Iterator : next channel calling on a remote control

 #iterator will repeat something.

#going through a data list set one by one is called iterating through a loop. here is the code:

a = ["hi", "how", "are", "you", "boss"]
for i in a:
    print(i)

#output

hi
how
are
you
boss 

#here is how to actually iterate in a program using __iter__ to make a remote control that calls next channel.
class RemoteControl():
    def __init__(self):
        self.channels = ["HBO","cnn","abc","espn"] #listing the channels to iterate through
        self.index = -1 #index indicates the current channel. here, "-1 means TV off"

    def __iter__(self): #calling the iteration method 
        return self

    def __next__(self): #calling the next method to iterate through the self.channels list
        self.index += 1 #everytime add 1 to go to the next channel
        if self.index == len(self.channels): #if self.index is the last channel
            raise StopIteration #then raise StopIteration method. 

        return self.channels[self.index] #or else, return the channel. self.index will take value from next method.

r = RemoteControl()
itr=iter(r)
print(next(itr))
print(next(itr))
print(next(itr))
print(next(itr))
print(next(itr))