Kivy/Python Countdown App project kivy has no attribute 'built' error

Question

Question: What is a 'has no attribute 'built' error, and what do I need to do to correct this code so that it can take in a datetime object and display the count down? Sorry for the long post.

I've provided the code and a link to the .kv file .

I tried to create a countdown clock that takes a datetime object as a parameter and counts down to that date (using python and kivy). It's basically an slight adaptation of Adam Giermanowski 's countdown timer tutorial.

Here's my code:

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import StringProperty
from kivy.clock import Clock
import datetime

#datetime object
b= datetime.datetime(2016,9,12,3,5)

class Counter_Timer(BoxLayout):
    days = StringProperty()
    hours = StringProperty()
    minutes = StringProperty()
    seconds = StringProperty()

    def __init__(self, datetimeOBJ):
        self.datetimeOBJ = datetimeOBJ

    def update(self, dt):
        #the difference in time
        delta = self.datetimeOBJ - datetime.datetime.now()
        self.days = str(delta.days)
        hour_string = str(delta).split(', ')[1]
        self.hours = hour_string.split(':')[0]
        self.minutes = hour_string.split(':')[1]
        self.seconds = hour_string.split(':')[2].split('.')[0]


class Counter(App):
    #takes a datetime object as a parameter 
    def __init__(self, datetimeOBJ):
        self.datetimeOBJ = datetimeOBJ 

    def build(self):
        Counter = Counter_Timer(self.datetimeOBJ)
        Clock.schedule_interval(Counter.update, 1.0)
        return Counter

if __name__=='__main__':
    Counter(b).run()

Here's the error on the Counter(b).run() line:

AttributeError: 'Counter' object has no attribute 'built'

Answer 1

You have to call the superclasses constructor when you override __init__ , so that all of the things that that constructor does in order to have the other methods of the class work gets done. Your init method should be this:

def __init__(self, datetimeOBJ):
    App.init(self)
    self.datetimeOBJ = datetimeOBJ