Add pyupgrade to pre-commit and update syntax to Python3.7+

.pre-commit-config.yaml

@@ -80,3 +80,9 @@ repos:
         name: isort-examples
         args: [--settings=examples]
         files: '^examples/'
+
+  - repo: https://github.com/asottile/pyupgrade
+    rev: v2.34.0
+    hooks:
+    -   id: pyupgrade
+        args: [--py37-plus]

_importlinter_conditional.py

@@ -80,7 +80,7 @@ def _check_secured_import(self, mod: str, lno: int) -> bool:
         # Some hard-coded heuristics because importlib fails on circular imports.
         # TODO: switch to: importlib.util.find_spec(mod)?.origin
         path = os.path.join(os.path.dirname(__file__), mod.replace('.', '/')) + '.py'
-        with open(path, 'rt', encoding='utf-8') as f:
+        with open(path, encoding='utf-8') as f:
             text = f.read()
             xtree = astpath.file_contents_to_xml_ast(text)
 

examples/13-hooks/example.py

@@ -59,12 +59,12 @@ async def login_fn(**kwargs):
 
 @kopf.on.probe()
 async def tasks_count(**kwargs):
-    return sum([len(flags) for flags in STOPPERS.values()])
+    return sum(len(flags) for flags in STOPPERS.values())
 
 
 @kopf.on.probe()
 async def monitored_objects(**kwargs):
-    return {namespace: sorted([name for name in STOPPERS[namespace]]) for namespace in STOPPERS}
+    return {namespace: sorted(name for name in STOPPERS[namespace]) for namespace in STOPPERS}
 
 
 @kopf.on.event('pods')

kopf/_cogs/helpers/hostnames.py

@@ -15,7 +15,7 @@ def get_descriptive_hostname() -> str:
     """
     try:
         hostname, aliases, ipaddrs = socket.gethostbyaddr(socket.gethostname())
-    except socket.error:
+    except OSError:
         pass
     else:
         ipv4: Optional[ipaddress.IPv4Address]

kopf/_core/intents/piggybacking.py

@@ -173,12 +173,12 @@ def login_with_service_account(**_: Any) -> Optional[credentials.ConnectionInfo]
     ca_path = '/var/run/secrets/kubernetes.io/serviceaccount/ca.crt'
 
     if os.path.exists(token_path):
-        with open(token_path, 'rt', encoding='utf-8') as f:
+        with open(token_path, encoding='utf-8') as f:
             token = f.read().strip()
 
         namespace: Optional[str] = None
         if os.path.exists(ns_path):
-            with open(ns_path, 'rt', encoding='utf-8') as f:
+            with open(ns_path, encoding='utf-8') as f:
                 namespace = f.read().strip()
 
         return credentials.ConnectionInfo(
@@ -226,7 +226,7 @@ def login_with_kubeconfig(**_: Any) -> Optional[credentials.ConnectionInfo]:
     users: Dict[Any, Any] = {}
     for path in paths:
 
-        with open(path, 'rt', encoding='utf-8') as f:
+        with open(path, encoding='utf-8') as f:
             config = yaml.safe_load(f.read()) or {}
 
         if current_context is None:

kopf/_core/reactor/inventory.py

@@ -64,8 +64,7 @@ def __init__(self) -> None:
         self._items = {}
 
     def iter_all_memories(self) -> Iterator[ResourceMemory]:
-        for memory in self._items.values():
-            yield memory
+        yield from self._items.values()
 
     def iter_all_daemon_memories(self) -> Iterator[daemons.DaemonsMemory]:
         for memory in self._items.values():

tests/cli/test_help.py

@@ -1,5 +1,3 @@
-
-
 def test_help_in_root(invoke, mocker):
     result = invoke(['--help'])
 

tests/conftest.py

@@ -561,7 +561,7 @@ def timer():
     return Timer()
 
 
-class Timer(object):
+class Timer:
     """
     A helper context manager to measure the time of the code-blocks.
     Also, supports direct comparison with time-deltas and the numbers of seconds.

tests/e2e/conftest.py

@@ -10,7 +10,7 @@
 root_dir = os.path.relpath(os.path.dirname(os.path.dirname(os.path.dirname(__file__))))
 examples = sorted(glob.glob(os.path.join(root_dir, 'examples/*/')))
 assert examples  # if empty, it is just the detection failed
-examples = [path for path in examples if not glob.glob((os.path.join(path, 'test*.py')))]
+examples = [path for path in examples if not glob.glob(os.path.join(path, 'test*.py'))]
 
 
 @pytest.fixture

tests/e2e/test_examples.py

@@ -134,7 +134,7 @@ class E2EParser:
     def __init__(self, path: str) -> None:
         super().__init__()
 
-        with open(path, 'rt', encoding='utf-8') as f:
+        with open(path, encoding='utf-8') as f:
             self.path = path
             self.text = f.read()
 

tests/hierarchies/conftest.py

@@ -8,8 +8,7 @@ def __init__(self, objs):
         self._objs = objs
 
     def __iter__(self):
-        for obj in self._objs:
-            yield obj
+        yield from self._objs
 
 
 @pytest.fixture(params=[list, tuple, CustomIterable],

tests/reactor/test_queueing.py

@@ -157,10 +157,10 @@ async def test_watchevent_batching(settings, resource, processor, timer,
     assert processor.call_count == len(uids)
     assert processor.call_count == len(vals)
     expected_uid_val_pairs = set(zip(uids, vals))
-    actual_uid_val_pairs = set((
+    actual_uid_val_pairs = {(
             kwargs['raw_event']['object']['metadata']['uid'],
             kwargs['raw_event']['object']['spec'])
-            for args, kwargs in processor.call_args_list)
+            for args, kwargs in processor.call_args_list}
     assert actual_uid_val_pairs == expected_uid_val_pairs
 
 

tests/test_it.py

@@ -1,5 +1,3 @@
-
-
 def test_importing_works():
     import kopf
     assert kopf

tests/timing/test_throttling.py

@@ -158,7 +158,7 @@ async def test_renews_on_repeated_failure(sleep):
     async with throttled(throttler=throttler, logger=logger, delays=[234]):
         raise Exception()
 
-    assert throttler.last_used_delay is 234
+    assert throttler.last_used_delay == 234
     assert throttler.source_of_delays is not None
     assert throttler.active_until is None
     assert sleep.mock_calls == [call(234, wakeup=None)]