Run pyupgrade to clean up Python 2 syntaxes

Update all .py source files by
 $ pyupgrade --py3-only $(git ls-files | grep ".py$")
to modernize the code according to Python 3 syntaxes.

Also introduce pre-commit and its pyupgrade hook to avoid merging
additional Python 2 syntaxes.

Change-Id: If182808de2e565028998b3ed45947d267d6e021c

.pre-commit-config.yaml

@@ -0,0 +1,30 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      # Replaces or checks mixed line ending
+      - id: mixed-line-ending
+        args: ['--fix', 'lf']
+        exclude: '.*\.(svg)$'
+      # Forbid files which have a UTF-8 byte-order marker
+      - id: check-byte-order-marker
+      # Checks that non-binary executables have a proper shebang
+      - id: check-executables-have-shebangs
+      # Check for files that contain merge conflict strings.
+      - id: check-merge-conflict
+      # Check for debugger imports and py37+ breakpoint()
+      # calls in python source
+      - id: debug-statements
+      - id: check-yaml
+        files: .*\.(yaml|yml)$
+  - repo: https://opendev.org/openstack/hacking
+    rev: 7.0.0
+    hooks:
+      - id: hacking
+        additional_dependencies: []
+  - repo: https://github.com/asottile/pyupgrade
+    rev: v3.18.0
+    hooks:
+      - id: pyupgrade
+        args: [--py3-only]

doc/source/conf.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at

oslobot/plugins/oslobot/oslobot.py

@@ -38,7 +38,7 @@ def str_split(text):
     return text.split()
 
 
-class GoogleShortener(object):
+class GoogleShortener:
     """Shortener that uses google shortening service (requires api key).
 
     See: https://developers.google.com/url-shortener/v1/
@@ -58,7 +58,7 @@ class GoogleShortener(object):
     def safe_shorten(self, long_url):
         try:
             return self.shorten(long_url)
-        except (IOError, ValueError, TypeError):
+        except (OSError, ValueError, TypeError):
             self.log.exception("Failed shortening due to unexpected error, "
                                " providing back long url.")
             return long_url
@@ -78,12 +78,12 @@ class GoogleShortener(object):
                                 headers={'content-type': 'application/json'},
                                 timeout=self.timeout)
         except requests.Timeout:
-            raise IOError("Unable to shorten '%s' url"
+            raise OSError("Unable to shorten '%s' url"
                           " due to http request timeout being"
                           " reached" % (long_url))
         else:
             if req.status_code != http_client.OK:
-                raise IOError("Unable to shorten '%s' url due to http"
+                raise OSError("Unable to shorten '%s' url due to http"
                               " error '%s' (%s)" % (long_url, req.reason,
                                                     req.status_code))
             try:
@@ -91,7 +91,7 @@ class GoogleShortener(object):
                 self.cache[long_url] = small_url
                 return small_url
             except (KeyError, ValueError, TypeError) as e:
-                raise IOError("Unable to shorten '%s' url due to request"
+                raise OSError("Unable to shorten '%s' url due to request"
                               " extraction error: %s" % (long_url, e))
 
 
@@ -159,7 +159,7 @@ class OsloBotPlugin(BotPlugin):
         if not configuration:
             configuration = {}
         configuration.update(copy.deepcopy(self.DEF_CONFIG))
-        super(OsloBotPlugin, self).configure(configuration)
+        super().configure(configuration)
         self.log.debug("Bot configuration: %s", self.config)
         self.executor = None
 
@@ -392,12 +392,12 @@ class OsloBotPlugin(BotPlugin):
         return copy.deepcopy(self.DEF_CONFIG)
 
     def deactivate(self):
-        super(OsloBotPlugin, self).deactivate()
+        super().deactivate()
         if self.executor is not None:
             self.executor.shutdown()
 
     def activate(self):
-        super(OsloBotPlugin, self).activate()
+        super().activate()
         self.executor = futures.ThreadPoolExecutor(
             max_workers=self.DEF_FETCH_WORKERS)
         try:

test-requirements.txt

@@ -1 +0,0 @@
-hacking>=6.1.0,<6.2.0 # Apache-2.0

tools/list_oslo_projects.py

@@ -29,7 +29,7 @@ def main():
     gov_repo = os.path.expanduser(os.path.join(conf.repo_root,
                                                'governance'))
     project_input = os.path.join(gov_repo, 'reference/projects.yaml')
-    with open(project_input, 'r') as f:
+    with open(project_input) as f:
         project = yaml.safe_load(f.read())
 
     repos = []

tox.ini

@@ -13,7 +13,10 @@ commands =
     {toxinidir}/tools/list_oslo_projects.py {posargs}
 
 [testenv:pep8]
-commands = flake8
+deps =
+  pre-commit
+commands =
+  pre-commit run -a
 
 [testenv:bashate]
 deps = bashate