Python and Cairo – There will be blood…
What will a huge Hollywood fan do after Daniel Day Lewis won Best actor award for “There will be Blood” beating legendary actor like George Cluny..? Well, he will definitely watch “There will be blood”. But as that film hasn’t yet released in India, I decided to do something which is no way related to that movie.. Learn to do something interesting with Cairo in Python…
As I was thrilled about the movie- “there will be blood”, I decided to create a simple GTK animation which shows the spreading of blood in the floor.. obviously insipired from the name of the movie 
Python code
#########################################################################
#
#PyCairo Demo:- There will be blood ..
#By Maxin B. John
#An animation to show the capabilites of PyCairo
#
# About Cairo
# Cairo is a software library used to provide a vector graphics based,
# device-independent API for software developers. It is designed to provide
# primitives for 2-dimensional drawing across a number of different backends.
#Cairo is designed to use hardware acceleration when available.
# #########################################################################
#!/usr/bin/env python
import sys
import gobject
import pygtk
pygtk.require(’2.0′)
import gtk
from gtk import gdk
import cairo
if gtk.pygtk_version < (2,10,0):
print “PyGtk 2.10.0 or later required”
raise SystemExit
win = None
#The blood is a circle filled with red color whose radius grows with time
def expose(widget, event):
global radius
cr= widget.window.cairo_create()
cr.set_source_rgba(1.0, 0, 0, 0.7)
cr.arc(float(radius)/2, float(radius)/2, radius, 0, 2.0*3.14)
cr.fill()
cr.stroke()
return True
# this keeps the blood flowing…
def update_clock():
global win
global radius
radius = radius +1
win.queue_draw()
return True
# the ‘main’ function
def main(args):
global win
global radius
radius =0
win = gtk.Window()
win.set_app_paintable(True)
win.set_title(‘PyCairo Demo’)
win.connect(‘delete-event’, gtk.main_quit)
win.connect(‘expose-event’, expose)
gobject.timeout_add(100, update_clock)
win.show_all()
gtk.main()
return True
# The pythonic way to start the animation
if __name__ == ‘__main__’:
sys.exit(main(sys.argv))
And the output 
Don’t you feel the smell of blood… ??? 