import datetime
d=[]
class TTT():

    class rrr():

        def hhh(self, w):
            global d
##            print 'f'
            d.append (w)
            return

    def R(self, f):
        self.rrr.hhh (f)  ##Здесь выдаёт ошибку:
                              ##TypeError: unbound method hhh() must be called with rrr instance as first argument (got str instance instead)


dddd=TTT()
dddd.R('rrr')
dddd.R('sss')