Iterator that returns the next n numbers as a list.

pager.py

class Pager:
    """Iterator that returns the next n numbers as a list."""

    def __init__(self, set_size=10):
        self.set_size = set_size
        self.start = 1

    def __iter__(self):
        return self

    def __next__(self):
        end = self.start + self.set_size
        page_range = range(self.start, end)
        self.start = end
        return list(page_range)

test_pager.py

import unittest

from pager import Pager

class TestPager(unittest.TestCase):
    def test_return_next_ten_numbers(self):
        """By default the Pager class will return the next 10 numbers"""
        idder = Pager()
        assertion = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
        self.assertEqual(next(idder), assertion)
        second_assertion = [11, 12, 13, 14, 15, 16, 17, 18, 19, 20]
        self.assertEqual(next(idder), second_assertion)
        third_assertion = list(range(21, 31))
        self.assertEqual(next(idder), third_assertion)

    def test_return_dynamic_next_numbers(self):
        """Pager class will return next set of determined size"""
        idder = Pager(set_size=25)
        assertion = list(range(1, 26))  # 1 - 25
        self.assertEqual(next(idder), assertion)
        second_assertion = list(range(26, 51))  # 26 - 50
        self.assertEqual(next(idder), second_assertion)
        third_assertion = list(range(51, 76))  # 51 - 75
        self.assertEqual(next(idder), third_assertion)


if __name__ == '__main__':
    unittest.main()