Trying to use a list comprehension for RecycleView data in kv.

recyc_test.py

from kivy.app import App
from kivy.lang import Builder
from kivy.properties import DictProperty, ListProperty, StringProperty
from kivy.uix.boxlayout import BoxLayout


class Viewclass(BoxLayout):
    k = StringProperty()
    v = StringProperty()


class RecycTest(BoxLayout):
    data = DictProperty()
    sorted_keys = ListProperty()


class RecycTestApp(App):
    def build(self):
        return RecycTest(
            data={'spam': 'delicious', 'eggs': 'undelicious', 'ham': 'sickening'},
            sorted_keys=['ham', 'eggs', 'spam']
        )


Builder.load_string("""
#:import RecycleView recycleview.RecycleView
<Viewclass>:
    orientation: 'horizontal'
    Label:
        text: root.k
    Label:
        text: root.v
<RecycTest>:
    RecycleView:
        data: [{'index': i, 'viewclass': 'Viewclass', 'k': root.sorted_keys[i], 'v': root.data[root.sorted_keys[i]]} for i in xrange(len(root.sorted_keys))]
""")


if __name__ == '__main__':
    RecycTestApp().run()