import unittest

class TestFull(unittest.TestCase):
    def check_write(self, *lines):
        with open('/dev/full', 'w', 1) as f:
            for line in lines:
                f.write(line)

    def test_write1(self):
        self.assertRaises(IOError, self.check_write, 'hello\n')

    def test_write2(self):
        self.assertRaises(IOError, self.check_write, 'hello', '\n')

unittest.main()