use zoneinfo instead of pytz where possible (#93)

dirty_equals/_datetime.py

@@ -1,9 +1,14 @@
+from __future__ import annotations as _annotations
+
 from datetime import date, datetime, timedelta, timezone, tzinfo
-from typing import Any, Optional, Union
+from typing import TYPE_CHECKING, Any
 
 from ._numeric import IsNumeric
 from ._utils import Omit
 
+if TYPE_CHECKING:
+    from zoneinfo import ZoneInfo
+
 
 class IsDatetime(IsNumeric[datetime]):
     """
@@ -15,15 +20,15 @@ class IsDatetime(IsNumeric[datetime]):
     def __init__(
         self,
         *,
-        approx: Optional[datetime] = None,
-        delta: Optional[Union[timedelta, int, float]] = None,
-        gt: Optional[datetime] = None,
-        lt: Optional[datetime] = None,
-        ge: Optional[datetime] = None,
-        le: Optional[datetime] = None,
+        approx: datetime | None = None,
+        delta: timedelta | int | float | None = None,
+        gt: datetime | None = None,
+        lt: datetime | None = None,
+        ge: datetime | None = None,
+        le: datetime | None = None,
         unix_number: bool = False,
         iso_string: bool = False,
-        format_string: Optional[str] = None,
+        format_string: str | None = None,
         enforce_tz: bool = True,
     ):
         """
@@ -117,6 +122,24 @@ def approx_equals(self, other: datetime, delta: timedelta) -> bool:
             return True
 
 
+def _zoneinfo(tz: str) -> ZoneInfo:
+    """
+    Instantiate a `ZoneInfo` object from a string, falling back to `pytz.timezone` when `ZoneInfo` is not available
+    (most likely on Python 3.8 and webassembly).
+    """
+    try:
+        from zoneinfo import ZoneInfo
+    except ImportError:
+        try:
+            import pytz
+        except ImportError as e:
+            raise ImportError('`pytz` or `zoneinfo` required for tz handling') from e
+        else:
+            return pytz.timezone(tz)  # type: ignore[return-value]
+    else:
+        return ZoneInfo(tz)
+
+
 class IsNow(IsDatetime):
     """
     Check if a datetime is close to now, this is similar to `IsDatetime(approx=datetime.now())`,
@@ -126,12 +149,12 @@ class IsNow(IsDatetime):
     def __init__(
         self,
         *,
-        delta: Union[timedelta, int, float] = 2,
+        delta: timedelta | int | float = 2,
         unix_number: bool = False,
         iso_string: bool = False,
-        format_string: Optional[str] = None,
+        format_string: str | None = None,
         enforce_tz: bool = True,
-        tz: Union[None, str, tzinfo] = None,
+        tz: str | tzinfo | None = None,
     ):
         """
         Args:
@@ -141,7 +164,8 @@ def __init__(
             iso_string: whether to allow iso formatted strings in comparison
             format_string: if provided, `format_string` is used with `datetime.strptime` to parse strings
             enforce_tz: whether timezone should be enforced in comparison, see below for more details
-            tz: either a `pytz.timezone`, a `datetime.timezone` or a string which will be passed to `pytz.timezone`,
+            tz: either a `ZoneInfo`, a `datetime.timezone` or a string which will be passed to `ZoneInfo`,
+                (or `pytz.timezone` on 3.8) to get a timezone,
                 if provided now will be converted to this timezone.
 
         ```py title="IsNow"
@@ -161,9 +185,7 @@ def __init__(
         ```
         """
         if isinstance(tz, str):
-            import pytz
-
-            tz = pytz.timezone(tz)
+            tz = _zoneinfo(tz)
 
         self.tz = tz
 
@@ -184,12 +206,7 @@ def _get_now(self) -> datetime:
         if self.tz is None:
             return datetime.now()
         else:
-            try:
-                from datetime import UTC
-
-                utc_now = datetime.now(UTC).replace(tzinfo=timezone.utc)
-            except ImportError:
-                utc_now = datetime.utcnow().replace(tzinfo=timezone.utc)
+            utc_now = datetime.now(tz=timezone.utc).replace(tzinfo=timezone.utc)
             return utc_now.astimezone(self.tz)
 
     def prepare(self, other: Any) -> datetime:
@@ -210,14 +227,14 @@ class IsDate(IsNumeric[date]):
     def __init__(
         self,
         *,
-        approx: Optional[date] = None,
-        delta: Optional[Union[timedelta, int, float]] = None,
-        gt: Optional[date] = None,
-        lt: Optional[date] = None,
-        ge: Optional[date] = None,
-        le: Optional[date] = None,
+        approx: date | None = None,
+        delta: timedelta | int | float | None = None,
+        gt: date | None = None,
+        lt: date | None = None,
+        ge: date | None = None,
+        le: date | None = None,
         iso_string: bool = False,
-        format_string: Optional[str] = None,
+        format_string: str | None = None,
     ):
         """
         Args:
@@ -286,7 +303,7 @@ def __init__(
         self,
         *,
         iso_string: bool = False,
-        format_string: Optional[str] = None,
+        format_string: str | None = None,
     ):
         """
         Args:

dirty_equals/_other.py

@@ -157,7 +157,7 @@ def equals(self, other: Any) -> bool:
 T = TypeVar('T')
 
 
-@lru_cache()
+@lru_cache
 def _build_type_adapter(ta: type[TypeAdapter[T]], schema: T) -> TypeAdapter[T]:
     return ta(schema)
 

docs/plugins.py

@@ -38,6 +38,7 @@ def remove_files(files: Files) -> Files:
 
 
 def on_page_markdown(markdown: str, page: Page, config: Config, files: Files) -> str:
+    markdown = remove_code_fence_attributes(markdown)
     return add_version(markdown, page)
 
 
@@ -56,3 +57,20 @@ def add_version(markdown: str, page: Page) -> str:
             version_str = 'Documentation for development version'
         markdown = re.sub(r'{{ *version *}}', version_str, markdown)
     return markdown
+
+
+def remove_code_fence_attributes(markdown: str) -> str:
+    """
+    There's no way to add attributes to code fences that works with both pycharm and mkdocs, hence we use
+    `py key="value"` to provide attributes to pytest-examples, then remove those attributes here.
+
+    https://youtrack.jetbrains.com/issue/IDEA-297873 & https://python-markdown.github.io/extensions/fenced_code_blocks/
+    """
+
+    def remove_attrs(match: re.Match[str]) -> str:
+        suffix = re.sub(
+            r' (?:test|lint|upgrade|group|requires|output|rewrite_assert)=".+?"', '', match.group(2), flags=re.M
+        )
+        return f'{match.group(1)}{suffix}'
+
+    return re.sub(r'^( *``` *py)(.*)', remove_attrs, markdown, flags=re.M)

docs/types/datetime.md

@@ -21,18 +21,17 @@ based on the `enforce_tz` parameter:
 
 Example
 
-```py title="IsDatetime & timezones"
+```py title="IsDatetime & timezones" requires="3.9"
 from datetime import datetime
-
-import pytz
+from zoneinfo import ZoneInfo
 
 from dirty_equals import IsDatetime
 
-tz_london = pytz.timezone('Europe/London')
-new_year_london = tz_london.localize(datetime(2000, 1, 1))
+tz_london = ZoneInfo('Europe/London')
+new_year_london = datetime(2000, 1, 1, tzinfo=tz_london)
 
-tz_nyc = pytz.timezone('America/New_York')
-new_year_eve_nyc = tz_nyc.localize(datetime(1999, 12, 31, 19, 0, 0))
+tz_nyc = ZoneInfo('America/New_York')
+new_year_eve_nyc = datetime(1999, 12, 31, 19, 0, 0, tzinfo=tz_nyc)
 
 assert new_year_eve_nyc == IsDatetime(approx=new_year_london, enforce_tz=False)
 assert new_year_eve_nyc != IsDatetime(approx=new_year_london, enforce_tz=True)

pyproject.toml

@@ -36,7 +36,7 @@ classifiers = [
 ]
 requires-python = '>=3.8'
 dependencies = [
-    'pytz>=2021.3',
+    'pytz>=2021.3;python_version<"3.9"',
 ]
 optional-dependencies = {pydantic = ['pydantic>=2.4.2'] }
 dynamic = ['version']
@@ -55,7 +55,10 @@ flake8-quotes = {inline-quotes = 'single', multiline-quotes = 'double'}
 mccabe = { max-complexity = 14 }
 isort = { known-first-party = ['tests'] }
 format.quote-style = 'single'
-target-version = 'py37'
+target-version = 'py38'
+
+[tool.ruff.pydocstyle]
+convention = 'google'
 
 [tool.pytest.ini_options]
 testpaths = "tests"

requirements/pyproject.txt

@@ -16,8 +16,6 @@ pydantic-core==2.10.1
     # via
     #   -c requirements/linting.txt
     #   pydantic
-pytz==2023.3.post1
-    # via dirty-equals (pyproject.toml)
 typing-extensions==4.8.0
     # via
     #   -c requirements/linting.txt

requirements/tests.in

@@ -4,3 +4,4 @@ pytest
 pytest-mock
 pytest-pretty
 pytest-examples
+pytz

requirements/tests.txt

@@ -45,6 +45,8 @@ pytest-mock==3.12.0
     # via -r requirements/tests.in
 pytest-pretty==1.2.0
     # via -r requirements/tests.in
+pytz==2023.3.post1
+    # via -r requirements/tests.in
 rich==13.6.0
     # via pytest-pretty
 ruff==0.1.5

tests/test_datetime.py

@@ -6,6 +6,11 @@
 
 from dirty_equals import IsDate, IsDatetime, IsNow, IsToday
 
+try:
+    from zoneinfo import ZoneInfo
+except ImportError:
+    ZoneInfo = None
+
 
 @pytest.mark.parametrize(
     'value,dirty,expect_match',
@@ -82,6 +87,14 @@ def test_is_datetime(value, dirty, expect_match):
         assert value != dirty
 
 
+@pytest.mark.skipif(ZoneInfo is None, reason='requires zoneinfo')
+def test_is_datetime_zoneinfo():
+    london = datetime(2022, 2, 15, 15, 15, tzinfo=ZoneInfo('Europe/London'))
+    ny = datetime(2022, 2, 15, 10, 15, tzinfo=ZoneInfo('America/New_York'))
+    assert london != IsDatetime(approx=ny)
+    assert london == IsDatetime(approx=ny, enforce_tz=False)
+
+
 def test_is_now_dt():
     is_now = IsNow()
     dt = datetime.now()
@@ -98,14 +111,10 @@ def test_repr():
     assert str(v) == 'IsDatetime(approx=datetime.datetime(2032, 1, 2, 3, 4, 5), iso_string=True)'
 
 
+@pytest.mark.skipif(ZoneInfo is None, reason='requires zoneinfo')
 def test_is_now_tz():
-    try:
-        from datetime import UTC
-
-        utc_now = datetime.now(UTC).replace(tzinfo=timezone.utc)
-    except ImportError:
-        utc_now = datetime.utcnow().replace(tzinfo=timezone.utc)
-    now_ny = utc_now.astimezone(pytz.timezone('America/New_York'))
+    utc_now = datetime.now(timezone.utc).replace(tzinfo=timezone.utc)
+    now_ny = utc_now.astimezone(ZoneInfo('America/New_York'))
     assert now_ny == IsNow(tz='America/New_York')
     # depends on the time of year and DST
     assert now_ny == IsNow(tz=timezone(timedelta(hours=-5))) | IsNow(tz=timezone(timedelta(hours=-4)))
@@ -132,10 +141,11 @@ def test_is_now_relative(monkeypatch):
     assert IsNow() == datetime(2020, 1, 1, 12, 13, 14)
 
 
+@pytest.mark.skipif(ZoneInfo is None, reason='requires zoneinfo')
 def test_tz():
-    new_year_london = pytz.timezone('Europe/London').localize(datetime(2000, 1, 1))
+    new_year_london = datetime(2000, 1, 1, tzinfo=ZoneInfo('Europe/London'))
 
-    new_year_eve_nyc = pytz.timezone('America/New_York').localize(datetime(1999, 12, 31, 19, 0, 0))
+    new_year_eve_nyc = datetime(1999, 12, 31, 19, 0, 0, tzinfo=ZoneInfo('America/New_York'))
 
     assert new_year_eve_nyc == IsDatetime(approx=new_year_london, enforce_tz=False)
     assert new_year_eve_nyc != IsDatetime(approx=new_year_london, enforce_tz=True)

tests/test_docs.py

@@ -22,6 +22,12 @@ def test_docstrings(example: CodeExample, eval_example: EvalExample):
     # I001 refers is a problem with black and ruff disagreeing about blank lines :shrug:
     eval_example.set_config(ruff_ignore=['E711', 'E712', 'I001'])
 
+    requires = prefix_settings.get('requires')
+    if requires:
+        requires_version = tuple(int(v) for v in requires.split('.'))
+        if sys.version_info < requires_version:
+            pytest.skip(f'requires python {requires}')
+
     if prefix_settings.get('test') != 'skip':
         if eval_example.update_examples:
             eval_example.run_print_update(example)