Esmail wrote:
I am just reading about properties in Python. I am thinking
of this as an indirection mechanism, is that wrong? If so, how
come the getter/setters aren't called when I use properties
instead of the functions directly?
Because you weren't actually using them. You were writing:
size = 3, 7
not:
r.size = 3, 7
Try:
class Rectangle(object):
def __init__(self):
self._width = 0 # use single underscore unless you
self._height = 0 # have a serious reason for __x
def setSize(self, shape): # a setter takes a single arg
width, height = shape
print 'in setter'
if width < 0 or height < 0:
print >> sys.stderr, 'Negative values not allowed'
else:
self._width = width
self._height = height
def getSize(self):
print 'in getter'
return self._width, self._height
size = property(getSize, setSize)
r = Rectangle()
print r.getSize()
r.setSize((-40, 30))
print r.getSize()
print '-----------------'
r.size = 3, 7
print r.size
print '-----------------'
r.size = -3,7
print r.size
--Scott David Daniels
scott.dani...@acm.org
--
http://mail.python.org/mailman/listinfo/python-list
