instantiating dynamic class

gistfile1.txt

if i use this loop outside of def build(self): i get this: kivy.factory.FactoryException: Unknown class <TravelerBtn>  
if i change the widget in the for loop to 'Button,' i get 24 buttons in the stacklayout with the propertext.
if i use the loop within 'def build (self):', i can't set the text value of the  <TravelerBtn> instances.


def build (self):

    for i in range(25):
    i = Factory.TravelerBtn(text =str(i))
    rootwidget.add_widget(i)

return rootwidget

here is the kv rule:

<TravelerBtn@BoxLayout>:
    size_hint: (None, None)
    size: (200, 200)
    text: 'None'
    canvas.before:
        Color:
            rgba: (1, 0, 0, 1)
        Rectangle:
            pos: self.pos
            size: self.size
    Button:
        size_hint: (None, None)
        size: (180, 180)
        text: root.text