sábado, 28 de junio de 2008

hola mundo!!! en python

Esta es mi primera incursión en el lenguaje python, y por medio del famoso hola mundo podremos adentrarnos a la sintaxis de este exelente lenguaje. Para implementarlo podemos hacerlo de dos formas, una es usando el interprete de python, linea a linea, para ello colocamos el siguiente texto, print "hola mundo!!", y le damos enter.

La otra forma es, escribiendo la sintaxis print "hola mundo!!!" en un documento de texto y guardamos con extención .py, por ejemplo hola.py, para ejecutar el archivo, abrimos una consola y nos ubicamos en la carpeta en donde se encuentre hola.py, ahi escribimos, python hola.py

Esto es la forma mas simple, con el uso de una consola, ahora vamos a ver como es el hola mundo, empleando los recursos de gtk, y de esta manera se podra obtener, un mensaje con interfaz grafica, por lo que se empleará un codigo un poco mas completo, que es el siguiente que coloco aqui:

import pygtk
pygtk.require('2.0')
import gtk

class HelloWorld:

# This is a callback function. The data arguments are ignored
# in this example. More on callbacks below.
def hello(self, widget, data=None):
print "Hello World"

def delete_event(self, widget, event, data=None):
# If you return FALSE in the "delete_event" signal handler,
# GTK will emit the "destroy" signal. Returning TRUE means
# you don't want the window to be destroyed.
# This is useful for popping up 'are you sure you want to quit?'
# type dialogs.
print "delete event occurred"

# Change FALSE to TRUE and the main window will not be destroyed
# with a "delete_event".
return gtk.FALSE

# Another callback
def destroy(self, widget, data=None):
gtk.main_quit()

def __init__(self):
# create a new window
self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)

# When the window is given the "delete_event" signal (this is given
# by the window manager, usually by the "close" option, or on the
# titlebar), we ask it to call the delete_event () function
# as defined above. The data passed to the callback
# function is NULL and is ignored in the callback function.
self.window.connect("delete_event", self.delete_event)

# Here we connect the "destroy" event to a signal handler.
# This event occurs when we call gtk_widget_destroy() on the window,
# or if we return FALSE in the "delete_event" callback.
self.window.connect("destroy", self.destroy)

# Sets the border width of the window.
self.window.set_border_width(10)

# Creates a new button with the label "Hello World".
self.button = gtk.Button("Hello World")

# When the button receives the "clicked" signal, it will call the
# function hello() passing it None as its argument. The hello()
# function is defined above.
self.button.connect("clicked", self.hello, None)

# This will cause the window to be destroyed by calling
# gtk_widget_destroy(window) when "clicked". Again, the destroy
# signal could come from here, or the window manager.
self.button.connect_object("clicked", gtk.Widget.destroy, self.window)

# This packs the button into the window (a GTK container).
self.window.add(self.button)

# The final step is to display this newly created widget.
self.button.show()

# and the window
self.window.show()

def main(self):
# All PyGTK applications must have a gtk.main(). Control ends here
# and waits for an event to occur (like a key press or mouse event).
gtk.main()

# If the program is run directly or passed as an argument to the python
# interpreter then create a HelloWorld instance and show it
if __name__ == "__main__":
hello = HelloWorld()
hello.main()

Como dije un poco mas completo, y mas interesante para comprender a python, codigos, que parece mas un algoritmo :).


http://mundogeek.net/archivos/2008/01/16/mi-primer-programa-en-python/