Custom Iterator

Implement a class that can be iterated over using __iter__ and __next__.

IntermediateTopic: Object-Oriented Programs
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Python Custom Iterator Program

This program helps you to learn the fundamental structure and syntax of Python programming.

Try This Code
# Program to implement a custom iterator

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

    def __iter__(self):
        return self

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


for num in Countdown(3):
    print(num)
Output
3
2
1

Understanding Custom Iterator

By defining __iter__ and __next__, Countdown becomes an iterator usable in for-loops.

Note: To write and run Python programs, you need to set up the local environment on your computer. Refer to the complete article Setting up Python Development Environment. If you do not want to set up the local environment on your computer, you can also use online IDE to write and run your Python programs.

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