bpo-42967: coerce bytes separator to string in urllib.parse_qs(l) (GH-24818)

* coerce bytes separator to string * Add news * Update Misc/NEWS.d/next/Library/2021-03-11-00-31-41.bpo-42967.2PeQRw.rst (cherry picked from commit b38601d) Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>

Author: miss-islington

Lib/test/test_urlparse.py

@@ -893,6 +893,8 @@ def test_parse_qs_separator(self):
  with self.subTest(f"Original: {orig!r}, Expected: {expect!r}"):
  result = urllib.parse.parse_qs(orig, separator=';')
  self.assertEqual(result, expect, "Error parsing %r" % orig)
+ result_bytes = urllib.parse.parse_qs(orig, separator=b';')
+ self.assertEqual(result_bytes, expect, "Error parsing %r" % orig)
 
 
  def test_parse_qsl_separator(self):
@@ -912,6 +914,8 @@ def test_parse_qsl_separator(self):
  with self.subTest(f"Original: {orig!r}, Expected: {expect!r}"):
  result = urllib.parse.parse_qsl(orig, separator=';')
  self.assertEqual(result, expect, "Error parsing %r" % orig)
+ result_bytes = urllib.parse.parse_qsl(orig, separator=b';')
+ self.assertEqual(result_bytes, expect, "Error parsing %r" % orig)
 
 
  def test_urlencode_sequences(self):

Lib/urllib/parse.py

@@ -733,6 +733,7 @@ def parse_qsl(qs, keep_blank_values=False, strict_parsing=False,
  Returns a list, as G-d intended.
  """
  qs, _coerce_result = _coerce_args(qs)
+ separator, _ = _coerce_args(separator)
 
  if not separator or (not isinstance(separator, (str, bytes))):
  raise ValueError("Separator must be of type string or bytes.")

Misc/NEWS.d/next/Library/2021-03-11-00-31-41.bpo-42967.2PeQRw.rst

@@ -0,0 +1,3 @@
+Allow :class:`bytes` ``separator`` argument in ``urllib.parse.parse_qs`` and
+``urllib.parse.parse_qsl`` when parsing :class:`str` query strings. Previously,
+this raised a ``TypeError``.