DEPS: Drop Python 3.9

.github/workflows/package-checks.yml

@@ -53,7 +53,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11']
+        python-version: ['3.10', '3.11']
       fail-fast: false
     name: Test Conda Forge Recipe - Python ${{ matrix.python-version }}
     concurrency:

.github/workflows/unit-tests.yml

@@ -26,7 +26,7 @@ jobs:
     timeout-minutes: 90
     strategy:
       matrix:
-        env_file: [actions-39.yaml, actions-310.yaml, actions-311.yaml, actions-312.yaml]
+        env_file: [actions-310.yaml, actions-311.yaml, actions-312.yaml]
         # Prevent the include jobs from overriding other jobs
         pattern: [""]
         include:
@@ -35,7 +35,7 @@ jobs:
             pattern: "not slow and not network and not single_cpu"
             pytest_target: "pandas/tests/test_downstream.py"
           - name: "Minimum Versions"
-            env_file: actions-39-minimum_versions.yaml
+            env_file: actions-310-minimum_versions.yaml
             pattern: "not slow and not network and not single_cpu"
           - name: "Locale: it_IT"
             env_file: actions-311.yaml
@@ -58,7 +58,7 @@ jobs:
             # It will be temporarily activated during tests with locale.setlocale
             extra_loc: "zh_CN"
           - name: "Pypy"
-            env_file: actions-pypy-39.yaml
+            env_file: actions-pypy-310.yaml
             pattern: "not slow and not network and not single_cpu"
             test_args: "--max-worker-restart 0"
           - name: "Numpy Dev"
@@ -170,7 +170,7 @@ jobs:
       matrix:
         # Note: Don't use macOS latest since macos 14 appears to be arm64 only
         os: [macos-13, macos-14, windows-latest]
-        env_file: [actions-39.yaml, actions-310.yaml, actions-311.yaml, actions-312.yaml]
+        env_file: [actions-310.yaml, actions-311.yaml, actions-312.yaml]
       fail-fast: false
     runs-on: ${{ matrix.os }}
     name: ${{ format('{0} {1}', matrix.os, matrix.env_file) }}

.github/workflows/wheels.yml

@@ -99,7 +99,7 @@ jobs:
         - [macos-14, macosx_arm64]
         - [windows-2022, win_amd64]
         # TODO: support PyPy?
-        python: [["cp39", "3.9"], ["cp310", "3.10"], ["cp311", "3.11"], ["cp312", "3.12"]]
+        python: [["cp310", "3.10"], ["cp311", "3.11"], ["cp312", "3.12"]]
     env:
       IS_PUSH: ${{ github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v') }}
       IS_SCHEDULE_DISPATCH: ${{ github.event_name == 'schedule' || github.event_name == 'workflow_dispatch' }}

ci/deps/actions-39-minimum_versions.yaml → ci/deps/actions-310-minimum_versions.yaml

@@ -4,7 +4,7 @@ name: pandas-dev
 channels:
   - conda-forge
 dependencies:
-  - python=3.9
+  - python=3.10
 
   # build dependencies
   - versioneer[toml]

ci/deps/actions-pypy-39.yaml → ci/deps/actions-pypy-310.yaml

@@ -5,7 +5,7 @@ dependencies:
   # TODO: Add the rest of the dependencies in here
   # once the other plentiful failures/segfaults
   # with base pandas has been dealt with
-  - python=3.9[build=*_pypy]
+  - python=3.10[build=*_pypy]
 
   # build dependencies
   - versioneer[toml]

doc/source/development/contributing_environment.rst

@@ -130,7 +130,7 @@ Consult the docs for setting up pyenv `here <https://github.com/pyenv/pyenv>`__.
    pyenv virtualenv <version> <name-to-give-it>
 
    # For instance:
-   pyenv virtualenv 3.9.10 pandas-dev
+   pyenv virtualenv 3.10 pandas-dev
 
    # Activate the virtualenv
    pyenv activate pandas-dev

doc/source/getting_started/install.rst

@@ -21,7 +21,7 @@ Instructions for installing :ref:`from source <install.source>`,
 Python version support
 ----------------------
 
-Officially Python 3.9, 3.10, 3.11 and 3.12.
+Officially Python 3.10, 3.11 and 3.12.
 
 Installing pandas
 -----------------
@@ -161,7 +161,7 @@ Python terminal.
 
     >>> import pandas as pd
     >>> pd.test()
-    running: pytest -m "not slow and not network and not db" /home/user/anaconda3/lib/python3.9/site-packages/pandas
+    running: pytest -m "not slow and not network and not db" /home/user/anaconda3/lib/python3.10/site-packages/pandas
 
     ============================= test session starts ==============================
     platform linux -- Python 3.9.7, pytest-6.2.5, py-1.11.0, pluggy-1.0.0

doc/source/whatsnew/v3.0.0.rst

@@ -117,6 +117,11 @@ Backwards incompatible API changes
 
 .. _whatsnew_300.api_breaking.deps:
 
+Increased minimum version for Python
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+pandas 3.0.0 supports Python 3.10 and higher.
+
 Increased minimum versions for dependencies
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Some minimum supported versions of dependencies were updated.

pandas/compat/_optional.py

@@ -16,7 +16,7 @@
 if TYPE_CHECKING:
     import types
 
-# Update install.rst, actions-39-minimum_versions.yaml,
+# Update install.rst, actions-310-minimum_versions.yaml,
 # deps_minimum.toml & pyproject.toml when updating versions!
 
 VERSIONS = {

pandas/core/strings/object_array.py

@@ -457,16 +457,7 @@ def _str_rstrip(self, to_strip=None):
         return self._str_map(lambda x: x.rstrip(to_strip))
 
     def _str_removeprefix(self, prefix: str):
-        # outstanding question on whether to use native methods for users on Python 3.9+
-        # https://github.com/pandas-dev/pandas/pull/39226#issuecomment-836719770,
-        # in which case we could do return self._str_map(str.removeprefix)
-
-        def removeprefix(text: str) -> str:
-            if text.startswith(prefix):
-                return text[len(prefix) :]
-            return text
-
-        return self._str_map(removeprefix)
+        return self._str_map(lambda x: x.removeprefix(prefix))
 
     def _str_removesuffix(self, suffix: str):
         return self._str_map(lambda x: x.removesuffix(suffix))

pandas/tests/groupby/test_numeric_only.py

@@ -284,8 +284,7 @@ def test_numeric_only(kernel, has_arg, numeric_only, keys):
             [
                 "not allowed for this dtype",
                 "cannot be performed against 'object' dtypes",
-                # On PY39 message is "a number"; on PY310 and after is "a real number"
-                "must be a string or a.* number",
+                "must be a string or a real number",
                 "unsupported operand type",
                 "function is not implemented for this dtype",
                 re.escape(f"agg function failed [how->{kernel},dtype->object]"),

pyproject.toml

@@ -25,7 +25,7 @@ authors = [
   { name = 'The Pandas Development Team', email='pandas-dev@python.org' },
 ]
 license = {file = 'LICENSE'}
-requires-python = '>=3.9'
+requires-python = '>=3.10'
 dependencies = [
   "numpy>=1.23.5; python_version<'3.12'",
   "numpy>=1.26.0; python_version>='3.12'",
@@ -43,7 +43,6 @@ classifiers = [
     'Programming Language :: Python',
     'Programming Language :: Python :: 3',
     'Programming Language :: Python :: 3 :: Only',
-    'Programming Language :: Python :: 3.9',
     'Programming Language :: Python :: 3.10',
     'Programming Language :: Python :: 3.11',
     'Programming Language :: Python :: 3.12',

scripts/tests/data/deps_minimum.toml

@@ -40,7 +40,6 @@ classifiers = [
     'Programming Language :: Python :: 3',
     'Programming Language :: Python :: 3 :: Only',
     'Programming Language :: Python :: 3.8',
-    'Programming Language :: Python :: 3.9',
     'Programming Language :: Python :: 3.10',
     'Programming Language :: Python :: 3.11',
     'Topic :: Scientific/Engineering'