test_fileinput.py 文件源码

def test_readline(self):
        with open(TESTFN, 'wb') as f:
            f.write(b'A\nB\r\nC\r')
            # Fill TextIOWrapper buffer.
            f.write(b'123456789\n' * 1000)
            # Issue #20501: readline() shouldn't read whole file.
            f.write(b'\x80')
        self.addCleanup(safe_unlink, TESTFN)

        with FileInput(files=TESTFN,
                       openhook=hook_encoded('ascii'), bufsize=8) as fi:
            try:
                self.assertEqual(fi.readline(), 'A\n')
                self.assertEqual(fi.readline(), 'B\n')
                self.assertEqual(fi.readline(), 'C\n')
            except UnicodeDecodeError:
                self.fail('Read to end of file')
            with self.assertRaises(UnicodeDecodeError):
                # Read to the end of file.
                list(fi)
            self.assertEqual(fi.readline(), '')
            self.assertEqual(fi.readline(), '')