Inheritance problem

[Mr.SpOOn]

Hi,
I have a problem with this piece of code:


class NoteSet(Ordered Set):
def has_pitch(self) :
pass
def has_note(self):
pass

class Scale(NoteSet):
def __init__(self, root, type):
self.append(roo t)
self.type = type
ScaleType(scale =self)

OrderedSet is an external to use ordered sets. And it has an append
method to append elements to the set.

When I try to create a Scale object:

s = Scale(n, '1234567') # n is a note

I get this error:

Traceback (most recent call last):
File "notes.py", line 276, in <module>
s = Scale(n, '1234567')
File "notes.py", line 243, in __init__
self.append(roo t)
File "ordered_set.py ", line 78, in append
self._insertatn ode(self._end.p rev, element)
AttributeError: 'Scale' object has no attribute '_end'

I can't understand where the error is.
Can you help me?

Thanks,
Carlo

[Diez B. Roggisch]

Re: Inheritance problem

Mr.SpOOn wrote:

Hi,
I have a problem with this piece of code:
>
>
class NoteSet(Ordered Set):
def has_pitch(self) :
pass
def has_note(self):
pass
>
class Scale(NoteSet):
def __init__(self, root, type):
self.append(roo t)
self.type = type
ScaleType(scale =self)
>
OrderedSet is an external to use ordered sets. And it has an append
method to append elements to the set.
>
When I try to create a Scale object:
>
s = Scale(n, '1234567') # n is a note
>
I get this error:
>
Traceback (most recent call last):
File "notes.py", line 276, in <module>
s = Scale(n, '1234567')
File "notes.py", line 243, in __init__
self.append(roo t)
File "ordered_set.py ", line 78, in append
self._insertatn ode(self._end.p rev, element)
AttributeError: 'Scale' object has no attribute '_end'
>
I can't understand where the error is.
Can you help me?

You need to call the __init__ of NoteSet inside Scale, as otherwise the
instance isn't properly initialized.

class Scale(NoteSet):
def __init__(self, root, type):
super(Scale, self).__init__( )
...

or
NoteSet.__init_ _(self)

if you have an old-style class.

Diez

[Mr.SpOOn]

Re: Inheritance problem

On Wed, Nov 5, 2008 at 6:59 PM, Diez B. Roggisch <deets@nospam.w eb.dewrote:

You need to call the __init__ of NoteSet inside Scale, as otherwise the
instance isn't properly initialized.

Thanks, solved.