There is a problem with python 3.8 and escape sequence:

There is a problem with python 3.8 and escape sequence: 'invalid escape sequence \*

________________________ ERROR collecting test session _________________________
/opt/virtualenvs/py38/lib/python3.8/site-packages/py/_path/common.py:383: in visit
    for x in Visitor(fil, rec, ignore, bf, sort).gen(self):
/opt/virtualenvs/py38/lib/python3.8/site-packages/py/_path/common.py:435: in gen
    for p in self.gen(subdir):
/opt/virtualenvs/py38/lib/python3.8/site-packages/py/_path/common.py:435: in gen
    for p in self.gen(subdir):
/opt/virtualenvs/py38/lib/python3.8/site-packages/py/_path/common.py:424: in gen
    dirs = self.optsort([p for p in entries
/opt/virtualenvs/py38/lib/python3.8/site-packages/py/_path/common.py:425: in <listcomp>
    if p.check(dir=1) and (rec is None or rec(p))])
/opt/virtualenvs/py38/lib/python3.8/site-packages/_pytest/main.py:667: in _recurse
    ihook = self.gethookproxy(dirpath)
/opt/virtualenvs/py38/lib/python3.8/site-packages/_pytest/main.py:482: in gethookproxy
    my_conftestmodules = pm._getconftestmodules(fspath)
/opt/virtualenvs/py38/lib/python3.8/site-packages/_pytest/config/__init__.py:431: in _getconftestmodules
    mod = self._importconftest(conftestpath.realpath())
/opt/virtualenvs/py38/lib/python3.8/site-packages/_pytest/config/__init__.py:470: in _importconftest
    raise ConftestImportFailure(conftestpath, sys.exc_info())
E   _pytest.config.ConftestImportFailure: (local('/conftest.py'), (<class 'SyntaxError'>, SyntaxError('invalid escape sequence \\*', ('/opt/virtualenvs/py38/lib/python3.8/site-packages/requests_oauthlib/oauth1_session.py', 258, 9, '        """Fetch a request token.\n')), <traceback object at 0x7fee844d6140>))

_Originally posted by @matejsp in https://github.com/requests/requests-oauthlib/issues/443#issuecomment-954664334_

[jtroussard]

This doc string is flagged as a raw string, and that seems to be the fix for this warning. See stackoverflow link…

def fetch_request_token(self, url, realm=None, **request_kwargs):
        r"""Fetch a request token.

        This is the first step in the OAuth 1 workflow. A request token is
        obtained by making a signed post request to url. The token is then
        parsed from the application/x-www-form-urlencoded response and ready
        to be used to construct an authorization url.

        :param url: The request token endpoint URL.
        :param realm: A list of realms to request access to.
        :param \*\*request_kwargs: Optional arguments passed to ''post''
        ..."""

https://stackoverflow.com/questions/52335970/how-to-fix-string-deprecationwarning-invalid-escape-sequence-in-python

and more insight into this patch https://bugs.python.org/issue27364

I think we are safe to say that this issue has been covered.

[matejsp]

Trying with sample test.py and current python that I use. It is not the same but similar behaviour.

test.py

def test_me():
    """ some \*\* """ 
    print("ok")

pytest test.py

(env39) ➜  ~ pytest test.py
=============================================================================================================== test session starts ================================================================================================================
platform darwin -- Python 3.9.9, pytest-4.6.11, py-1.10.0, pluggy-0.13.1
Using --random-order-bucket=module
Using --random-order-seed=93520

rootdir: /Users/user
plugins: freezegun-0.4.2, mock-1.11.2, metadata-1.10.0, random-order-0.8.1+bts1, celery-4.4.7, cov-2.11.1, django-3.10.0, html-1.22.1, forked-1.3.0, xdist-1.27.0
collected 1 item                                                                                                                                                                                                                                   

test.py .                                                                                                                                                                                                                                    [100%]

================================================================================================================= warnings summary =================================================================================================================
test.py:2
  /Users/user/test.py:2: DeprecationWarning: invalid escape sequence \*
    """ some \*\* """

-- Docs: https://docs.pytest.org/en/latest/warnings.html
======================================================================================================= 1 passed, 1 warnings in 0.06 seconds =======================================================================================================
(env39) ➜  ~