A newbie question about class
Mark McEahern
marklists at mceahern.com
Sat Feb 9 21:03:40 EST 2002
[newgene]
> Hi, group,
> I have a newbie question about building a class:
>
> eg.
>
> class A:
> def __init__(self,x=None):
> self.x=x
> if self.x != None:
> self.y=x**2
> else:
> self.y=x**2
1. When comparing to None, it's better to use one of the following:
if x is not None:...
if x is None:...
2. Consider using property, which is new with Python 2.2 and requires a
new-style class (thus we subclass from object):
class A(object):
def __init__(self, x=None):
self._x = x
def getX(self):
return self._x
def setX(self, x):
self._x = x
x = property(getX, setX)
a = A(1)
print a.x
Cheers,
// mark
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