def __init__(self, listOfChoices, pick_action, **kwargs):
result = super(DropDownPicker, self).__init__(**kwargs)
self._pick_action = pick_action
pickerList = DropDown()
for item in listOfChoices:
choiceButton = Button(text=item, size_hint_y=None, height=50)
choiceButton.bind(on_release=lambda btn: pickerList.select(btn.text))
pickerList.add_widget(choiceButton)
self.bind(on_release=pickerList.open)
pickerList.bind(on_select=lambda instance, x: self._after_pick(x))
pickerList.size_hint = (None, 0.4)
return result
