fix: deprecate with warning pytz instead of deleting

Author: JoLo90

ci/requirements-py3.10-min.yml

@@ -9,6 +9,7 @@ dependencies:
     - pytest-mock
     - pytest-timeout
     - python=3.10
+    - pytz
     - requests
     - pip:
         - h5py==3.6.0

ci/requirements-py3.10.yml

@@ -19,10 +19,10 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.10
+    - pytz
     - requests
     - scipy >= 1.7.2
     - statsmodels
     - pip:
         - nrel-pysam>=2.0
         - solarfactors
-        - tzdata; platform_system == "Windows"

ci/requirements-py3.11.yml

@@ -19,10 +19,10 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.11
+    - pytz
     - requests
     - scipy >= 1.7.2
     - statsmodels
     - pip:
         - nrel-pysam>=2.0
         - solarfactors
-        - tzdata; platform_system == "Windows"

ci/requirements-py3.12.yml

@@ -19,10 +19,10 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.12
+    - pytz
     - requests
     - scipy >= 1.7.2
     - statsmodels
     - pip:
         - nrel-pysam>=2.0
         - solarfactors
-        - tzdata; platform_system == "Windows"

ci/requirements-py3.13.yml

@@ -19,10 +19,10 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.13
+    - pytz
     - requests
     - scipy >= 1.7.2
     - statsmodels
     - pip:
         - nrel-pysam>=2.0
         - solarfactors
-        - tzdata; platform_system == "Windows"

ci/requirements-py3.14.yml

@@ -19,10 +19,10 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.14
+    - pytz
     - requests
     - scipy >= 1.7.2
     - statsmodels
     - pip:
         # - nrel-pysam>=2.0  # not available for py 3.14 as of 2025-11-03
         - solarfactors
-        - tzdata; platform_system == "Windows"

docs/sphinx/source/whatsnew/v0.15.2.rst

@@ -45,9 +45,6 @@ Benchmarking
 
 Requirements
 ~~~~~~~~~~~~
-* Removed ``pytz`` from core dependencies. ``zoneinfo`` (built into Python 3.9+)
-  is now used instead. On Windows, the ``tzdata`` package is required and
-  installed automatically. (:ghuser:`JoLo90`, :pull:`2757`)
 
 
 Maintenance

pvlib/location.py

@@ -9,10 +9,12 @@
 import zoneinfo
 
 import pandas as pd
+import pytz
 import h5py
 
 from pvlib import solarposition, clearsky, atmosphere, irradiance
 from pvlib.tools import _degrees_to_index
+from pvlib._deprecation import warn_deprecated
 
 
 class Location:
@@ -25,7 +27,7 @@ class Location:
 
         * ``tz`` is an IANA time-zone string.
 
-       The ``pytz`` attribute was removed. Use ``tz`` property instead.
+       The ``pytz`` attribute is deprecated. Use ``tz`` property instead.
 
     Location objects support the print method.
 
@@ -126,6 +128,23 @@ def tz(self, tz_):
                 "datetime.tzinfo object (including subclasses)"
             )
 
+    @property
+    def pytz(self):  # pragma: no cover
+        """The location's pytz time zone (read only).
+
+        .. deprecated::
+            The ``pytz`` attribute is deprecated. Use the ``tz`` property
+            instead.
+        """
+        warn_deprecated(
+            since='0.15.2',
+            removal='0.17.0',
+            name='pytz',
+            obj_type='attribute',
+            alternative='tz',
+        )
+        return pytz.timezone(str(self._zoneinfo))
+
     @classmethod
     def from_tmy(cls, tmy_metadata, tmy_data=None, **kwargs):
         """

pyproject.toml

@@ -13,10 +13,10 @@ requires-python = ">=3.10"
 dependencies = [
     'numpy >= 1.21.2',
     'pandas >= 1.3.3',
+    'pytz',
     'requests',
     'scipy >= 1.7.2',
     'h5py',
-    'tzdata; sys_platform == "win32"',
 ]
 license = "BSD-3-Clause"
 classifiers = [