Update mypy and fix issues (#680)

* Update mypy and fix issues

* Fix install invocation

* Remove importing _winreg

* Remove namedtuple usage

* Update to mypy 1.0.1

* Fix mypy errors

* Only build the project once in CI

* Improve more typing

* Update mypy and fix errors

* Move `timezone()` to main module to work around mypy sometimes mixing up the function and module

* Improve `ClassVar` setting for `DateTime`

* Fix unused ignore error

Author: bryanforbes

.flake8

@@ -4,8 +4,9 @@ per-file-ignores =
     # F401:	Module imported but unused
     # TC001: Move import into type checking block
     __init__.py:F401, TC001
+    pendulum/date.py:E800
     # F811:	Redefinition of unused name from line n
-    pendulum/tz/timezone.py:F811
+    pendulum/tz/timezone.py:F811, E800
 min_python_version = 3.7.0
 ban-relative-imports = true
 # flake8-use-fstring: https://github.com/MichaelKim0407/flake8-use-fstring#--percent-greedy-and---format-greedy

.github/workflows/tests.yml

@@ -64,8 +64,15 @@ jobs:
         if: steps.cache.outputs.cache-hit == 'true' && matrix.os != 'MacOS'
         run: timeout 10s poetry run pip --version || rm -rf .venv
 
-      - name: Install dependencies
-        run: poetry install --only main --only test -vvv
+      - name: Install runtime, testing, and typing dependencies
+        run: poetry install --only main --only test --only typing -vvv
+
+      - name: Run type checking
+        run: poetry run mypy
+
+      - name: Uninstall typing dependencies
+        # This ensures pendulum runs without typing_extensions installed
+        run: poetry install --only main --only test --sync --no-root -vvv
 
       - name: Test Pure Python
         run: |

.pre-commit-config.yaml

@@ -58,14 +58,3 @@ repos:
         exclude: ^build\.py$
         args:
           - --py37-plus
-
-  - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.982
-    hooks:
-      - id: mypy
-        pass_filenames: false
-        exclude: ^build\.py$
-        additional_dependencies:
-          - pytest>=7.1.2
-          - types-backports
-          - types-python-dateutil

pendulum/__init__.py

@@ -4,6 +4,7 @@
 
 from typing import Union
 from typing import cast
+from typing import overload
 
 from pendulum.__version__ import __version__
 from pendulum.constants import DAYS_PER_WEEK
@@ -38,10 +39,10 @@
 from pendulum.testing.traveller import Traveller
 from pendulum.time import Time
 from pendulum.tz import UTC
+from pendulum.tz import fixed_timezone
 from pendulum.tz import local_timezone
 from pendulum.tz import set_local_timezone
 from pendulum.tz import test_local_timezone
-from pendulum.tz import timezone
 from pendulum.tz import timezones
 from pendulum.tz.timezone import FixedTimezone
 from pendulum.tz.timezone import Timezone
@@ -54,6 +55,34 @@
 _formatter = Formatter()
 
 
+@overload
+def timezone(name: int) -> FixedTimezone:
+    ...
+
+
+@overload
+def timezone(name: str) -> Timezone:
+    ...
+
+
+@overload
+def timezone(name: str | int) -> Timezone | FixedTimezone:
+    ...
+
+
+def timezone(name: str | int) -> Timezone | FixedTimezone:
+    """
+    Return a Timezone instance given its name.
+    """
+    if isinstance(name, int):
+        return fixed_timezone(name)
+
+    if name.lower() == "utc":
+        return UTC
+
+    return Timezone(name)
+
+
 def _safe_timezone(
     obj: str | float | _datetime.tzinfo | Timezone | FixedTimezone | None,
     dt: _datetime.datetime | None = None,
@@ -73,7 +102,7 @@ def _safe_timezone(
     elif isinstance(obj, _datetime.tzinfo):
         # zoneinfo
         if hasattr(obj, "key"):
-            obj = obj.key  # type: ignore
+            obj = obj.key
         # pytz
         elif hasattr(obj, "localize"):
             obj = obj.zone  # type: ignore

pendulum/_extensions/_helpers.pyi

@@ -1,8 +1,8 @@
 from __future__ import annotations
 
-from collections import namedtuple
 from datetime import date
 from datetime import datetime
+from typing import NamedTuple
 
 def days_in_year(year: int) -> int: ...
 def is_leap(year: int) -> bool: ...
@@ -11,12 +11,7 @@ def local_time(
     unix_time: int, utc_offset: int, microseconds: int
 ) -> tuple[int, int, int, int, int, int, int]: ...
 
-class PreciseDiff(
-    namedtuple(
-        "PreciseDiff",
-        "years months days " "hours minutes seconds microseconds " "total_days",
-    )
-):
+class PreciseDiff(NamedTuple):
     years: int
     months: int
     days: int

pendulum/_extensions/helpers.py

@@ -3,7 +3,7 @@
 import datetime
 import math
 
-from collections import namedtuple
+from typing import NamedTuple
 from typing import cast
 
 from pendulum.constants import DAY_OF_WEEK_TABLE
@@ -25,12 +25,7 @@
 from pendulum.utils._compat import zoneinfo
 
 
-class PreciseDiff(
-    namedtuple(
-        "PreciseDiff",
-        "years months days " "hours minutes seconds microseconds " "total_days",
-    )
-):
+class PreciseDiff(NamedTuple):
     years: int
     months: int
     days: int