On Feb 4, 4:45 pm, "Mizipzor" <[EMAIL PROTECTED]> wrote:
> I have some troubles with a member variable that seems to be missing
> in a class. In short, heres what I do; class A is the parent class, B
> inherits from A and C inherits from B (hope I used the right words
> there). Now, I create an instance of C, which calls A's __init__ which
> in turn creates all the member variables. Then I call C.move() (a
> function defined in A), but then, one of the variables seems to have
> become 'NoneType'.
>
> The code can be found here (Ive taken away unnecessery
> stuff):http://pastebin.com/875394
>
> The exact error is (which occur on line 15 in the pasted code):
> TypeError: unsupported operand type(s) for *: 'NoneType' and 'float'
>
> Any comments are welcome. :)
Here's a suggestion: use new-style classes. Have _BaseEntity inherit
from object, allows you to use super for invoking methods on super
classes. Instead of:
class Entity(_BaseEntity):
def __init__(self, type, x = 0, y = 0):
_BaseEntity.__init__(self, type, x, y)
You enter:
class Entity(_BaseEntity):
def __init__(self, type, x = 0, y = 0):
super(Entity,self).__init__(type, x, y)
This makes it easier to update your inheritance hierarchy later. New-
style classes have other benefits too.
As for your NoneType problem, try adding "print self._direction" to
the end of _BaseElement.__init__.
-- Paul
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