What are some examples of custom iterable objects in Python?

Can you give me some examples of custom iterable objects in Python?

Sure! A custom iterable object in Python is one that implements the __iter__() method. For example, a class that represents a range of numbers can be an iterable.

Can you show me a code example of a custom iterable?

Absolutely! Here's a simple example:

class Countdown:
    def __init__(self, start):
        self.start = start

    def __iter__(self):
        self.current = self.start
        return self

    def __next__(self):
        if self.current < 0:
            raise StopIteration
        else:
            self.current -= 1
            return self.current + 1

for number in Countdown(5):
    print(number)

What happens if I don't implement the __iter__ method?

If you don't implement the __iter__ method, your object won't be iterable, and trying to use it in a loop or with functions that require an iterable will raise a TypeError.

Can you explain the __next__ method as well?

Certainly! The __next__ method is called to get the next value from the iterator. If there are no more items to return, it should raise a StopIteration exception to signal that the iteration is complete.