69. ¡Gracias!
Contacto:
@leosoto
http://blog.leosoto.com

70. ¿Preguntas?
Contacto:
@leosoto
http://blog.leosoto.com