iterators.py

class It:
    """An example of iterators."""

    def __init__(self, max_, start=1, increment=1):
        self.max_ = max_
        self.start = start
        self.increment = increment
        self.counter = self.start - self.increment

    def __iter__(self):
        return self

    def __next__(self):
        self.counter += self.increment
        if self.counter > self.max_:
            raise StopIteration
        return self.counter


it = It(101, 7, 3)
for i in it:
    print(i)


class Fibonacci:
    """Fibonacci sequence implementation."""

    def __init__(self, max_):
        self.max_ = max_
        self.current = 0
        self.next = 1

    def __iter__(self):
        return self

    def __next__(self):
        self.current, self.next = self.next, self.current + self.next
        if self.current > self.max_:
            raise StopIteration
        return self.current


fib = Fibonacci(12000)
for itm in fib:
    print(itm)