[2.3.x] DEPS: Drop Python 3.9 (#60792)

Author: jorisvandenbossche

.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

@@ -27,7 +27,7 @@ jobs:
     strategy:
       matrix:
         platform: [ubuntu-22.04, ubuntu-24.04-arm]
-        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: [""]
         pandas_future_infer_string: ["0"]
@@ -38,7 +38,7 @@ jobs:
             pytest_target: "pandas/tests/test_downstream.py"
             platform: ubuntu-22.04
           - 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"
             platform: ubuntu-22.04
           - name: "Locale: it_IT"
@@ -63,11 +63,6 @@ jobs:
             # It will be temporarily activated during tests with locale.setlocale
             extra_loc: "zh_CN"
             platform: ubuntu-22.04
-          - name: "Copy-on-Write 3.9"
-            env_file: actions-39.yaml
-            pattern: "not slow and not network and not single_cpu"
-            pandas_copy_on_write: "1"
-            platform: ubuntu-22.04
           - name: "Copy-on-Write 3.10"
             env_file: actions-310.yaml
             pattern: "not slow and not network and not single_cpu"
@@ -93,11 +88,6 @@ jobs:
             pattern: "not slow and not network and not single_cpu"
             pandas_copy_on_write: "warn"
             platform: ubuntu-22.04
-          - name: "Copy-on-Write 3.9 (warnings)"
-            env_file: actions-39.yaml
-            pattern: "not slow and not network and not single_cpu"
-            pandas_copy_on_write: "warn"
-            platform: ubuntu-22.04
           - name: "Future infer strings"
             env_file: actions-312.yaml
             pandas_future_infer_string: "1"
@@ -228,7 +218,7 @@ 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

@@ -100,7 +100,7 @@ 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"], ["cp313", "3.13"], ["cp313t", "3.13"]]
+        python: [["cp310", "3.10"], ["cp311", "3.11"], ["cp312", "3.12"], ["cp313", "3.13"], ["cp313t", "3.13"]]
         include:
         # TODO: Remove this plus installing build deps in cibw_before_build.sh
         # after pandas can be built with a released NumPy/Cython

ci/deps/actions-39-minimum_versions.yaml renamed to 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

ci/deps/actions-39.yaml

@@ -52,6 +52,12 @@ These are bug fixes that might have notable behavior changes.
 notable_bug_fix1
 ^^^^^^^^^^^^^^^^
 
+
+Increased minimum version for Python
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+pandas 2.3.0 supports Python 3.10 and higher.
+
 .. ---------------------------------------------------------------------------
 .. _whatsnew_230.deprecations: