Error when calling superclass __init__ method

[Maese Fernando]

Hi,

I'm getting an odd error while trying to call the __init__ method of a
super class:

BaseField.__init__(self)
TypeError: unbound method __init__() must be called with BaseField
instance as first argument (got nothing instead)


This is the code:

class BaseField(object):

def _addFieldsToRec(self, rec, *fields):
for field in fields:
self.mfn[field] = rec

def __init__(self):
self._addFieldsToRec(1,1)
self._addFieldsToRec(2, 500,501,502,503,504,505,506,507,508)


class Field(BaseField):
def __init__(self, value):
BaseField.__init__(self)  # this seems to be the offending
line.
self.tag = value


What am I doing wrong?
--
http://mail.python.org/mailman/listinfo/python-list

Re: Error when calling superclass __init__ method

[Peter Otten]

Maese Fernando wrote:

 I'm getting an odd error while trying to call the __init__ method of a
 super class:
 
 BaseField.__init__(self)
 TypeError: unbound method __init__() must be called with BaseField
 instance as first argument (got nothing instead)
 
 
 This is the code:

No, it isn't. Please provide the actual code or, better, a minimal
example. Don't forget to run it to verify it shows the behaviour described
above before you post it.

 What am I doing wrong?

My bets are on

BaseField.__init__() # no self

Peter
--
http://mail.python.org/mailman/listinfo/python-list

calling superclass __init__ when superclass is object

[Evan Klitzke]

Hi list,

I was reading this article: http://fuhm.net/super-harmful/ and didn't
understand the comment about calling super(Foo, self).__init__() when
Foo inherits only from object. Can someone on the list elaborate more
on why one should do this?

-- 
Evan Klitzke [EMAIL PROTECTED]
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: calling superclass __init__ when superclass is object

[Evan Klitzke]

On 8/1/07, Evan Klitzke [EMAIL PROTECTED] wrote:
 Hi list,

 I was reading this article: http://fuhm.net/super-harmful/ and didn't
 understand the comment about calling super(Foo, self).__init__() when
 Foo inherits only from object. Can someone on the list elaborate more
 on why one should do this?

I hate to reply to my own thread, but I read this article:
http://www.python.org/download/releases/2.3/mro/ and I think I
understand the rationale now. If you have:

class Foo(object):
# stuff here
class Bar(object):
# stuff here
class Baz(Foo, Bar):
# stuff here

Then if Baz calls super(Baz, self).__init__() in its __init__, and Foo
makes no call super(Foo, self).__init__(), then the constructor for
Bar will never be called.

-- 
Evan Klitzke [EMAIL PROTECTED]
-- 
http://mail.python.org/mailman/listinfo/python-list

Calling superclass

[Florian Lindner]

Hello,
I try to call the superclass of the ConfigParser object:

class CustomizedConfParser(ConfigParser.SafeConfigParser):
def get(self, section, attribute):
try:
return super(CustomizedConfParser, self).get(section, attribute)
# [...]


but that gives only

return super(CustomizedConfParser, self).get(section, attribute)
TypeError: super() argument 1 must be type, not classobj

I don't really understand the error message.

Thanks,

Florian

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Calling superclass

[Diez B. Roggisch]

Florian Lindner wrote:

 Hello,
 I try to call the superclass of the ConfigParser object:
 
 class CustomizedConfParser(ConfigParser.SafeConfigParser):
 def get(self, section, attribute):
 try:
 return super(CustomizedConfParser, self).get(section,
 attribute)
 # [...]
 
 
 but that gives only
 
 return super(CustomizedConfParser, self).get(section, attribute)
 TypeError: super() argument 1 must be type, not classobj
 
 I don't really understand the error message.


super works only for newstyle-classes. So additionally extend
CustomizedConfParser from object.

diez
-- 
http://mail.python.org/mailman/listinfo/python-list