Daniel Santos a écrit :
Here goes,
I have a base class that is the following :
class primitive:
pep08 : class names should be Capitalized.
Also, if you're using Python 2.x, make it:
class Primitive(object):
#...
def __init__(self):
self.name = ""
self.transforms = []
def copyInternalState(self, sourceObj, copyName):
pep08 : methods, attributes and variables names should be all_lower
return null
s/null/None/g
def copy(self, copyName):
# copy the source object internal state
primitiveCopy = self.copyInternalState(self, copyName)
# copy the transformations
primitiveCopy.transforms = []
If copyInternalState is supposed to return an instance of a
(well-behaved) subclass of 'primitive' - or any object conforming to the
(implicit) 'primitive' interface, you shouldn't have to do this.
if self.transforms != []:
An empty list has a false value in a boolean test, so the above test
would be better written as :
if self.transforms:
But anyway, the whole test is plain useless:
for item in []:
print "you won't see me"
for transf in self.transforms:
primitiveCopy.transforms.append(transf.copy())
return primitiveCopy
# more methods. the ones listed should be enough to get the picture
And a derived class,
class CircularCilinder(primitive):
def __init__(self, name):
self.name = name
self.baseCenterVertex = [0, 0, 0]
self.heightVertex = [0, 1, 0]
self.radius = 1
You're not calling the __init__ method of primitive. Your code here
should be:
def __init__(self, name):
super(CircularCilinder, self).__init__(name)
self.baseCenterVertex = [0, 0, 0]
self.heightVertex = [0, 1, 0]
self.radius = 1
def copyInternalState(self, sourceObj, copyName):
copy = CircularCilinder(copyName)
copy.setHeight(self.heightVertex[1])
copy.setRadius(self.radius)
Python is not Java. We have good support for computed properties, so you
*don't* need explicit getters/setters - just start with a plain
attribute access, you can always turn it into a computed one latter if
and when the need arises.
return copy
I then have a script that creates a CircularCilinder,
cilinder = CircularCilinder("cilinder")
cilinderCopy = cilinder.copy("cilinderCopy")
when I run this script I get the error,
Traceback (most recent call last):
File "./testscript.py", line 26, in <module>
cilinderCopy = cilinder.copy("cilinderCopy")
File "/cygdrive/d/cg/brlcad_api/trunk/src/ds_brlcad_modeler/api/primitive.py",
line 64, in copy
if self.transforms != []:
AttributeError: CircularCilinder instance has no attribute 'transforms'
Indeed - you didn't call the superclass's __init__
the transforms instance attribute is not known in the derived class. But I
wanted to avoid adding a self.transforms = [] line to the derived class
__init__ method.
Should be the same wrt/ the 'name' attribute FWIW.
HTH
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