MAINT Drop official PyPy support (scikit-learn#29128)

Author: lesteve

.github/workflows/update-lock-files.yml

@@ -25,9 +25,6 @@ jobs:
           - name: cirrus-arm
             update_script_args: "--select-tag arm"
             additional_commit_message: "[cirrus arm]"
-          - name: pypy
-            update_script_args: "--select-tag pypy"
-            additional_commit_message: "[pypy]"
 
     steps:
       - uses: actions/checkout@v4

azure-pipelines.yml

@@ -98,27 +98,6 @@ jobs:
         LOCK_FILE: './build_tools/azure/python_nogil_lock.txt'
         COVERAGE: 'false'
 
-- template: build_tools/azure/posix-docker.yml
-  parameters:
-    name: Linux_Nightly_PyPy
-    vmImage: ubuntu-20.04
-    dependsOn: [linting, git_commit]
-    condition: |
-      and(
-        succeeded(),
-        not(contains(dependencies['git_commit']['outputs']['commit.message'], '[ci skip]')),
-        or(
-          eq(variables['Build.Reason'], 'Schedule'),
-          contains(dependencies['git_commit']['outputs']['commit.message'], '[pypy]')
-        )
-      )
-    matrix:
-      pypy3:
-        DOCKER_CONTAINER: 'condaforge/miniforge3:4.10.3-5'
-        DISTRIB: 'conda-pypy3'
-        LOCK_FILE: './build_tools/azure/pypy3_linux-64_conda.lock'
-
-
 - job: Linux_Nightly_Pyodide
   pool:
     vmImage: ubuntu-22.04

build_tools/azure/install.sh

@@ -38,13 +38,7 @@ pre_python_environment_install() {
         apt-get install -y python3-dev python3-numpy python3-scipy \
                 python3-matplotlib libatlas3-base libatlas-base-dev \
                 python3-virtualenv python3-pandas ccache git
-
-    elif [[ "$DISTRIB" == "conda-pypy3" ]]; then
-        # need compilers
-        apt-get -yq update
-        apt-get -yq install build-essential
     fi
-
 }
 
 check_packages_dev_version() {

build_tools/azure/pypy3_environment.yml

@@ -61,13 +61,6 @@ if [[ -n "$SELECTED_TESTS" ]]; then
 fi
 
 TEST_CMD="$TEST_CMD --pyargs sklearn"
-if [[ "$DISTRIB" == "conda-pypy3" ]]; then
-    # Run only common tests for PyPy. Running the full test suite uses too
-    # much memory and causes the test to time out sometimes. See
-    # https://github.com/scikit-learn/scikit-learn/issues/27662 for more
-    # details.
-    TEST_CMD="$TEST_CMD.tests.test_common"
-fi
 
 set -x
 eval "$TEST_CMD"

build_tools/azure/pypy3_linux-64_conda.lock

@@ -245,25 +245,6 @@ def remove_from(alist, to_remove):
             + ["python-dateutil"]
         ),
     },
-    {
-        "name": "pypy3",
-        "type": "conda",
-        "tag": "pypy",
-        "folder": "build_tools/azure",
-        "platform": "linux-64",
-        "channel": "conda-forge",
-        "conda_dependencies": (
-            ["pypy", "python"]
-            + remove_from(
-                common_dependencies_without_coverage, ["python", "pandas", "pillow"]
-            )
-            + ["ccache"]
-        ),
-        "package_constraints": {
-            "blas": "[build=openblas]",
-            "python": "3.9",
-        },
-    },
     {
         "name": "pymin_conda_forge_mkl",
         "type": "conda",

build_tools/azure/test_script.sh

@@ -10,7 +10,7 @@
 from sklearn.datasets._base import _pkl_filepath
 from sklearn.datasets._twenty_newsgroups import CACHE_NAME
 from sklearn.utils._testing import SkipTest, check_skip_network
-from sklearn.utils.fixes import _IS_PYPY, np_base_version, parse_version
+from sklearn.utils.fixes import np_base_version, parse_version
 
 
 def setup_labeled_faces():
@@ -34,8 +34,6 @@ def setup_twenty_newsgroups():
 
 
 def setup_working_with_text_data():
-    if _IS_PYPY and os.environ.get("CI", None):
-        raise SkipTest("Skipping too slow test with PyPy on CI")
     check_skip_network()
     cache_path = _pkl_filepath(get_data_home(), CACHE_NAME)
     if not exists(cache_path):

build_tools/update_environments_and_lock_files.py

@@ -519,7 +519,6 @@ Commit Message Marker  Action Taken by CI
 [lint skip]            Azure pipeline skips linting
 [scipy-dev]            Build & test with our dependencies (numpy, scipy, etc.) development builds
 [nogil]                Build & test with the nogil experimental branches of CPython, Cython, NumPy, SciPy, ...
-[pypy]                 Build & test with PyPy
 [pyodide]              Build & test with Pyodide
 [azure parallel]       Run Azure CI jobs in parallel
 [cirrus arm]           Run Cirrus CI ARM test

doc/conftest.py

@@ -62,13 +62,10 @@ Apart from scikit-learn, another popular one is `scikit-image <https://scikit-im
 Do you support PyPy?
 ^^^^^^^^^^^^^^^^^^^^
 
-scikit-learn is regularly tested and maintained to work with
-`PyPy <https://pypy.org/>`_ (an alternative Python implementation with
-a built-in just-in-time compiler).
-
-Note however that this support is still considered experimental and specific
-components might behave slightly differently. Please refer to the test
-suite of the specific module of interest for more details.
+Due to limited maintainer resources and small number of users, using
+scikit-learn with `PyPy <https://pypy.org/>`_ (an alternative Python
+implementation with a built-in just-in-time compiler) is not officially
+supported.
 
 How can I obtain permission to use the images in scikit-learn for my work?
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^