How do I test generators in Python?

How do I test generators in Python?

You can test generators in Python using the unittest framework or by using the pytest library. Would you like an example?

Yes, please provide an example using unittest.

Sure! Here's a simple example:

import unittest

def my_generator():
    yield 1
    yield 2
    yield 3

class TestMyGenerator(unittest.TestCase):
    def test_generator(self):
        gen = my_generator()
        self.assertEqual(next(gen), 1)
        self.assertEqual(next(gen), 2)
        self.assertEqual(next(gen), 3)

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

This tests that the generator yields the expected values.

What if I want to test if the generator raises an exception?

You can use the assertRaises method in your test case. For example:

def my_generator_with_exception():
    yield 1
    raise ValueError('An error occurred')

class TestMyGeneratorWithException(unittest.TestCase):
    def test_generator_exception(self):
        gen = my_generator_with_exception()
        next(gen)  # This should yield 1
        with self.assertRaises(ValueError):
            next(gen)  # This should raise the exception