Replace pytz with standard library's zoneinfo

ci/requirements-py3.10.yml

@@ -19,7 +19,7 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.10
-    - pytz
+    # - pytz
     - requests
     - scipy >= 1.6.0
     - statsmodels

ci/requirements-py3.11.yml

@@ -19,7 +19,7 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.11
-    - pytz
+    # - pytz
     - requests
     - scipy >= 1.6.0
     - statsmodels

ci/requirements-py3.12.yml

@@ -19,7 +19,7 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.12
-    - pytz
+    # - pytz
     - requests
     - scipy >= 1.6.0
     - statsmodels

ci/requirements-py3.9-min.yml

@@ -9,7 +9,7 @@ dependencies:
     - pytest-mock
     - pytest-timeout
     - python=3.9
-    - pytz
+    # - pytz
     - requests
     - pip:
         - h5py==3.0.0

ci/requirements-py3.9.yml

@@ -19,7 +19,7 @@ dependencies:
     - pytest-rerunfailures
     - conda-forge::pytest-remotedata  # version in default channel is old
     - python=3.9
-    - pytz
+    # - pytz
     - requests
     - scipy >= 1.6.0
     - statsmodels

docs/sphinx/source/whatsnew/v0.11.3.rst

@@ -18,6 +18,7 @@ Documentation
 
 Testing
 ~~~~~~~
+* Add tests for time conversions in tools package. (:issue:`2340`, :pull:`2341`)
 
 
 Requirements
@@ -26,5 +27,4 @@ Requirements
 
 Contributors
 ~~~~~~~~~~~~
-
-
+* Mark Campanellli (:ghuser:`markcampanelli`)

pvlib/iotools/pvgis.py

@@ -17,10 +17,12 @@
 import io
 import json
 from pathlib import Path
+from zoneinfo import ZoneInfo
+
 import requests
 import numpy as np
 import pandas as pd
-import pytz
+
 from pvlib.iotools import read_epw, parse_epw
 
 URL = 'https://re.jrc.ec.europa.eu/api/'
@@ -398,10 +400,10 @@ def _coerce_and_roll_tmy(tmy_data, tz, year):
     re-interpreted as zero / UTC.
     """
     if tz:
-        tzname = pytz.timezone(f'Etc/GMT{-tz:+d}')
+        tzname = ZoneInfo(f'Etc/GMT{-tz:+d}')
     else:
         tz = 0
-        tzname = pytz.timezone('UTC')
+        tzname = ZoneInfo('UTC')
     new_index = pd.DatetimeIndex([
         timestamp.replace(year=year, tzinfo=tzname)
         for timestamp in tmy_data.index],

pvlib/location.py

@@ -4,14 +4,16 @@
 
 # Will Holmgren, University of Arizona, 2014-2016.
 
-import pathlib
 import datetime
+import pathlib
+from zoneinfo import ZoneInfo
 
-import pandas as pd
-import pytz
 import h5py
+import pandas as pd
+# import pytz
 
-from pvlib import solarposition, clearsky, atmosphere, irradiance
+from pvlib import atmosphere, clearsky, irradiance, solarposition
+# from pvlib._deprecation import warn_deprecated
 from pvlib.tools import _degrees_to_index
 
 
@@ -21,10 +23,12 @@ class Location:
     timezone, and altitude data associated with a particular
     geographic location. You can also assign a name to a location object.
 
-    Location objects have two timezone attributes:
+    Location objects have one timezone attribute:
+
+        * ``tz`` is a IANA-compatible standard-library zoneinfo.ZoneInfo.
 
-        * ``tz`` is a IANA timezone string.
-        * ``pytz`` is a pytz timezone object.
+    Thus, the passed timezone must be representable by one of the values in
+    zoneinfo.available_timezones().
 
     Location objects support the print method.
 
@@ -38,12 +42,13 @@ class Location:
         Positive is east of the prime meridian.
         Use decimal degrees notation.
 
-    tz : str, int, float, or pytz.timezone, default 'UTC'.
-        See
-        http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
-        for a list of valid time zones.
-        pytz.timezone objects will be converted to strings.
-        ints and floats must be in hours from UTC.
+    tz : str, int, float, zoneinfo.ZoneInfo, datetime.timezone, or pytz
+        timezone (deprecated), default 'UTC'.
+        See http://en.wikipedia.org/wiki/List_of_tz_database_time_zones for a
+        list of valid time zone strings, or use the function
+        zoneinfo.available_timezones().
+        ints and floats must be in hours N from UTC, and are converted to the
+        Etc/GMT+N or Etc/GMT-N format depending on the sign of N.
 
     altitude : float, optional
         Altitude from sea level in meters.
@@ -59,33 +64,43 @@ class Location:
     pvlib.pvsystem.PVSystem
     """
 
-    def __init__(self, latitude, longitude, tz='UTC', altitude=None,
-                 name=None):
+    def __init__(
+        self, latitude, longitude, tz='UTC', altitude=None, name=None
+    ):
+
+        if name is None:
+            name = ""
+
+        self.name = name
 
         self.latitude = latitude
         self.longitude = longitude
 
-        if isinstance(tz, str):
-            self.tz = tz
-            self.pytz = pytz.timezone(tz)
-        elif isinstance(tz, datetime.timezone):
-            self.tz = 'UTC'
-            self.pytz = pytz.UTC
-        elif isinstance(tz, datetime.tzinfo):
-            self.tz = tz.zone
-            self.pytz = tz
-        elif isinstance(tz, (int, float)):
-            self.tz = tz
-            self.pytz = pytz.FixedOffset(tz*60)
-        else:
-            raise TypeError('Invalid tz specification')
-
         if altitude is None:
             altitude = lookup_altitude(latitude, longitude)
 
         self.altitude = altitude
 
-        self.name = name
+        if isinstance(tz, str):
+            self.tz = ZoneInfo(tz)
+        elif isinstance(tz, int):
+            self.tz = ZoneInfo(f"Etc/GMT{-tz:+d}")
+        elif isinstance(tz, float):
+            self.tz = ZoneInfo(f"Etc/GMT{int(-tz):+d}")
+        elif isinstance(tz, ZoneInfo):
+            self.tz = tz
+        elif isinstance(tz, datetime.timezone):
+            self.tz = ZoneInfo(str(tz))
+        # elif isinstance(tz, pytz.BaseTzInfo):
+        #     warn_deprecated(
+        #         "0.11.3",
+        #         message='pytz-based timezones are deprecated for locations',
+        #         alternative='use zoneinfo.ZoneInfo from standard library',
+        #         obj_type='function argument type',
+        #     )
+        #     self.tz = ZoneInfo(tz.zone)
+        else:
+            raise TypeError(f'Invalid tz specification: {tz}')
 
     def __repr__(self):
         attrs = ['name', 'latitude', 'longitude', 'altitude', 'tz']

pvlib/temperature.py

@@ -6,7 +6,6 @@
 import numpy as np
 import pandas as pd
 from pvlib.tools import sind
-from pvlib._deprecation import warn_deprecated
 from pvlib.tools import _get_sample_intervals
 import scipy
 import scipy.constants

pvlib/tests/iotools/test_midc.py

@@ -1,6 +1,5 @@
 import pandas as pd
 import pytest
-import pytz
 
 from pvlib.iotools import midc
 from ..conftest import DATA_DIR, RERUNS, RERUNS_DELAY
@@ -43,7 +42,7 @@ def test_midc__format_index_tz_conversion():
     data = pd.read_csv(MIDC_TESTFILE)
     data = data.rename(columns={'MST': 'PST'})
     data = midc._format_index(data)
-    assert data.index[0].tz == pytz.timezone('Etc/GMT+8')
+    assert str(data.index[0].tz) == 'Etc/GMT+8'
 
 
 def test_midc__format_index_raw():

pvlib/tests/test_clearsky.py

@@ -1,9 +1,9 @@
 from collections import OrderedDict
+from zoneinfo import ZoneInfo
 
 import numpy as np
 from numpy import nan
 import pandas as pd
-import pytz
 from scipy.linalg import hankel
 
 import pytest
@@ -758,7 +758,7 @@ def test_bird():
     times = pd.date_range(start='1/1/2015 0:00', end='12/31/2015 23:00',
                           freq='h')
     tz = -7  # test timezone
-    gmt_tz = pytz.timezone('Etc/GMT%+d' % -(tz))
+    gmt_tz = ZoneInfo(f"Etc/GMT{-tz:+}")
     times = times.tz_localize(gmt_tz)  # set timezone
     times_utc = times.tz_convert('UTC')
     # match test data from BIRD_08_16_2012.xls

pvlib/tests/test_location.py

@@ -1,15 +1,14 @@
 import datetime
 from unittest.mock import ANY
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
 
 import numpy as np
 from numpy import nan
 import pandas as pd
 from .conftest import assert_frame_equal, assert_index_equal
 
 import pytest
-
-import pytz
-from pytz.exceptions import UnknownTimeZoneError
+# import pytz
 
 import pvlib
 from pvlib import location
@@ -27,16 +26,23 @@ def test_location_all():
     Location(32.2, -111, 'US/Arizona', 700, 'Tucson')
 
 
-@pytest.mark.parametrize('tz', [
-    pytz.timezone('US/Arizona'), 'America/Phoenix',  -7, -7.0,
-    datetime.timezone.utc
-])
+@pytest.mark.parametrize(
+    'tz',
+    [
+        # pytz.timezone('US/Arizona'),
+        ZoneInfo('US/Arizona'),
+        'America/Phoenix',
+        -7,
+        -7.0,
+        datetime.timezone.utc,
+    ]
+)
 def test_location_tz(tz):
     Location(32.2, -111, tz)
 
 
 def test_location_invalid_tz():
-    with pytest.raises(UnknownTimeZoneError):
+    with pytest.raises(ZoneInfoNotFoundError):
         Location(32.2, -111, 'invalid')
 
 
@@ -58,8 +64,8 @@ def test_location_print_all():
     assert tus.__str__() == expected_str
 
 
-def test_location_print_pytz():
-    tus = Location(32.2, -111, pytz.timezone('US/Arizona'), 700, 'Tucson')
+def test_location_print_zoneinfo():
+    tus = Location(32.2, -111, ZoneInfo('US/Arizona'), 700, 'Tucson')
     expected_str = '\n'.join([
         'Location: ',
         '  name: Tucson',
@@ -215,7 +221,7 @@ def test_from_tmy_3():
     from pvlib.iotools import read_tmy3
     data, meta = read_tmy3(TMY3_TESTFILE, map_variables=True)
     loc = Location.from_tmy(meta, data)
-    assert loc.name is not None
+    assert loc.name != ""
     assert loc.altitude != 0
     assert loc.tz != 'UTC'
     assert_frame_equal(loc.weather, data)
@@ -226,7 +232,7 @@ def test_from_tmy_2():
     from pvlib.iotools import read_tmy2
     data, meta = read_tmy2(TMY2_TESTFILE)
     loc = Location.from_tmy(meta, data)
-    assert loc.name is not None
+    assert loc.name != ""
     assert loc.altitude != 0
     assert loc.tz != 'UTC'
     assert_frame_equal(loc.weather, data)
@@ -237,7 +243,7 @@ def test_from_epw():
     from pvlib.iotools import read_epw
     data, meta = read_epw(epw_testfile)
     loc = Location.from_epw(meta, data)
-    assert loc.name is not None
+    assert loc.name != ""
     assert loc.altitude != 0
     assert loc.tz != 'UTC'
     assert_frame_equal(loc.weather, data)