Remove compat for Python lower than 3.9

.circleci/config.yml

@@ -92,4 +92,4 @@ workflows:
               only: /^v.*/
           matrix:
             parameters:
-              cibw-build: ["cp38-manylinux_aarch64", "cp39-manylinux_aarch64", "cp310-manylinux_aarch64", "cp311-manylinux_aarch64"]
+              cibw-build: ["cp39-manylinux_aarch64", "cp310-manylinux_aarch64", "cp311-manylinux_aarch64"]

pandas/compat/__init__.py

@@ -16,7 +16,6 @@
 
 from pandas.compat._constants import (
     IS64,
-    PY39,
     PY310,
     PY311,
     PYPY,
@@ -161,7 +160,6 @@ def get_lzma_file() -> type[pandas.compat.compressors.LZMAFile]:
     "pa_version_under9p0",
     "pa_version_under11p0",
     "IS64",
-    "PY39",
     "PY310",
     "PY311",
     "PYPY",

pandas/compat/_constants.py

@@ -12,15 +12,13 @@
 
 IS64 = sys.maxsize > 2**32
 
-PY39 = sys.version_info >= (3, 9)
 PY310 = sys.version_info >= (3, 10)
 PY311 = sys.version_info >= (3, 11)
 PYPY = platform.python_implementation() == "PyPy"
 
 
 __all__ = [
     "IS64",
-    "PY39",
     "PY310",
     "PY311",
     "PYPY",

pandas/conftest.py

@@ -64,7 +64,6 @@
     Series,
     Timedelta,
     Timestamp,
-    compat,
 )
 import pandas._testing as tm
 from pandas.core import ops
@@ -81,18 +80,12 @@
     del pa
     has_pyarrow = True
 
-zoneinfo = None
-if compat.PY39:
-    # Import "zoneinfo" could not be resolved (reportMissingImports)
-    import zoneinfo  # type: ignore[assignment]
+import zoneinfo
 
-    # Although zoneinfo can be imported in Py39, it is effectively
-    # "not available" without tzdata/IANA tz data.
-    # We will set zoneinfo to not found in this case
-    try:
-        zoneinfo.ZoneInfo("UTC")  # type: ignore[attr-defined]
-    except zoneinfo.ZoneInfoNotFoundError:  # type: ignore[attr-defined]
-        zoneinfo = None
+try:
+    zoneinfo.ZoneInfo("UTC")
+except zoneinfo.ZoneInfoNotFoundError:
+    zoneinfo = None  # type: ignore[assignment]
 
 
 # ----------------------------------------------------------------
@@ -1221,7 +1214,12 @@ def iris(datapath) -> DataFrame:
     timezone(timedelta(hours=-1), name="foo"),
 ]
 if zoneinfo is not None:
-    TIMEZONES.extend([zoneinfo.ZoneInfo("US/Pacific"), zoneinfo.ZoneInfo("UTC")])
+    TIMEZONES.extend(
+        [
+            zoneinfo.ZoneInfo("US/Pacific"),  # type: ignore[list-item]
+            zoneinfo.ZoneInfo("UTC"),  # type: ignore[list-item]
+        ]
+    )
 TIMEZONE_IDS = [repr(i) for i in TIMEZONES]
 
 
@@ -1964,9 +1962,7 @@ def using_copy_on_write() -> bool:
 
 warsaws = ["Europe/Warsaw", "dateutil/Europe/Warsaw"]
 if zoneinfo is not None:
-    warsaws.append(
-        zoneinfo.ZoneInfo("Europe/Warsaw")  # pyright: ignore[reportGeneralTypeIssues]
-    )
+    warsaws.append(zoneinfo.ZoneInfo("Europe/Warsaw"))  # type: ignore[arg-type]
 
 
 @pytest.fixture(params=warsaws)

pandas/core/computation/expr.py

@@ -17,7 +17,6 @@
 
 import numpy as np
 
-from pandas.compat import PY39
 from pandas.errors import UndefinedVariableError
 
 import pandas.core.common as com
@@ -208,9 +207,6 @@ def _filter_nodes(superclass, all_nodes=_all_nodes):
 _keyword_nodes = _filter_nodes(ast.keyword)
 _alias_nodes = _filter_nodes(ast.alias)
 
-if not PY39:
-    _slice_nodes = _filter_nodes(ast.slice)
-
 
 # nodes that we don't support directly but are needed for parsing
 _hacked_nodes = frozenset(["Assign", "Module", "Expr"])

pandas/tests/scalar/timestamp/test_constructors.py

@@ -5,6 +5,7 @@
     timedelta,
     timezone,
 )
+import zoneinfo
 
 import dateutil.tz
 from dateutil.tz import tzutc
@@ -13,10 +14,7 @@
 import pytz
 
 from pandas._libs.tslibs.dtypes import NpyDatetimeUnit
-from pandas.compat import (
-    PY39,
-    PY310,
-)
+from pandas.compat import PY310
 from pandas.errors import OutOfBoundsDatetime
 
 from pandas import (
@@ -25,9 +23,6 @@
     Timestamp,
 )
 
-if PY39:
-    import zoneinfo
-
 
 class TestTimestampConstructors:
     def test_construct_from_string_invalid_raises(self):
@@ -845,15 +840,13 @@ def test_timestamp_constructor_retain_fold(tz, fold):
     assert result == expected
 
 
-_tzs = ["dateutil/Europe/London"]
-if PY39:
-    try:
-        _tzs = [
-            "dateutil/Europe/London",
-            zoneinfo.ZoneInfo("Europe/London"),  # type: ignore[list-item]
-        ]
-    except zoneinfo.ZoneInfoNotFoundError:
-        pass
+try:
+    _tzs = [
+        "dateutil/Europe/London",
+        zoneinfo.ZoneInfo("Europe/London"),
+    ]
+except zoneinfo.ZoneInfoNotFoundError:
+    _tzs = ["dateutil/Europe/London"]
 
 
 @pytest.mark.parametrize("tz", _tzs)