I am seeing some results when running urlparse with patch urlparse_empty_bad_arg_deprecation2.patch applied:

>>> urllib.parse.urlparse({})
__main__:1: DeprecationWarning: Use of {} is deprecated
__main__:1: DeprecationWarning: Use of '' is deprecated
ParseResultBytes(scheme=b'', netloc=b'', path=b'', params=b'', query=b'', fragment=b'')

>>> urllib.parse.urlparse('', b'')
__main__:1: DeprecationWarning: Use of b'' is deprecated
/home/poleto/SCMws/python/latest/cpython/Lib/urllib/parse.py:378: DeprecationWarning: Use of b'' is deprecated
  splitresult = urlsplit(url, scheme, allow_fragments)
ParseResult(scheme=b'', netloc='', path='', params='', query='', fragment='')
Will bytes be deprecated if used as a default_schema?

>>> urllib.parse.urlparse(b'', '')
ParseResultBytes(scheme=b'', netloc=b'', path=b'', params=b'', query=b'', fragment=b'')
Shouldn't it complain that the types are different? In fact it does, if you don't provide empty strings:

>>> urllib.parse.urlparse(b'www.python.org', 'http')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "(...)/cpython/Lib/urllib/parse.py", line 377, in urlparse
    url, scheme, _coerce_result = _coerce_args(url, scheme)
  File "(...)/cpython/Lib/urllib/parse.py", line 120, in _coerce_args
    raise TypeError("Cannot mix str and non-str arguments")
TypeError: Cannot mix str and non-str arguments

>>> urllib.parse.urlparse({'a' : 1})
__main__:1: DeprecationWarning: Use of '' is deprecated
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "(...)/cpython/Lib/urllib/parse.py", line 377, in urlparse
    url, scheme, _coerce_result = _coerce_args(url, scheme)
  File "(...)/cpython/Lib/urllib/parse.py", line 128, in _coerce_args
    return _decode_args(args) + (_encode_result,)
  File "(...)/cpython/Lib/urllib/parse.py", line 98, in _decode_args
    return tuple(x.decode(encoding, errors) if x else '' for x in args)
  File "(...)/cpython/Lib/urllib/parse.py", line 98, in <genexpr>
    return tuple(x.decode(encoding, errors) if x else '' for x in args)
AttributeError: 'dict' object has no attribute 'decode'

>>> urllib.parse.urlparse(['a', 'b', 'c'])
__main__:1: DeprecationWarning: Use of [] is deprecated
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "(...)/cpython/Lib/urllib/parse.py", line 377, in urlparse
    url, scheme, _coerce_result = _coerce_args(url, scheme)
  File "(...)/cpython/Lib/urllib/parse.py", line 128, in _coerce_args
    return _decode_args(args) + (_encode_result,)
  File "(...)/cpython/Lib/urllib/parse.py", line 98, in _decode_args
    return tuple(x.decode(encoding, errors) if x else '' for x in args)
  File "(...)/cpython/Lib/urllib/parse.py", line 98, in <genexpr>
    return tuple(x.decode(encoding, errors) if x else '' for x in args)
AttributeError: 'list' object has no attribute 'decode'

I thought about writing test cases but I wasn't a 100% sure if the above is working as expected so I thought I should ask first.