feat: remove Python 3.7 support

.github/workflows/ci.yml

@@ -311,11 +311,6 @@ jobs:
       fail-fast: false
       matrix:
         clang:
-          - 3.6
-          - 3.7
-          - 3.9
-          - 7
-          - 9
           - dev
         std:
           - 11
@@ -324,8 +319,6 @@ jobs:
         include:
           - clang: 5
             std: 14
-          - clang: 10
-            std: 17
           - clang: 11
             std: 20
           - clang: 12
@@ -503,10 +496,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { gcc: 7, std: 11 }
-          - { gcc: 7, std: 17 }
-          - { gcc: 8, std: 14 }
-          - { gcc: 8, std: 17 }
           - { gcc: 9, std: 20 }
           - { gcc: 10, std: 17 }
           - { gcc: 10, std: 20 }
@@ -727,9 +716,9 @@ jobs:
 
   # This tests an "install" with the CMake tools
   install-classic:
-    name: "🐍 3.7 • Debian • x86 •  Install"
+    name: "🐍 3.9 • Debian • x86 •  Install"
     runs-on: ubuntu-latest
-    container: i386/debian:buster
+    container: i386/debian:bullseye
 
     steps:
     - uses: actions/checkout@v1  # v1 is required to run inside docker
@@ -809,7 +798,6 @@ jobs:
       fail-fast: false
       matrix:
         python:
-        - '3.7'
         - '3.8'
         - '3.9'
         - '3.10'
@@ -827,8 +815,6 @@ jobs:
             args: -DCMAKE_CXX_STANDARD=20
           - python: '3.8'
             args: -DCMAKE_CXX_STANDARD=17
-          - python: '3.7'
-            args: -DCMAKE_CXX_STANDARD=14
 
 
     name: "🐍 ${{ matrix.python }} • MSVC 2019 • x86 ${{ matrix.args }}"

.github/workflows/configure.yml

@@ -39,22 +39,22 @@ jobs:
 
         - runs-on: macos-13
           arch: x64
-          cmake: "3.7"
+          cmake: "3.8"
 
         - runs-on: windows-2019
           arch: x64 # x86 compilers seem to be missing on 2019 image
           cmake: "3.18"
 
-    name: 🐍 3.7 • CMake ${{ matrix.cmake }} • ${{ matrix.runs-on }}
+    name: 🐍 3.8 • CMake ${{ matrix.cmake }} • ${{ matrix.runs-on }}
     runs-on: ${{ matrix.runs-on }}
 
     steps:
     - uses: actions/checkout@v4
 
-    - name: Setup Python 3.7
+    - name: Setup Python 3.8
       uses: actions/setup-python@v5
       with:
-        python-version: 3.7
+        python-version: 3.8
         architecture: ${{ matrix.arch }}
 
     - name: Prepare env

README.rst

@@ -34,7 +34,7 @@ dependency.
 Think of this library as a tiny self-contained version of Boost.Python
 with everything stripped away that isn't relevant for binding
 generation. Without comments, the core header files only require ~4K
-lines of code and depend on Python (3.7+, or PyPy) and the C++
+lines of code and depend on Python (3.8+, or PyPy) and the C++
 standard library. This compact implementation was possible thanks to
 some C++11 language features (specifically: tuples, lambda functions and
 variadic templates). Since its creation, this library has grown beyond
@@ -79,7 +79,7 @@ Goodies
 In addition to the core functionality, pybind11 provides some extra
 goodies:
 
-- Python 3.7+, and PyPy3 7.3 are supported with an implementation-agnostic
+- Python 3.8+, and PyPy3 7.3 are supported with an implementation-agnostic
   interface (pybind11 2.9 was the last version to support Python 2 and 3.5).
 
 - It is possible to bind C++11 lambda functions with captured

docs/advanced/classes.rst

@@ -826,8 +826,7 @@ An instance can now be pickled as follows:
     always use the latest available version. Beware: failure to follow these
     instructions will cause important pybind11 memory allocation routines to be
     skipped during unpickling, which will likely lead to memory corruption
-    and/or segmentation faults. Python defaults to version 3 (Python 3-3.7) and
-    version 4 for Python 3.8+.
+    and/or segmentation faults.
 
 .. seealso::
 

docs/advanced/exceptions.rst

@@ -368,8 +368,7 @@ Should they throw or fail to catch any exceptions in their call graph,
 the C++ runtime calls ``std::terminate()`` to abort immediately.
 
 Similarly, Python exceptions raised in a class's ``__del__`` method do not
-propagate, but are logged by Python as an unraisable error. In Python 3.8+, a
-`system hook is triggered
+propagate, but ``sys.unraisablehook()`` `is triggered
 <https://docs.python.org/3/library/sys.html#sys.unraisablehook>`_
 and an auditing event is logged.
 

docs/compiling.rst

@@ -426,7 +426,7 @@ with ``PYTHON_EXECUTABLE``.  For example:
 
 .. code-block:: bash
 
-    cmake -DPYBIND11_PYTHON_VERSION=3.7 ..
+    cmake -DPYBIND11_PYTHON_VERSION=3.8 ..
 
     # Another method:
     cmake -DPYTHON_EXECUTABLE=/path/to/python ..
@@ -493,7 +493,7 @@ existing targets instead:
     cmake_minimum_required(VERSION 3.15...3.22)
     project(example LANGUAGES CXX)
 
-    find_package(Python 3.7 COMPONENTS Interpreter Development REQUIRED)
+    find_package(Python 3.8 COMPONENTS Interpreter Development REQUIRED)
     find_package(pybind11 CONFIG REQUIRED)
     # or add_subdirectory(pybind11)
 

include/pybind11/cast.h

@@ -158,7 +158,7 @@ struct type_caster<T, enable_if_t<std::is_arithmetic<T>::value && !is_std_char_t
         } else {
             handle src_or_index = src;
             // PyPy: 7.3.7's 3.8 does not implement PyLong_*'s __index__ calls.
-#if PY_VERSION_HEX < 0x03080000 || defined(PYPY_VERSION)
+#if defined(PYPY_VERSION)
             object index;
             if (!PYBIND11_LONG_CHECK(src.ptr())) { // So: index_check(src.ptr())
                 index = reinterpret_steal<object>(PyNumber_Index(src.ptr()));
@@ -1503,7 +1503,7 @@ struct kw_only {};
 
 /// \ingroup annotations
 /// Annotation indicating that all previous arguments are positional-only; the is the equivalent of
-/// an unnamed '/' argument (in Python 3.8)
+/// an unnamed '/' argument
 struct pos_only {};
 
 template <typename T>

include/pybind11/detail/class.h

@@ -466,19 +466,9 @@ extern "C" inline void pybind11_object_dealloc(PyObject *self) {
 
     type->tp_free(self);
 
-#if PY_VERSION_HEX < 0x03080000
-    // `type->tp_dealloc != pybind11_object_dealloc` means that we're being called
-    // as part of a derived type's dealloc, in which case we're not allowed to decref
-    // the type here. For cross-module compatibility, we shouldn't compare directly
-    // with `pybind11_object_dealloc`, but with the common one stashed in internals.
-    auto pybind11_object_type = (PyTypeObject *) get_internals().instance_base;
-    if (type->tp_dealloc == pybind11_object_type->tp_dealloc)
-        Py_DECREF(type);
-#else
     // This was not needed before Python 3.8 (Python issue 35810)
     // https://github.com/pybind/pybind11/issues/1946
     Py_DECREF(type);
-#endif
 }
 
 std::string error_string();

include/pybind11/detail/common.h

@@ -272,8 +272,8 @@ PYBIND11_WARNING_DISABLE_MSVC(4505)
 #endif
 
 #include <Python.h>
-#if PY_VERSION_HEX < 0x03070000
-#    error "PYTHON < 3.7 IS UNSUPPORTED. pybind11 v2.12 was the last to support Python 3.6."
+#if PY_VERSION_HEX < 0x03080000
+#    error "PYTHON < 3.8 IS UNSUPPORTED. pybind11 v2.13 was the last to support Python 3.7."
 #endif
 #include <frameobject.h>
 #include <pythread.h>

include/pybind11/detail/internals.h

@@ -447,7 +447,7 @@ inline void translate_local_exception(std::exception_ptr p) {
 
 inline object get_python_state_dict() {
     object state_dict;
-#if PYBIND11_INTERNALS_VERSION <= 4 || PY_VERSION_HEX < 0x03080000 || defined(PYPY_VERSION)
+#if PYBIND11_INTERNALS_VERSION <= 4 || defined(PYPY_VERSION)
     state_dict = reinterpret_borrow<object>(PyEval_GetBuiltins());
 #else
 #    if PY_VERSION_HEX < 0x03090000

include/pybind11/embed.h

@@ -104,23 +104,13 @@ inline void initialize_interpreter_pre_pyconfig(bool init_signal_handlers,
     detail::precheck_interpreter();
     Py_InitializeEx(init_signal_handlers ? 1 : 0);
 
-    // Before it was special-cased in python 3.8, passing an empty or null argv
-    // caused a segfault, so we have to reimplement the special case ourselves.
-    bool special_case = (argv == nullptr || argc <= 0);
-
-    const char *const empty_argv[]{"\0"};
-    const char *const *safe_argv = special_case ? empty_argv : argv;
-    if (special_case) {
-        argc = 1;
-    }
-
     auto argv_size = static_cast<size_t>(argc);
     // SetArgv* on python 3 takes wchar_t, so we have to convert.
     std::unique_ptr<wchar_t *[]> widened_argv(new wchar_t *[argv_size]);
     std::vector<std::unique_ptr<wchar_t[], detail::wide_char_arg_deleter>> widened_argv_entries;
     widened_argv_entries.reserve(argv_size);
     for (size_t ii = 0; ii < argv_size; ++ii) {
-        widened_argv_entries.emplace_back(detail::widen_chars(safe_argv[ii]));
+        widened_argv_entries.emplace_back(detail::widen_chars(argv[ii]));
         if (!widened_argv_entries.back()) {
             // A null here indicates a character-encoding failure or the python
             // interpreter out of memory. Give up.

include/pybind11/eval.h

@@ -19,7 +19,7 @@ PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 inline void ensure_builtins_in_globals(object &global) {
-#if defined(PYPY_VERSION) || PY_VERSION_HEX < 0x03080000
+#if defined(PYPY_VERSION)
     // Running exec and eval adds `builtins` module under `__builtins__` key to
     // globals if not yet present.  Python 3.8 made PyRun_String behave
     // similarly. Let's also do that for older versions, for consistency. This

include/pybind11/gil.h

@@ -147,9 +147,7 @@ class gil_scoped_release {
         // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
         tstate = PyEval_SaveThread();
         if (disassoc) {
-            // Python >= 3.7 can remove this, it's an int before 3.7
-            // NOLINTNEXTLINE(readability-qualified-auto)
-            auto key = internals.tstate;
+            auto key = internals.tstate; // NOLINT(readability-qualified-auto)
             PYBIND11_TLS_DELETE_VALUE(key);
         }
     }
@@ -173,9 +171,7 @@ class gil_scoped_release {
             PyEval_RestoreThread(tstate);
         }
         if (disassoc) {
-            // Python >= 3.7 can remove this, it's an int before 3.7
-            // NOLINTNEXTLINE(readability-qualified-auto)
-            auto key = detail::get_internals().tstate;
+            auto key = detail::get_internals().tstate; // NOLINT(readability-qualified-auto)
             PYBIND11_TLS_REPLACE_VALUE(key, tstate);
         }
     }

pybind11/__init__.py

@@ -2,8 +2,8 @@
 
 import sys
 
-if sys.version_info < (3, 7):  # noqa: UP036
-    msg = "pybind11 does not support Python < 3.7. v2.12 was the last release supporting Python 3.6."
+if sys.version_info < (3, 8):  # noqa: UP036
+    msg = "pybind11 does not support Python < 3.8. v2.13 was the last release supporting Python 3.7."
     raise ImportError(msg)
 
 

pybind11/setup_helpers.py

@@ -249,7 +249,7 @@ def has_flag(compiler: Any, flag: str) -> bool:
 cpp_flag_cache = None
 
 
-@lru_cache()
+@lru_cache
 def auto_cpp_level(compiler: Any) -> str | int:
     """
     Return the max supported C++ std level (17, 14, or 11). Returns latest on Windows.

pyproject.toml

@@ -30,7 +30,7 @@ ignore_missing_imports = true
 
 
 [tool.pylint]
-master.py-version = "3.7"
+master.py-version = "3.8"
 reports.output-format = "colorized"
 messages_control.disable = [
   "design",
@@ -45,7 +45,7 @@ messages_control.disable = [
 ]
 
 [tool.ruff]
-target-version = "py37"
+target-version = "py38"
 src = ["src"]
 
 [tool.ruff.lint]

setup.cfg

@@ -14,7 +14,6 @@ classifiers =
     Topic :: Utilities
     Programming Language :: C++
     Programming Language :: Python :: 3 :: Only
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
@@ -39,5 +38,5 @@ project_urls =
     Chat = https://gitter.im/pybind/Lobby
 
 [options]
-python_requires = >=3.7
+python_requires = >=3.8
 zip_safe = False

tests/requirements.txt

@@ -1,9 +1,8 @@
 --only-binary=:all:
-build~=1.0; python_version>="3.7"
-numpy~=1.20.0; python_version=="3.7" and platform_python_implementation=="PyPy"
+build~=1.0; python_version>="3.8"
 numpy~=1.23.0; python_version=="3.8" and platform_python_implementation=="PyPy"
 numpy~=1.25.0; python_version=="3.9" and platform_python_implementation=='PyPy'
-numpy~=1.21.5; platform_python_implementation!="PyPy" and python_version>="3.7" and python_version<"3.10"
+numpy~=1.21.5; platform_python_implementation!="PyPy" and python_version>="3.8" and python_version<"3.10"
 numpy~=1.22.2; platform_python_implementation!="PyPy" and python_version=="3.10"
 numpy~=1.26.0; platform_python_implementation!="PyPy" and python_version>="3.11" and python_version<"3.13"
 pytest~=7.0

tests/test_builtin_casters.py

@@ -297,7 +297,7 @@ def cant_convert(v):
     cant_convert(3.14159)
     # TODO: Avoid DeprecationWarning in `PyLong_AsLong` (and similar)
     # TODO: PyPy 3.8 does not behave like CPython 3.8 here yet (7.3.7)
-    if (3, 8) <= sys.version_info < (3, 10) and env.CPYTHON:
+    if sys.version_info < (3, 10) and env.CPYTHON:
         with env.deprecated_call():
             assert convert(Int()) == 42
     else:

tests/test_exceptions.py

@@ -103,28 +103,24 @@ def ignore_pytest_unraisable_warning(f):
 @pytest.mark.xfail(env.PYPY, reason="Failure on PyPy 3.8 (7.3.7)", strict=False)
 @ignore_pytest_unraisable_warning
 def test_python_alreadyset_in_destructor(monkeypatch, capsys):
-    hooked = False
     triggered = False
 
-    if hasattr(sys, "unraisablehook"):  # Python 3.8+
-        hooked = True
-        # Don't take `sys.unraisablehook`, as that's overwritten by pytest
-        default_hook = sys.__unraisablehook__
+    # Don't take `sys.unraisablehook`, as that's overwritten by pytest
+    default_hook = sys.__unraisablehook__
 
-        def hook(unraisable_hook_args):
-            exc_type, exc_value, exc_tb, err_msg, obj = unraisable_hook_args
-            if obj == "already_set demo":
-                nonlocal triggered
-                triggered = True
-            default_hook(unraisable_hook_args)
-            return
+    def hook(unraisable_hook_args):
+        exc_type, exc_value, exc_tb, err_msg, obj = unraisable_hook_args
+        if obj == "already_set demo":
+            nonlocal triggered
+            triggered = True
+        default_hook(unraisable_hook_args)
+        return
 
-        # Use monkeypatch so pytest can apply and remove the patch as appropriate
-        monkeypatch.setattr(sys, "unraisablehook", hook)
+    # Use monkeypatch so pytest can apply and remove the patch as appropriate
+    monkeypatch.setattr(sys, "unraisablehook", hook)
 
     assert m.python_alreadyset_in_destructor("already_set demo") is True
-    if hooked:
-        assert triggered is True
+    assert triggered is True
 
     _, captured_stderr = capsys.readouterr()
     assert captured_stderr.startswith("Exception ignored in: 'already_set demo'")

tools/FindPythonLibsNew.cmake

@@ -92,7 +92,7 @@ endif()
 
 # Use the Python interpreter to find the libs.
 if(NOT PythonLibsNew_FIND_VERSION)
-  set(PythonLibsNew_FIND_VERSION "3.7")
+  set(PythonLibsNew_FIND_VERSION "3.8")
 endif()
 
 if(NOT CMAKE_VERSION VERSION_LESS "3.27")

tools/pybind11NewTools.cmake

@@ -56,7 +56,7 @@ if(NOT Python_FOUND AND NOT Python3_FOUND)
   endif()
 
   find_package(
-    Python 3.7 REQUIRED COMPONENTS ${_pybind11_interp_component} ${_pybind11_dev_component}
+    Python 3.8 REQUIRED COMPONENTS ${_pybind11_interp_component} ${_pybind11_dev_component}
                                    ${_pybind11_quiet} ${_pybind11_global_keyword})
 
   # If we are in submodule mode, export the Python targets to global targets.

tools/pybind11Tools.cmake

@@ -43,7 +43,7 @@ endif()
 
 # A user can set versions manually too
 set(Python_ADDITIONAL_VERSIONS
-    "3.12;3.11;3.10;3.9;3.8;3.7"
+    "3.12;3.11;3.10;3.9;3.8"
     CACHE INTERNAL "")
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")