Fix #807: handle pytz.FixedOffset in pendulum.instance()

pendulum.instance() raised 'AttributeError: NoneType object has no
attribute lower' for datetimes whose tzinfo is a pytz.FixedOffset.

_safe_timezone() detects pytz zones via their localize() method and then
uses their .zone name. Named pytz zones carry a zone string, but fixed-offset
zones (pytz.FixedOffset) have zone = None, so that None was passed to
timezone(), which crashed. Fall back to the tzinfo's UTC offset when there is
no zone name, mirroring how other offset-only tzinfos are handled.

Added a regression test (skipped when pytz is unavailable).

Author: apoorvdarshan

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Change Log
 
+## [Unreleased]
+
+### Changed
+- Fixed `pendulum.instance()` raising `AttributeError` for datetimes with a `pytz.FixedOffset` timezone [#981](https://github.com/python-pendulum/pendulum/pull/981)
+
 ## [3.2.0] - 2026-01-30
 
 ### Added

src/pendulum/__init__.py

@@ -105,7 +105,17 @@ def _safe_timezone(
             obj = obj.key
         # pytz
         elif hasattr(obj, "localize"):
-            obj = obj.zone  # type: ignore[attr-defined]
+            # Named pytz zones expose a ``zone`` name, but fixed-offset zones
+            # (``pytz.FixedOffset``) have ``zone = None``; use their offset.
+            if obj.zone is not None:  # type: ignore[attr-defined]
+                obj = obj.zone  # type: ignore[attr-defined]
+            else:
+                offset = obj.utcoffset(dt)
+
+                if offset is None:
+                    offset = _datetime.timedelta(0)
+
+                obj = int(offset.total_seconds())
         elif obj.tzname(None) == "UTC":
             return UTC
         else:

tests/test_main.py

@@ -5,6 +5,9 @@
 from datetime import date
 from datetime import datetime
 from datetime import time
+from datetime import timedelta
+
+import pytest
 
 from dateutil import tz
 
@@ -36,6 +39,18 @@ def test_instance_with_aware_datetime_any_tzinfo() -> None:
     assert now.timezone_name == "+02:00"
 
 
+def test_instance_with_pytz_fixed_offset() -> None:
+    # ``pytz.FixedOffset`` has a ``localize`` method but no ``zone`` name,
+    # which used to raise ``AttributeError`` in ``_safe_timezone`` (#807).
+    pytz = pytest.importorskip("pytz")
+
+    dt = pendulum.instance(datetime(2021, 2, 3, tzinfo=pytz.FixedOffset(60)))
+    assert dt.utcoffset() == timedelta(minutes=60)
+
+    dt = pendulum.instance(datetime(2021, 2, 3, tzinfo=pytz.FixedOffset(-330)))
+    assert dt.utcoffset() == timedelta(minutes=-330)
+
+
 def test_instance_with_date() -> None:
     dt = pendulum.instance(date(2022, 12, 23))