Migrate from pendulum to arrow for dates

Changelog

@@ -1,8 +1,9 @@
-Version 0.6.10    unreleased
+Version 0.7.0     unreleased
 
 	* Migrate to Poetry v2 and project-managed Poetry plugins.
 	* Move configuration into pyproject.toml for pytest, mypy & coverage.
 	* Upgrade to gha-shared-workflows@v8 for Poetry v2 support.
+	* Migrate from pendulum to arrow for dates (interface change).
 	* Update all dependencies and outdated constraints.
 
 Version 0.6.9     02 Jan 2025

pyproject.toml

@@ -43,13 +43,13 @@ license = "Apache-2.0"
 readme = "PyPI.md"
 dynamic = [ "classifiers", "version" ]
 dependencies = [
-   "pendulum (>=3.0.0,<4.0.0)",
    "attrs (>=24.2.0,<25.0.0)",
    "cattrs (>=24.1.2,<25.0.0)",
    "PyYAML (>=6.0.1,<7.0.0)",
    "pycryptodomex (>=3.19.0,<4.0.0)",
    "requests (>=2.31.0,<3.0.0)",
    "tenacity (>=9.0.0,<10.0.0)",
+   "arrow (>=1.3.0,<2.0.0)",
 ]
 
 [project.urls]

src/smartapp/converter.py

@@ -9,11 +9,12 @@
 from typing import Any, Dict, Type, TypeVar
 
 import yaml
+from arrow import Arrow
+from arrow import get as arrow_get
+from arrow import now as arrow_now
 from attrs import fields, has
 from cattrs import GenConverter
 from cattrs.gen import make_dict_structure_fn, make_dict_unstructure_fn, override
-from pendulum import from_format, now
-from pendulum.datetime import DateTime
 
 from .interface import (
     CONFIG_SETTING_BY_TYPE,
@@ -29,36 +30,36 @@
 
 DATETIME_ZONE = "UTC"
 
-DATETIME_SEC_EPOCH = "1970-01-01T00:00:00Z"  # date of the UNIX epoch, which sometimes seem to mean "no date"
+DATETIME_SEC_EPOCH = "1970-01-01T00:00:00Z"  # date of the UNIX epoch, which sometimes seems to mean "no date"
 DATETIME_SEC_LEN = len("YYYY-MM-DDTHH:MM:SSZ")  # like "2017-09-13T04:18:12Z"
 DATETIME_SEC_FORMAT = "YYYY-MM-DD[T]HH:mm:ss[Z]"
 
-DATETIME_MS_EPOCH = "1970-01-01T00:00:00.000Z"  # date of the UNIX epoch, which sometimes seem to mean "no date"
+DATETIME_MS_EPOCH = "1970-01-01T00:00:00.000Z"  # date of the UNIX epoch, which sometimes seems to mean "no date"
 DATETIME_MS_LEN = len("YYYY-MM-DDTHH:MM:SS.SSSZ")  # like "2017-09-13T04:18:12.992Z"
 DATETIME_MS_FORMAT = "YYYY-MM-DD[T]HH:mm:ss.SSS[Z]"
 
 T = TypeVar("T")  # pylint: disable=invalid-name:
 
 
-def serialize_datetime(datetime: DateTime) -> str:
-    """Serialize a DateTime to a string."""
+def serialize_datetime(datetime: Arrow) -> str:
+    """Serialize an Arrow datetime to a string."""
     # Note that we always use the full millisecond timestamp here and always convert to UTC
-    return datetime.in_timezone(DATETIME_ZONE).format(DATETIME_MS_FORMAT)  # type: ignore[no-untyped-call,no-any-return,unused-ignore]
+    return datetime.to(DATETIME_ZONE).format(DATETIME_MS_FORMAT)
 
 
-def deserialize_datetime(datetime: str) -> DateTime:
-    """Deserialize a string into a DateTime."""
+def deserialize_datetime(datetime: str) -> Arrow:
+    """Deserialize a string into an Arrow datetime."""
     # Dates from SmartThings are not as reliable as I had hoped.  The samples show a
     # format including milliseconds.  Actual data (at least sometimes) comes without
     # milliseconds.  Further, some requests come with a UNIX epoch date (1970-01-01) which
     # I guess is probably what happens when no date was set by the device.  I'm choosing
     # to interpret that as "now".
     if datetime in (DATETIME_MS_EPOCH, DATETIME_SEC_EPOCH):
-        return now()
+        return arrow_now()
     elif len(datetime) == DATETIME_MS_LEN:
-        return from_format(datetime, DATETIME_MS_FORMAT, tz=DATETIME_ZONE)
+        return arrow_get(datetime, DATETIME_MS_FORMAT, tzinfo=DATETIME_ZONE)
     elif len(datetime) == DATETIME_SEC_LEN:
-        return from_format(datetime, DATETIME_SEC_FORMAT, tz=DATETIME_ZONE)
+        return arrow_get(datetime, DATETIME_SEC_FORMAT, tzinfo=DATETIME_ZONE)
     else:
         raise ValueError("Unknown datetime format: %s" % datetime)
 
@@ -118,18 +119,18 @@ class SmartAppConverter(StandardConverter):
 
     def __init__(self) -> None:
         super().__init__()
-        self.register_unstructure_hook(DateTime, self._unstructure_datetime)
-        self.register_structure_hook(DateTime, self._structure_datetime)
+        self.register_unstructure_hook(Arrow, self._unstructure_datetime)
+        self.register_structure_hook(Arrow, self._structure_datetime)
         self.register_structure_hook(ConfigValue, self._structure_config_value)
         self.register_structure_hook(ConfigSetting, self._structure_config_setting)
         self.register_structure_hook(LifecycleRequest, self._structure_request)
 
-    def _unstructure_datetime(self, datetime: DateTime) -> str:
-        """Serialize a DateTime to a string."""
+    def _unstructure_datetime(self, datetime: Arrow) -> str:
+        """Serialize an Arrow datetime to a string."""
         return serialize_datetime(datetime)
 
-    def _structure_datetime(self, datetime: str, _: Type[DateTime]) -> DateTime:
-        """Deserialize a string into a DateTime."""
+    def _structure_datetime(self, datetime: str, _: Type[Arrow]) -> Arrow:
+        """Deserialize a string into an Arrow datetime."""
         return deserialize_datetime(datetime)
 
     def _structure_config_value(self, data: Dict[str, Any], _: Type[ConfigValue]) -> ConfigValue:

src/smartapp/interface.py

@@ -28,8 +28,8 @@
 from enum import Enum
 from typing import Any, Callable, Dict, List, Mapping, Optional, Union
 
+from arrow import Arrow
 from attrs import field, frozen
-from pendulum.datetime import DateTime
 
 AUTHORIZATION_HEADER = "authorization"
 CORRELATION_ID_HEADER = "x-st-correlation"
@@ -362,7 +362,7 @@ def as_float(self, key: str) -> float:
 class Event:
     """Holds the triggered event, one of several different attributes depending on event type."""
 
-    event_time: Optional[DateTime] = None
+    event_time: Optional[Arrow] = None
     event_type: EventType
     device_event: Optional[Dict[str, Any]] = None
     device_lifecycle_event: Optional[Dict[str, Any]] = None

src/smartapp/signature.py

@@ -41,12 +41,13 @@
 from typing import List, Mapping, Optional
 
 import requests
+from arrow import Arrow
+from arrow import get as arrow_get
+from arrow import now as arrow_now
 from attrs import field, frozen
 from Cryptodome.Hash import SHA256
 from Cryptodome.PublicKey import RSA
 from Cryptodome.Signature import pkcs1_15
-from pendulum import from_format, now
-from pendulum.datetime import DateTime
 from requests import ConnectionError as RequestsConnectionError
 from requests import HTTPError, RequestException
 from tenacity import retry
@@ -72,7 +73,7 @@ def retrieve_public_key(key_server_url: str, key_id: str) -> str:
     return response.text
 
 
-DATE_FORMAT = "DD MMM YYYY HH:mm:ss z"  # like "05 Jan 2014 21:31:40 GMT"; we strip off the leading day of week
+DATE_FORMAT = "DD MMM YYYY HH:mm:ss ZZZ"  # like "05 Jan 2014 21:31:40 GMT"; we strip off the leading day of week
 
 
 # noinspection PyUnresolvedReferences
@@ -89,7 +90,7 @@ class SignatureVerifier:
     method: str = field(init=False)
     path: str = field(init=False)
     request_target: str = field(init=False)
-    date: DateTime = field(init=False)
+    date: Arrow = field(init=False)
     authorization: str = field(init=False)
     signing_attributes: Mapping[str, str] = field(init=False)
     signing_headers: str = field(init=False)
@@ -129,8 +130,8 @@ def _default_authorization(self) -> str:
         return self.header("authorization")
 
     @date.default
-    def _default_date(self) -> DateTime:
-        return from_format(self.header("date")[5:], DATE_FORMAT)  # remove the day ("Thu, ") from front
+    def _default_date(self) -> Arrow:
+        return arrow_get(self.header("date")[5:], DATE_FORMAT)  # remove the day ("Thu, ") from front
 
     @signing_attributes.default
     def _default_signing_attributes(self) -> Mapping[str, str]:
@@ -206,7 +207,7 @@ def retrieve_public_key(self) -> str:
     def verify_date(self) -> None:
         """Verify the date, ensuring that it is current per skew configuration."""
         if self.config.clock_skew_sec is not None:
-            skew = abs(now() - self.date)
+            skew = abs(arrow_now() - self.date)
             if skew.seconds > self.config.clock_skew_sec:
                 raise SignatureError("Request date is not current, skew of %d seconds" % skew.seconds, self.correlation_id)
 

tests/test_converter.py

@@ -6,8 +6,8 @@
 from json import JSONDecodeError
 from unittest.mock import patch
 
-import pendulum
 import pytest
+from arrow import arrow
 
 from smartapp.converter import CONVERTER, deserialize_datetime, serialize_datetime
 from smartapp.interface import *
@@ -18,7 +18,7 @@
 RESPONSE_DIR = os.path.join(FIXTURE_DIR, "response")
 SETTINGS_DIR = os.path.join(FIXTURE_DIR, "settings")
 
-NOW = pendulum.datetime(2022, 6, 1, 2, 3, 4, microsecond=5, tz="UTC")
+NOW = arrow.Arrow(2022, 6, 1, 2, 3, 4, microsecond=5, tzinfo="UTC")
 
 
 @pytest.fixture
@@ -58,24 +58,25 @@ class TestDatetime:
     @pytest.mark.parametrize(
         "datetime,expected",
         [
-            (pendulum.datetime(2017, 9, 13, 4, 18, 12, microsecond=469000, tz="UTC"), "2017-09-13T04:18:12.469Z"),
-            (pendulum.datetime(2017, 9, 13, 4, 18, 12, microsecond=0, tz="UTC"), "2017-09-13T04:18:12.000Z"),
-            (pendulum.datetime(1970, 1, 1, 0, 0, 0, microsecond=0, tz="UTC"), "1970-01-01T00:00:00.000Z"),
+            (arrow.Arrow(2017, 9, 13, 4, 18, 12, microsecond=469000, tzinfo="UTC"), "2017-09-13T04:18:12.469Z"),
+            (arrow.Arrow(2017, 9, 13, 4, 18, 12, microsecond=469123, tzinfo="UTC"), "2017-09-13T04:18:12.469Z"),
+            (arrow.Arrow(2017, 9, 13, 4, 18, 12, microsecond=0, tzinfo="UTC"), "2017-09-13T04:18:12.000Z"),
+            (arrow.Arrow(1970, 1, 1, 0, 0, 0, microsecond=0, tzinfo="UTC"), "1970-01-01T00:00:00.000Z"),
         ],
     )
     def test_serialize_datetime(self, datetime, expected):
         assert serialize_datetime(datetime) == expected
 
-    @patch("smartapp.converter.now")
+    @patch("smartapp.converter.arrow_now")
     @pytest.mark.parametrize(
         "datetime,expected",
         [
-            ("2017-09-13T04:18:12.469Z", pendulum.datetime(2017, 9, 13, 4, 18, 12, microsecond=469000, tz="UTC")),
-            ("2017-09-13T04:18:12.000Z", pendulum.datetime(2017, 9, 13, 4, 18, 12, microsecond=0, tz="UTC")),
-            ("2017-09-13T04:18:12Z", pendulum.datetime(2017, 9, 13, 4, 18, 12, microsecond=0, tz="UTC")),
-            ("2022-06-16T15:17:24.883Z", pendulum.datetime(2022, 6, 16, 10, 17, 24, microsecond=883000, tz="America/Chicago")),
-            ("2022-06-16T15:17:24.000Z", pendulum.datetime(2022, 6, 16, 10, 17, 24, microsecond=0, tz="America/Chicago")),
-            ("2022-06-16T15:16:24Z", pendulum.datetime(2022, 6, 16, 10, 16, 24, microsecond=0, tz="America/Chicago")),
+            ("2017-09-13T04:18:12.469Z", arrow.Arrow(2017, 9, 13, 4, 18, 12, microsecond=469000, tzinfo="UTC")),
+            ("2017-09-13T04:18:12.000Z", arrow.Arrow(2017, 9, 13, 4, 18, 12, microsecond=0, tzinfo="UTC")),
+            ("2017-09-13T04:18:12Z", arrow.Arrow(2017, 9, 13, 4, 18, 12, microsecond=0, tzinfo="UTC")),
+            ("2022-06-16T15:17:24.883Z", arrow.Arrow(2022, 6, 16, 10, 17, 24, microsecond=883000, tzinfo="America/Chicago")),
+            ("2022-06-16T15:17:24.000Z", arrow.Arrow(2022, 6, 16, 10, 17, 24, microsecond=0, tzinfo="America/Chicago")),
+            ("2022-06-16T15:16:24Z", arrow.Arrow(2022, 6, 16, 10, 16, 24, microsecond=0, tzinfo="America/Chicago")),
             ("1970-01-01T00:00:00.000Z", NOW),
             ("1970-01-01T00:00:00Z", NOW),
         ],