Python2: Fix tox -e py27

With this change, unit tests now pass on Python 2.7: tox -e py27.

Changes:

* Replace "yield from ..." with "for item in ...: yield item"
* Remove last annotations from utils.py
* tox.ini: use python3 as basepython rather than python3.5 to support
  Python 2.7 and Python 3.6
* tox.ini: add py27 to envlist

Related-Bug: 1726399
Change-Id: Ief1a95402e8a31a34ada2937a7ae6a604f7f8757

ospurge/resources/swift.py

@@ -30,7 +30,8 @@ class Objects(base.ServiceResource, glance.ListImagesMixin, ListObjectsMixin):
                 self.cloud.list_volume_backups() == [])
 
     def list(self):
-        yield from self.list_objects()
+        for item in self.list_objects():
+            yield item
 
     def delete(self, resource):
         self.cloud.delete_object(resource['container_name'], resource['name'])

ospurge/utils.py

@@ -59,12 +59,12 @@ def monkeypatch_oscc_logging_warning(f):
     oscc_target = 'os_client_config.cloud_config'
     orig_logging = logging.getLogger(oscc_target).warning
 
-    def logging_warning(msg: str, *args, **kwargs):
+    def logging_warning(msg, *args, **kwargs):
         if 'catalog entry not found' not in msg:
             orig_logging(msg, *args, **kwargs)
 
     @functools.wraps(f)
-    def wrapper(*args: list, **kwargs):
+    def wrapper(*args, **kwargs):
         try:
             setattr(logging.getLogger(oscc_target), 'warning', logging_warning)
             return f(*args, **kwargs)

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = pep8,pip-check-reqs,cover,py35
+envlist = pep8,pip-check-reqs,cover,py35,py27
 minversion = 1.9
 skipsdist = True
 
@@ -8,13 +8,12 @@ usedevelop=True
 deps =
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/test-requirements.txt
-basepython =
-    run,pep8,cover,mypy,pip-check-reqs,py35,functional: python3.5
-    docs,venv: python2
+basepython = python3
 commands =
     python setup.py testr --testr-args='{posargs}'
 
 [testenv:venv]
+basepython = python2.7
 commands = {posargs}
 
 [testenv:run]
@@ -60,6 +59,7 @@ commands=
     pip-missing-reqs -d ospurge
 
 [testenv:docs]
+basepython = python2.7
 whitelist_externals = echo
 skip_install = True
 deps =