On 9/18/13 7:54 PM, Peter Cacioppi wrote:
This is a very old topic, but here is a trick for single inheritance. (The
problem you allude to isn't restricted to multiple inheritance).
Any class with a single parent simply defines this function.
def mySuper(self) :
return super(self.__class__, self)
And then any parent function be referenced like
self.mySuper().foo()
You can't use self.__class__ for super, it won't give you the right
class if you are using subclasses:
class MyBase(object):
def mySuper(self):
return super(self.__class__, self)
def say(self):
print "This is MyBase!"
class Thing(MyBase):
def say_it(self):
print "The parent:"
self.mySuper().say()
def say(self):
print "this is Thing!"
class SubThing(Thing):
pass
thing = Thing()
thing.say_it()
sub = SubThing()
sub.say_it()
This produces:
The parent:
This is MyBase!
The parent:
this is Thing!
super() takes a class and an instance for a reason. If you could use
self.__class__ for the class, then it would only take the instance.
Super() needs to know the instance, but also needs to know the class
it's being called from.
--Ned.
This includes __init__.
You can read more here.
http://atlee.ca/blog/posts/blog20081121python-reload-danger-here-be-dragons.html
On Thursday, March 21, 2002 2:03:23 PM UTC-7, Marc wrote:
I have classes defined in different files and would like to inherit
from a class in file A.py for a class in file B.py but am running into
problems. I'm using Python 1.5.2 on Windows NT
Here's a specific example:
************************
file cbase01.py:
class CBase:
def __init__(self):
self.cclass = None
print "cbase"
class CImStream(CBase):
def __init(self):
CBase.__init__(self)
print "CImStream"
*************************
in file wrappers_A01.py:
import cbase01
reload(cbase01)
class ImStream_SavedBitmaps(cbase01.CImStream):
def __init__(self):
cbase.CImStream.__init__(self)
print "SavedBitmaps"
**************************
in file sequencer01.py
import cbase01 # the offending lines, program works
reload(cbase01) # if I comment these out.
class Sequencer:
def Append(self, item):
pass
*****************************
in test02.py
import wrappers_A01
reload(wrappers_A01)
import sequencer01
reload(sequencer01)
x0 = wrappers_A01.ImStream_SavedBitmaps()
***************************************************************
If I run test02 I get the traceback
Traceback (innermost last):
File "<string>", line 1, in ?
File "D:\PythonCode\pna\eyeTracking\tests\test02.py", line 15, in ?
x0 = wrappers_A01.ImStream_SavedBitmaps()
File "D:\PythonCode\pna\eyeTracking\tests\wrappers_A01.py", line 21,
in __init__
cbase.CImStream.__init__(self)
TypeError: unbound method must be called with class instance 1st
argument
Any ideas what I am doing wrong?
Thanks,
Marc
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