345449.vhj5l3oj7.asia
ShapeFactory1.py
2001-12-26T16:00:00Z
2001-12-26T16:00:00Z
<br/><TEXTAREA name="code" class="py" rows="16" cols="100">#: c05:shapefact1:ShapeFactory1.py
# A simple static factory method.
from __future__ import generators
import random
class Shape(object):
# Create based on class name:
def factory(type):
#return eval(type + "()")
if type == "Circle": return Circle()
if type == "Square": return Square()
assert 1, "Bad shape creation: " + type
factory = staticmethod(factory)
class Circle(Shape):
def draw(self): print "Circle.draw"
def erase(self): print "Circle.erase"
class Square(Shape):
def draw(self): print "Square.draw"
def erase(self): print "Square.erase"
# Generate shape name strings:
def shapeNameGen(n):
types = Shape.__subclasses__()
for i in range(n):
yield random.choice(types).__name__
shapes = \
[ Shape.factory(i) for i in shapeNameGen(7)]
for shape in shapes:
shape.draw()
shape.erase()
#:~</TEXTAREA><br><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script>
2001-12-26T16:00:00Z