# coding: utf-8

class Page(object):
    tpl = '/page'
    @classmethod
    def reg(cls):
        def add(s):
            return cls.tpl + s
        from some import reg
        reg(cls.add)

class Blog(Page):
    tpl = '/blog'

Page.reg()

# coding: utf-8

_methods = []

def regmethod(method):
    _methods.append(method)

class Page(object):
    tpl = '/page/'
    @staticmethod
    def add(cls,s):
        return cls.tpl + s
    @classmethod
    def reg(cls):
        def _add(s):
            return cls.add(cls,s)
        #from some import reg
        regmethod(_add)
        print 'Page.reg'

class Blog(Page):
    tpl = '/blog/'
    @staticmethod
    def add(cls,s):
        return cls.tpl + 'foo/' + s

Blog.reg()
print _methods[0]('test')

class page(object):
    tpl='page'
    @classmethod
    def add(cls, tpl): cls.tpl+=tpl

class blog(page):
    add, tpl=None, 'blog'
    @classmethod
    def add(cls, tpl): cls.tpl+='++'+tpl

>>> page.tpl, blog.tpl
('page', 'blog')
>>> page.add, blog.add
(<bound method type.add of <class '__main__.page'>>, <bound method type.add of <class '__main__.blog'>>)
>>> page.add('sssss'), blog.add('dddd')
(None, None)
>>> page.tpl, blog.tpl
('pagesssss', 'blog++dddd')
>>>

    @classmethod
    def reg(cls):
        regmethod(_add)

class page(object):
    tpl='page'
    @classmethod
    def add(cls, tpl): cls.tpl+=tpl

class blog(page):
    tpl='blog'
    @classmethod
    def reg(cls, func): cls.add=classmethod(func)

def test(cls, tpl): cls.tpl+='/+/'

>>> page.add('1')
>>> blog.add('2')
>>> page.tpl, blog.tpl
('page/1', 'blog/2')
>>> blog.reg(test)
>>> blog.add('3')
>>> page.add('4')
>>> page.tpl, blog.tpl
('page/1/4', 'blog/2/+/3')
>>>

_methods = []

class page():
    tpl = 'page'
    def reg(cls):
        _methods.append( cls.add )
class blog(page):
   tpl = 'blog'
    def add(self,msg):
        return self.tpl+msg

blog.reg()
print _method[0]('hello')