Converted to python3 / BytesIO form, the tests pass

request_iter_lines_test.py

import unittest
import requests
from io import BytesIO
print(requests.__file__)


class TestIterLines(unittest.TestCase):

    def iter_lines_response(self, chunk_size, delimiter=None):
        response = requests.Response()
        response.raw = BytesIO(b'01\r\n45')
        gen = response.iter_lines(chunk_size=chunk_size, delimiter=delimiter)
        result = list(gen)
        self.assertEqual(result, [b'01', b'45'])

    def test_splitlines_before_delimiter(self): self.iter_lines_response(2)

    def test_splitlines_in_delimiter(self): self.iter_lines_response(3)

    def test_splitlines_after_delimiter(self): self.iter_lines_response(4)

    def test_splitlines_in_line(self): self.iter_lines_response(5)

    def test_split_before_delimiter(self): self.iter_lines_response(2, b'\r\n')

    def test_split_in_delimiter(self): self.iter_lines_response(3, b'\r\n')

    def test_split_after_delimiter(self): self.iter_lines_response(4, b'\r\n')

    def test_split_in_line(self): self.iter_lines_response(5, b'\r\n')
      
# all pass