Referring to class methods in class attributes

[Jean-Michel Pichavant]

mk wrote:
> Stephen Hansen wrote:
>
>> You don't have to (and can't) refer to the class within the body. 
>> Class statements are sort of... odd. They are code which is directly 
>> executed, and the results are then passed into a 
>> metaclass/type/whatever and a class object is created. While within 
>> the class body, the class doesn't exist yet.
>>
>> But you don't need it to.
>>
>> Just do:
>>
>>    'internal_date': print_internal_date
>>
>> The 'def' is in the same local scope as 'tagdata' is.
>
> Thanks, that worked. But in order to make it work I had to get rid of 
> 'self' in print_internal_date signature, bc all other functions in 
> tagdata have only a single argument:
>
> class PYFileInfo(FileInfo):
>     'python file properties'
>
>     def print_internal_date(filename):
> ...
>
>     tagdata = {'compiled_fname': lambda x: x + 'c',
>                 'size': os.path.getsize,
>                 'internal_date': print_internal_date
>             }
>
> That looks weird: a method with no 'self'. Hmm that is probably 
> seriously wrong.
> [snip]


Absolutely not. It's called a static method, you have to decorate it 
with @staticmethod though.

class A:
    @staticmethod
    def getInstance():
       return A()

a = A.getInstance()

you have also the class method version:

class B:
    @classmethod:
    def getInstance(cls): # class methods take a class as first parameter
       return cls()


JM