set default python to python3

Set the default python to python3 except for the py27 environment. We
have to set that explicitly to override the new default.

Have py27 and py3* jobs run same commands by removing the commands entry
for py27.

The pep8 rules under python 3 are different, so we need to fix a
couple of issues with blank space. The E721 rule is ignored entirely
because we are not yet using a version of flake8 that supports
ignoring individual rules on specific lines, although the instructions
for that are added so that when we upgrade flake8 to a newer version
we can remove the global rule.

Change-Id: Id236b0632a83a188958130d04f1e9c476c5ace65
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

4 files changed, 9 insertions, 10 deletions

diff --git a/taskflow/conductors/backends/impl_executor.py b/taskflow/conductors/backends/impl_executor.py
index 2dc2ddd..99c3e5e 100644
--- a/taskflow/conductors/backends/impl_executor.py
+++ b/taskflow/conductors/backends/impl_executor.py
@@ -180,7 +180,7 @@ class ExecutorConductor(base.Conductor):
                                                (engine.prepare, 'preparation'),
                                                (engine.validate, 'validation'),
                                                (_run_engine, 'running')]:
-                    self._notifier.notify("%s_start" % event_name,  details)
+                    self._notifier.notify("%s_start" % event_name, details)
                     stage_func()
                     self._notifier.notify("%s_end" % event_name, details)
             except excp.WrappedFailure as e:
diff --git a/taskflow/engines/worker_based/engine.py b/taskflow/engines/worker_based/engine.py
index 52a30f6..52ba35e 100644
--- a/taskflow/engines/worker_based/engine.py
+++ b/taskflow/engines/worker_based/engine.py
@@ -82,4 +82,4 @@ class WorkerBasedActionEngine(engine.ActionEngine):
                                                pr.REQUEST_TIMEOUT),
                 worker_expiry=options.get('worker_expiry',
                                           pr.EXPIRES_AFTER),
-                )
+            )
diff --git a/taskflow/types/failure.py b/taskflow/types/failure.py
index b798a5d..ccdcea0 100644
--- a/taskflow/types/failure.py
+++ b/taskflow/types/failure.py
@@ -54,7 +54,10 @@ def _are_equal_exc_info_tuples(ei1, ei2):
     # copy_exc_info above.
     if ei1[0] is not ei2[0]:
         return False
-    if not all((type(ei1[1]) == type(ei2[1]),
+    # NOTE(dhellmann): The flake8/pep8 error E721 does not apply here
+    # because we want the types to be exactly the same, not just have
+    # one be inherited from the other.
+    if not all((type(ei1[1]) == type(ei2[1]),  # noqa: E721
                 _exception_message(ei1[1]) == _exception_message(ei2[1]),
                 repr(ei1[1]) == repr(ei2[1]))):
         return False
diff --git a/tox.ini b/tox.ini
index d4c420a..fa4214b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,6 +10,7 @@ envlist = cover,
     update-states
 
 [testenv]
+basepython = python3
 setenv = VIRTUAL_ENV={envdir}
          BRANCH_NAME=master
          CLIENT_NAME=taskflow
@@ -50,6 +51,7 @@ commands = {posargs}
 [flake8]
 builtins = _
 exclude = .venv,.tox,dist,doc,*egg,.git,build,tools
+ignore = E721
 
 [hacking]
 import_exceptions = six.moves
@@ -64,19 +66,13 @@ import_exceptions = six.moves
 ignore-path = doc/*/target,doc/*/build*
 
 [testenv:py27]
-deps = .[test,workers,zookeeper,database,redis,eventlet]
-      -r{toxinidir}/doc/requirements.txt
-commands =
-    python setup.py testr --slowest --testr-args='{posargs}'
-    sphinx-build -b doctest doc/source doc/build
-    doc8 --ignore-path "doc/source/history.rst" doc/source
+basepython = python2.7
 
 [testenv:releasenotes]
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:lower-constraints]
-basepython = python3
 install_command = pip install {opts} {packages}
 deps =
   -c{toxinidir}/lower-constraints.txt