Can a child access parent attributes if that child added post-hoc as an attribute to the parent?
So I have a parent and child class:
class Map(object):
def __init__(self, name=''):
self.mapName = name
self.rules = {}
class Rule(Map):
def __init__(self, number):
Map.__init__(self)
self.number = number
def __repr__(self):
return "Map " + self.mapName + " rule number " + str(self.number)
if __name__ == "__main__":
map = Map("thismap")
rule = Rule(1)
map.rules[rule.number] = rule
with the above:
$ python -i inherit.py
>>> map
<__main__.Map object at 0xb7e889ec>
>>> map.rules
{1: Map rule number 1}
>>> map.rules[1]
Map rule number 1
>>>
I have tried adding:
map.rules[2] = Rule(2)
but that still gets:
$ python -i inherit.py
>>> map.rules
{1: Map rule number 1, 2: Map rule number 2}
>>>
and:
map.rule = Rule(3)
which also doesn't really get me what I'm looking for:
>>> map.rules
{1: Map rule number 1, 2: Map rule number 2}
>>> map.rule
Map rule number 3
>>>
It seems to me what I'm trying to do is link an arbitrary child instance to an
arbitrary instance of a parent class, which in this case would be handy
Because I'd like to populate a map with rules and print the rules including the
parent map name for each rule. I'm just not sure how I would go about doing
this in python.
Any thoughts are welcome, and thanks in advance
--
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Re: Can a child access parent attributes if that child added post-hoc as an attribute to the parent?
On Thursday, August 22, 2013 4:26:24 PM UTC-5, Prasad, Ramit wrote:
> Bitswapper wrote:
>
> >
>
> > So I have a parent and child class:
>
> >
>
> >
>
> > class Map(object):
>
> > def __init__(self, name=''):
>
> > self.mapName = name
>
> > self.rules = {}
>
> >
>
> > class Rule(Map):
>
> > def __init__(self, number):
>
> > Map.__init__(self)
>
> > self.number = number
>
>
>
> This means that rules will never have a name. I think you need
>
> def __init__(self, name='', number=None):
>
> Map.__init__(self, name)
>
> self.number = number
>
> >
>
> > def __repr__(self):
>
> > return "Map " + self.mapName + " rule number " + str(self.number)
>
> >
>
> > if __name__ == "__main__":
>
> > map = Map("thismap")
>
> > rule = Rule(1)
>
> > map.rules[rule.number] = rule
>
> >
>
> >
>
> >
>
> > with the above:
>
> > $ python -i inherit.py
>
> > >>> map
>
> > <__main__.Map object at 0xb7e889ec>
>
> > >>> map.rules
>
> > {1: Map rule number 1}
>
> > >>> map.rules[1]
>
> > Map rule number 1
>
> > >>>
>
> >
>
> >
>
> > I have tried adding:
>
> > map.rules[2] = Rule(2)
>
> >
>
> > but that still gets:
>
> >
>
> > $ python -i inherit.py
>
> > >>> map.rules
>
> > {1: Map rule number 1, 2: Map rule number 2}
>
> > >>>
>
> >
>
> > and:
>
> > map.rule = Rule(3)
>
> >
>
> > which also doesn't really get me what I'm looking for:
>
> >
>
> > >>> map.rules
>
> > {1: Map rule number 1, 2: Map rule number 2}
>
> > >>> map.rule
>
> > Map rule number 3
>
> > >>>
>
> >
>
> >
>
> > It seems to me what I'm trying to do is link an arbitrary child instance to
> > an arbitrary instance of a
>
> > parent class, which in this case would be handy Because I'd like to
> > populate a map with rules and
>
> > print the rules including the parent map name for each rule. I'm just not
> > sure how I would go about
>
> > doing this in python.
>
> >
>
> > Any thoughts are welcome, and thanks in advance
>
>
>
> I not sure what you mean by the above. Can you provide an example of what you
> want to occur and the output for it?
>
I was thinking of:
map = Map('myMap')
map.rules[1] = Rule[1]
map.rules[2] = Rule[2]
>>> print map.rules[1]
>>> Map myMap rule number 1
>>> print map.rules[2]
>>> Map myMap rule number 2
>>>
>>> map.mapName = "newname"
>>> print map.rules[1]
>>> Map newname rule number 1
>>> print map.rules[2]
>>> Map newname rule number 2
--
http://mail.python.org/mailman/listinfo/python-list
Re: Can a child access parent attributes if that child added post-hoc as an attribute to the parent?
On Thursday, August 22, 2013 5:00:38 PM UTC-5, Bitswapper wrote:
> On Thursday, August 22, 2013 4:26:24 PM UTC-5, Prasad, Ramit wrote:
>
> > Bitswapper wrote:
>
> >
>
> > >
>
> >
>
> > > So I have a parent and child class:
>
> >
>
> > >
>
> >
>
> > >
>
> >
>
> > > class Map(object):
>
> >
>
> > > def __init__(self, name=''):
>
> >
>
> > > self.mapName = name
>
> >
>
> > > self.rules = {}
>
> >
>
> > >
>
> >
>
> > > class Rule(Map):
>
> >
>
> > > def __init__(self, number):
>
> >
>
> > > Map.__init__(self)
>
> >
>
> > > self.number = number
>
> >
>
> >
>
> >
>
> > This means that rules will never have a name. I think you need
>
> >
>
> > def __init__(self, name='', number=None):
>
> >
>
> > Map.__init__(self, name)
>
> >
>
> > self.number = number
>
> >
>
> > >
>
> >
>
> > > def __repr__(self):
>
> >
>
> > > return "Map " + self.mapName + " rule number " + str(self.number)
>
> >
>
> > >
>
> >
>
> > > if __name__ == "__main__":
>
> >
>
> > > map = Map("thismap")
>
> >
>
> > > rule = Rule(1)
>
> >
>
> > > map.rules[rule.number] = rule
>
> >
>
> > >
>
> >
>
> > >
>
> >
>
> > >
>
> >
>
> > > with the above:
>
> >
>
> > > $ python -i inherit.py
>
> >
>
> > > >>> map
>
> >
>
> > > <__main__.Map object at 0xb7e889ec>
>
> >
>
> > > >>> map.rules
>
> >
>
> > > {1: Map rule number 1}
>
> >
>
> > > >>> map.rules[1]
>
> >
>
> > > Map rule number 1
>
> >
>
> > > >>>
>
> >
>
> > >
>
> >
>
> > >
>
> >
>
> > > I have tried adding:
>
> >
>
> > > map.rules[2] = Rule(2)
>
> >
>
> > >
>
> >
>
> > > but that still gets:
>
> >
>
> > >
>
> >
>
> > > $ python -i inherit.py
>
> >
>
> > > >>> map.rules
>
> >
>
> > > {1: Map rule number 1, 2: Map rule number 2}
>
> >
>
> > > >>>
>
> >
>
> > >
>
> >
>
> > > and:
>
> >
>
> > > map.rule = Rule(3)
>
> >
>
> > >
>
> >
>
> > > which also doesn't really get me what I'm looking for:
>
> >
>
> > >
>
> >
>
> > > >>> map.rules
>
> >
>
> > > {1: Map rule number 1, 2: Map rule number 2}
>
> >
>
> > > >>> map.rule
>
> >
>
> > > Map rule number 3
>
> >
>
> > > >>>
>
> >
>
> > >
>
> >
>
> > >
>
> >
>
> > > It seems to me what I'm trying to do is link an arbitrary child instance
> > > to an arbitrary instance of a
>
> >
>
> > > parent class, which in this case would be handy Because I'd like to
> > > populate a map with rules and
>
> >
>
> > > print the rules including the parent map name for each rule. I'm just
> > > not sure how I would go about
>
> >
>
> > > doing this in python.
>
> >
>
> > >
>
> >
>
> > > Any thoughts are welcome, and thanks in advance
>
> >
>
> >
>
> >
>
> > I not sure what you mean by the above. Can you provide an example of what
> > you want to occur and the output for it?
>
> >
>
>
>
> I was thinking of:
>
>
>
> map = Map('myMap')
>
> map.rules[1] = Rule(1)
>
> map.rules[2] = Rule(2)
>
>
>
> >>> print map.rules[1]
>
> >>> Map myMap rule number 1
>
> >>> print map.rules[2]
>
> >>> Map myMap rule number 2
>
> >>>
>
> >>> map.mapName = "newname"
>
> >>> print map.rules[1]
>
> >>> Map newname rule number 1
>
> >>> print map.rules[2]
>
> >>> Map newname rule number 2
Or rather:
map = Map('myMap')
map.rules[1] = Rule(1)
map.rules[2] = Rule(2)
>>> print map.rules[1]
>>> Map myMap rule number 1
>>> print map.rules[2]
>>> Map myMap rule number 2
>>>
>>> map.mapName = "newname"
>>> print map.rules[1]
>>> Map newname rule number 1
>>> print map.rules[2]
>>> Map newname rule number 2
--
http://mail.python.org/mailman/listinfo/python-list
Re: Can a child access parent attributes if that child added post-hoc as an attribute to the parent?
On Thursday, August 22, 2013 4:59:17 PM UTC-5, Ian wrote:
> On Thu, Aug 22, 2013 at 3:26 PM, Prasad, Ramit
>
> <> wrote:
>
> > Bitswapper wrote:
>
> >>
>
> >> So I have a parent and child class:
>
> >>
>
> >>
>
> >> class Map(object):
>
> >> def __init__(self, name=''):
>
> >> self.mapName = name
>
> >> self.rules = {}
>
> >>
>
> >> class Rule(Map):
>
> >> def __init__(self, number):
>
> >> Map.__init__(self)
>
> >> self.number = number
>
> >
>
> > This means that rules will never have a name. I think you need
>
> > def __init__(self, name='', number=None):
>
> > Map.__init__(self, name)
>
> > self.number = number
>
>
>
> No, that's still wrong. The OP talks abut maps having names, not
>
> rules having names. Unless a Rule is-a Map, which sounds unlikely,
>
> Rule should not be inheriting from Map in the first place.
>
>
>
> >> It seems to me what I'm trying to do is link an arbitrary child instance
> >> to an arbitrary instance of a
>
> >> parent class, which in this case would be handy Because I'd like to
> >> populate a map with rules and
>
> >> print the rules including the parent map name for each rule. I'm just not
> >> sure how I would go about
>
> >> doing this in python.
>
>
>
> You'll need to keep a reference to the Map on each Rule instance. So
>
> instead of self.mapName you'll have self.map.mapName. Your Rule class
>
> should probably look something like this:
>
>
>
> class Rule(object):
>
> def __init__(self, map, number):
>
> self.map = map
>
> self.number = number
>
>
>
> And then when you construct it you'll need to tell it what map it belongs to:
>
>
>
> rule = Rule(map, 1)
Actually yea, that makes sense. I was looking for a way for a child to
'automagically' inherit parent instance-specific data via inheritance only by
virtue of being a child of a parent instance. What you're suggesting makes
more sense.
Thanks!
--
http://mail.python.org/mailman/listinfo/python-list
