| .. highlight:: c |
| |
| .. _init-config: |
| |
| *********************************** |
| Python Initialization Configuration |
| *********************************** |
| |
| .. versionadded:: 3.8 |
| |
| Python can be initialized with :c:func:`Py_InitializeFromConfig` and the |
| :c:type:`PyConfig` structure. It can be preinitialized with |
| :c:func:`Py_PreInitialize` and the :c:type:`PyPreConfig` structure. |
| |
| There are two kinds of configuration: |
| |
| * The :ref:`Python Configuration <init-python-config>` can be used to build a |
| customized Python which behaves as the regular Python. For example, |
| environments variables and command line arguments are used to configure |
| Python. |
| |
| * The :ref:`Isolated Configuration <init-isolated-conf>` can be used to embed |
| Python into an application. It isolates Python from the system. For example, |
| environments variables are ignored, the LC_CTYPE locale is left unchanged and |
| no signal handler is registred. |
| |
| See also :ref:`Initialization, Finalization, and Threads <initialization>`. |
| |
| .. seealso:: |
| :pep:`587` "Python Initialization Configuration". |
| |
| Example |
| ======= |
| |
| Example of customized Python always running in isolated mode:: |
| |
| int main(int argc, char **argv) |
| { |
| PyStatus status; |
| |
| PyConfig config; |
| PyConfig_InitPythonConfig(&config); |
| config.isolated = 1; |
| |
| /* Decode command line arguments. |
| Implicitly preinitialize Python (in isolated mode). */ |
| status = PyConfig_SetBytesArgv(&config, argc, argv); |
| if (PyStatus_Exception(status)) { |
| goto exception; |
| } |
| |
| status = Py_InitializeFromConfig(&config); |
| if (PyStatus_Exception(status)) { |
| goto exception; |
| } |
| PyConfig_Clear(&config); |
| |
| return Py_RunMain(); |
| |
| exception: |
| PyConfig_Clear(&config); |
| if (PyStatus_IsExit(status)) { |
| return status.exitcode; |
| } |
| /* Display the error message and exit the process with |
| non-zero exit code */ |
| Py_ExitStatusException(status); |
| } |
| |
| |
| PyWideStringList |
| ================ |
| |
| .. c:type:: PyWideStringList |
| |
| List of ``wchar_t*`` strings. |
| |
| If *length* is non-zero, *items* must be non-``NULL`` and all strings must be |
| non-``NULL``. |
| |
| Methods: |
| |
| .. c:function:: PyStatus PyWideStringList_Append(PyWideStringList *list, const wchar_t *item) |
| |
| Append *item* to *list*. |
| |
| Python must be preinitialized to call this function. |
| |
| .. c:function:: PyStatus PyWideStringList_Insert(PyWideStringList *list, Py_ssize_t index, const wchar_t *item) |
| |
| Insert *item* into *list* at *index*. |
| |
| If *index* is greater than or equal to *list* length, append *item* to |
| *list*. |
| |
| *index* must be greater than or equal to 0. |
| |
| Python must be preinitialized to call this function. |
| |
| Structure fields: |
| |
| .. c:member:: Py_ssize_t length |
| |
| List length. |
| |
| .. c:member:: wchar_t** items |
| |
| List items. |
| |
| PyStatus |
| ======== |
| |
| .. c:type:: PyStatus |
| |
| Structure to store an initialization function status: success, error |
| or exit. |
| |
| For an error, it can store the C function name which created the error. |
| |
| Structure fields: |
| |
| .. c:member:: int exitcode |
| |
| Exit code. Argument passed to ``exit()``. |
| |
| .. c:member:: const char *err_msg |
| |
| Error message. |
| |
| .. c:member:: const char *func |
| |
| Name of the function which created an error, can be ``NULL``. |
| |
| Functions to create a status: |
| |
| .. c:function:: PyStatus PyStatus_Ok(void) |
| |
| Success. |
| |
| .. c:function:: PyStatus PyStatus_Error(const char *err_msg) |
| |
| Initialization error with a message. |
| |
| *err_msg* must not be ``NULL``. |
| |
| .. c:function:: PyStatus PyStatus_NoMemory(void) |
| |
| Memory allocation failure (out of memory). |
| |
| .. c:function:: PyStatus PyStatus_Exit(int exitcode) |
| |
| Exit Python with the specified exit code. |
| |
| Functions to handle a status: |
| |
| .. c:function:: int PyStatus_Exception(PyStatus status) |
| |
| Is the status an error or an exit? If true, the exception must be |
| handled; by calling :c:func:`Py_ExitStatusException` for example. |
| |
| .. c:function:: int PyStatus_IsError(PyStatus status) |
| |
| Is the result an error? |
| |
| .. c:function:: int PyStatus_IsExit(PyStatus status) |
| |
| Is the result an exit? |
| |
| .. c:function:: void Py_ExitStatusException(PyStatus status) |
| |
| Call ``exit(exitcode)`` if *status* is an exit. Print the error |
| message and exit with a non-zero exit code if *status* is an error. Must |
| only be called if ``PyStatus_Exception(status)`` is non-zero. |
| |
| .. note:: |
| Internally, Python uses macros which set ``PyStatus.func``, |
| whereas functions to create a status set ``func`` to ``NULL``. |
| |
| Example:: |
| |
| PyStatus alloc(void **ptr, size_t size) |
| { |
| *ptr = PyMem_RawMalloc(size); |
| if (*ptr == NULL) { |
| return PyStatus_NoMemory(); |
| } |
| return PyStatus_Ok(); |
| } |
| |
| int main(int argc, char **argv) |
| { |
| void *ptr; |
| PyStatus status = alloc(&ptr, 16); |
| if (PyStatus_Exception(status)) { |
| Py_ExitStatusException(status); |
| } |
| PyMem_Free(ptr); |
| return 0; |
| } |
| |
| |
| PyPreConfig |
| =========== |
| |
| .. c:type:: PyPreConfig |
| |
| Structure used to preinitialize Python. |
| |
| Function to initialize a preconfiguration: |
| |
| .. c:function:: void PyPreConfig_InitPythonConfig(PyPreConfig *preconfig) |
| |
| Initialize the preconfiguration with :ref:`Python Configuration |
| <init-python-config>`. |
| |
| .. c:function:: void PyPreConfig_InitIsolatedConfig(PyPreConfig *preconfig) |
| |
| Initialize the preconfiguration with :ref:`Isolated Configuration |
| <init-isolated-conf>`. |
| |
| Structure fields: |
| |
| .. c:member:: int allocator |
| |
| Name of the Python memory allocators: |
| |
| * ``PYMEM_ALLOCATOR_NOT_SET`` (``0``): don't change memory allocators |
| (use defaults) |
| * ``PYMEM_ALLOCATOR_DEFAULT`` (``1``): default memory allocators |
| * ``PYMEM_ALLOCATOR_DEBUG`` (``2``): default memory allocators with |
| debug hooks |
| * ``PYMEM_ALLOCATOR_MALLOC`` (``3``): force usage of ``malloc()`` |
| * ``PYMEM_ALLOCATOR_MALLOC_DEBUG`` (``4``): force usage of |
| ``malloc()`` with debug hooks |
| * ``PYMEM_ALLOCATOR_PYMALLOC`` (``5``): :ref:`Python pymalloc memory |
| allocator <pymalloc>` |
| * ``PYMEM_ALLOCATOR_PYMALLOC_DEBUG`` (``6``): :ref:`Python pymalloc |
| memory allocator <pymalloc>` with debug hooks |
| |
| ``PYMEM_ALLOCATOR_PYMALLOC`` and ``PYMEM_ALLOCATOR_PYMALLOC_DEBUG`` |
| are not supported if Python is configured using ``--without-pymalloc`` |
| |
| See :ref:`Memory Management <memory>`. |
| |
| Default: ``PYMEM_ALLOCATOR_NOT_SET``. |
| |
| .. c:member:: int configure_locale |
| |
| Set the LC_CTYPE locale to the user preferred locale? |
| |
| If equals to 0, set :c:member:`~PyPreConfig.coerce_c_locale` and |
| :c:member:`~PyPreConfig.coerce_c_locale_warn` members to 0. |
| |
| See the :term:`locale encoding`. |
| |
| Default: ``1`` in Python config, ``0`` in isolated config. |
| |
| .. c:member:: int coerce_c_locale |
| |
| If equals to 2, coerce the C locale. |
| |
| If equals to 1, read the LC_CTYPE locale to decide if it should be |
| coerced. |
| |
| See the :term:`locale encoding`. |
| |
| Default: ``-1`` in Python config, ``0`` in isolated config. |
| |
| .. c:member:: int coerce_c_locale_warn |
| |
| If non-zero, emit a warning if the C locale is coerced. |
| |
| Default: ``-1`` in Python config, ``0`` in isolated config. |
| |
| .. c:member:: int dev_mode |
| |
| If non-zero, enables the :ref:`Python Development Mode <devmode>`: |
| see :c:member:`PyConfig.dev_mode`. |
| |
| Default: ``-1`` in Python mode, ``0`` in isolated mode. |
| |
| .. c:member:: int isolated |
| |
| Isolated mode: see :c:member:`PyConfig.isolated`. |
| |
| Default: ``0`` in Python mode, ``1`` in isolated mode. |
| |
| .. c:member:: int legacy_windows_fs_encoding |
| |
| If non-zero: |
| |
| * Set :c:member:`PyPreConfig.utf8_mode` to ``0``, |
| * Set :c:member:`PyConfig.filesystem_encoding` to ``"mbcs"``, |
| * Set :c:member:`PyConfig.filesystem_errors` to ``"replace"``. |
| |
| Initialized the from :envvar:`PYTHONLEGACYWINDOWSFSENCODING` environment |
| variable value. |
| |
| Only available on Windows. ``#ifdef MS_WINDOWS`` macro can be used for |
| Windows specific code. |
| |
| Default: ``0``. |
| |
| .. c:member:: int parse_argv |
| |
| If non-zero, :c:func:`Py_PreInitializeFromArgs` and |
| :c:func:`Py_PreInitializeFromBytesArgs` parse their ``argv`` argument the |
| same way the regular Python parses command line arguments: see |
| :ref:`Command Line Arguments <using-on-cmdline>`. |
| |
| Default: ``1`` in Python config, ``0`` in isolated config. |
| |
| .. c:member:: int use_environment |
| |
| Use :ref:`environment variables <using-on-envvars>`? See |
| :c:member:`PyConfig.use_environment`. |
| |
| Default: ``1`` in Python config and ``0`` in isolated config. |
| |
| .. c:member:: int utf8_mode |
| |
| If non-zero, enable the :ref:`Python UTF-8 Mode <utf8-mode>`. |
| |
| Set by the :option:`-X utf8 <-X>` command line option and the |
| :envvar:`PYTHONUTF8` environment variable. |
| |
| Default: ``-1`` in Python config and ``0`` in isolated config. |
| |
| |
| .. _c-preinit: |
| |
| Preinitialize Python with PyPreConfig |
| ===================================== |
| |
| The preinitialization of Python: |
| |
| * Set the Python memory allocators (:c:member:`PyPreConfig.allocator`) |
| * Configure the LC_CTYPE locale (:term:`locale encoding`) |
| * Set the :ref:`Python UTF-8 Mode <utf8-mode>` |
| (:c:member:`PyPreConfig.utf8_mode`) |
| |
| The current preconfiguration (``PyPreConfig`` type) is stored in |
| ``_PyRuntime.preconfig``. |
| |
| Functions to preinitialize Python: |
| |
| .. c:function:: PyStatus Py_PreInitialize(const PyPreConfig *preconfig) |
| |
| Preinitialize Python from *preconfig* preconfiguration. |
| |
| *preconfig* must not be ``NULL``. |
| |
| .. c:function:: PyStatus Py_PreInitializeFromBytesArgs(const PyPreConfig *preconfig, int argc, char * const *argv) |
| |
| Preinitialize Python from *preconfig* preconfiguration. |
| |
| Parse *argv* command line arguments (bytes strings) if |
| :c:member:`~PyPreConfig.parse_argv` of *preconfig* is non-zero. |
| |
| *preconfig* must not be ``NULL``. |
| |
| .. c:function:: PyStatus Py_PreInitializeFromArgs(const PyPreConfig *preconfig, int argc, wchar_t * const * argv) |
| |
| Preinitialize Python from *preconfig* preconfiguration. |
| |
| Parse *argv* command line arguments (wide strings) if |
| :c:member:`~PyPreConfig.parse_argv` of *preconfig* is non-zero. |
| |
| *preconfig* must not be ``NULL``. |
| |
| The caller is responsible to handle exceptions (error or exit) using |
| :c:func:`PyStatus_Exception` and :c:func:`Py_ExitStatusException`. |
| |
| For :ref:`Python Configuration <init-python-config>` |
| (:c:func:`PyPreConfig_InitPythonConfig`), if Python is initialized with |
| command line arguments, the command line arguments must also be passed to |
| preinitialize Python, since they have an effect on the pre-configuration |
| like encodings. For example, the :option:`-X utf8 <-X>` command line option |
| enables the :ref:`Python UTF-8 Mode <utf8-mode>`. |
| |
| ``PyMem_SetAllocator()`` can be called after :c:func:`Py_PreInitialize` and |
| before :c:func:`Py_InitializeFromConfig` to install a custom memory allocator. |
| It can be called before :c:func:`Py_PreInitialize` if |
| :c:member:`PyPreConfig.allocator` is set to ``PYMEM_ALLOCATOR_NOT_SET``. |
| |
| Python memory allocation functions like :c:func:`PyMem_RawMalloc` must not be |
| used before the Python preinitialization, whereas calling directly ``malloc()`` |
| and ``free()`` is always safe. :c:func:`Py_DecodeLocale` must not be called |
| before the Python preinitialization. |
| |
| Example using the preinitialization to enable |
| the :ref:`Python UTF-8 Mode <utf8-mode>`:: |
| |
| PyStatus status; |
| PyPreConfig preconfig; |
| PyPreConfig_InitPythonConfig(&preconfig); |
| |
| preconfig.utf8_mode = 1; |
| |
| status = Py_PreInitialize(&preconfig); |
| if (PyStatus_Exception(status)) { |
| Py_ExitStatusException(status); |
| } |
| |
| /* at this point, Python speaks UTF-8 */ |
| |
| Py_Initialize(); |
| /* ... use Python API here ... */ |
| Py_Finalize(); |
| |
| |
| PyConfig |
| ======== |
| |
| .. c:type:: PyConfig |
| |
| Structure containing most parameters to configure Python. |
| |
| When done, the :c:func:`PyConfig_Clear` function must be used to release the |
| configuration memory. |
| |
| Structure methods: |
| |
| .. c:function:: void PyConfig_InitPythonConfig(PyConfig *config) |
| |
| Initialize configuration with the :ref:`Python Configuration |
| <init-python-config>`. |
| |
| .. c:function:: void PyConfig_InitIsolatedConfig(PyConfig *config) |
| |
| Initialize configuration with the :ref:`Isolated Configuration |
| <init-isolated-conf>`. |
| |
| .. c:function:: PyStatus PyConfig_SetString(PyConfig *config, wchar_t * const *config_str, const wchar_t *str) |
| |
| Copy the wide character string *str* into ``*config_str``. |
| |
| :ref:`Preinitialize Python <c-preinit>` if needed. |
| |
| .. c:function:: PyStatus PyConfig_SetBytesString(PyConfig *config, wchar_t * const *config_str, const char *str) |
| |
| Decode *str* using :c:func:`Py_DecodeLocale` and set the result into |
| ``*config_str``. |
| |
| :ref:`Preinitialize Python <c-preinit>` if needed. |
| |
| .. c:function:: PyStatus PyConfig_SetArgv(PyConfig *config, int argc, wchar_t * const *argv) |
| |
| Set command line arguments (:c:member:`~PyConfig.argv` member of |
| *config*) from the *argv* list of wide character strings. |
| |
| :ref:`Preinitialize Python <c-preinit>` if needed. |
| |
| .. c:function:: PyStatus PyConfig_SetBytesArgv(PyConfig *config, int argc, char * const *argv) |
| |
| Set command line arguments (:c:member:`~PyConfig.argv` member of |
| *config*) from the *argv* list of bytes strings. Decode bytes using |
| :c:func:`Py_DecodeLocale`. |
| |
| :ref:`Preinitialize Python <c-preinit>` if needed. |
| |
| .. c:function:: PyStatus PyConfig_SetWideStringList(PyConfig *config, PyWideStringList *list, Py_ssize_t length, wchar_t **items) |
| |
| Set the list of wide strings *list* to *length* and *items*. |
| |
| :ref:`Preinitialize Python <c-preinit>` if needed. |
| |
| .. c:function:: PyStatus PyConfig_Read(PyConfig *config) |
| |
| Read all Python configuration. |
| |
| Fields which are already initialized are left unchanged. |
| |
| The :c:func:`PyConfig_Read` function only parses |
| :c:member:`PyConfig.argv` arguments once: :c:member:`PyConfig.parse_argv` |
| is set to ``2`` after arguments are parsed. Since Python arguments are |
| strippped from :c:member:`PyConfig.argv`, parsing arguments twice would |
| parse the application options as Python options. |
| |
| :ref:`Preinitialize Python <c-preinit>` if needed. |
| |
| .. versionchanged:: 3.10 |
| The :c:member:`PyConfig.argv` arguments are now only parsed once, |
| :c:member:`PyConfig.parse_argv` is set to ``2`` after arguments are |
| parsed, and arguments are only parsed if |
| :c:member:`PyConfig.parse_argv` equals ``1``. |
| |
| .. c:function:: void PyConfig_Clear(PyConfig *config) |
| |
| Release configuration memory. |
| |
| Most ``PyConfig`` methods :ref:`preinitialize Python <c-preinit>` if needed. |
| In that case, the Python preinitialization configuration |
| (:c:type:`PyPreConfig`) in based on the :c:type:`PyConfig`. If configuration |
| fields which are in common with :c:type:`PyPreConfig` are tuned, they must |
| be set before calling a :c:type:`PyConfig` method: |
| |
| * :c:member:`PyConfig.dev_mode` |
| * :c:member:`PyConfig.isolated` |
| * :c:member:`PyConfig.parse_argv` |
| * :c:member:`PyConfig.use_environment` |
| |
| Moreover, if :c:func:`PyConfig_SetArgv` or :c:func:`PyConfig_SetBytesArgv` |
| is used, this method must be called before other methods, since the |
| preinitialization configuration depends on command line arguments (if |
| :c:member:`parse_argv` is non-zero). |
| |
| The caller of these methods is responsible to handle exceptions (error or |
| exit) using ``PyStatus_Exception()`` and ``Py_ExitStatusException()``. |
| |
| Structure fields: |
| |
| .. c:member:: PyWideStringList argv |
| |
| Command line arguments: :data:`sys.argv`. |
| |
| Set :c:member:`~PyConfig.parse_argv` to ``1`` to parse |
| :c:member:`~PyConfig.argv` the same way the regular Python parses Python |
| command line arguments and then to strip Python arguments from |
| :c:member:`~PyConfig.argv`. |
| |
| If :c:member:`~PyConfig.argv` is empty, an empty string is added to |
| ensure that :data:`sys.argv` always exists and is never empty. |
| |
| Default: ``NULL``. |
| |
| See also the :c:member:`~PyConfig.orig_argv` member. |
| |
| .. c:member:: wchar_t* base_exec_prefix |
| |
| :data:`sys.base_exec_prefix`. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` output. |
| |
| .. c:member:: wchar_t* base_executable |
| |
| Python base executable: :data:`sys._base_executable`. |
| |
| Set by the :envvar:`__PYVENV_LAUNCHER__` environment variable. |
| |
| Set from :c:member:`PyConfig.executable` if ``NULL``. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` output. |
| |
| .. c:member:: wchar_t* base_prefix |
| |
| :data:`sys.base_prefix`. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` output. |
| |
| .. c:member:: int buffered_stdio |
| |
| If equals to 0 and :c:member:`~PyConfig.configure_c_stdio` is non-zero, |
| disable buffering on the C streams stdout and stderr. |
| |
| Set to 0 by the :option:`-u` command line option and the |
| :envvar:`PYTHONUNBUFFERED` environment variable. |
| |
| stdin is always opened in buffered mode. |
| |
| Default: ``1``. |
| |
| .. c:member:: int bytes_warning |
| |
| If equals to 1, issue a warning when comparing :class:`bytes` or |
| :class:`bytearray` with :class:`str`, or comparing :class:`bytes` with |
| :class:`int`. |
| |
| If equal or greater to 2, raise a :exc:`BytesWarning` exception in these |
| cases. |
| |
| Incremented by the :option:`-b` command line option. |
| |
| Default: ``0``. |
| |
| .. c:member:: wchar_t* check_hash_pycs_mode |
| |
| Control the validation behavior of hash-based ``.pyc`` files: |
| value of the :option:`--check-hash-based-pycs` command line option. |
| |
| Valid values: |
| |
| - ``L"always"``: Hash the source file for invalidation regardless of |
| value of the 'check_source' flag. |
| - ``L"never"``: Assume that hash-based pycs always are valid. |
| - ``L"default"``: The 'check_source' flag in hash-based pycs |
| determines invalidation. |
| |
| Default: ``L"default"``. |
| |
| See also :pep:`552` "Deterministic pycs". |
| |
| .. c:member:: int configure_c_stdio |
| |
| If non-zero, configure C standard streams: |
| |
| * On Windows, set the binary mode (``O_BINARY``) on stdin, stdout and |
| stderr. |
| * If :c:member:`~PyConfig.buffered_stdio` equals zero, disable buffering |
| of stdin, stdout and stderr streams. |
| * If :c:member:`~PyConfig.interactive` is non-zero, enable stream |
| buffering on stdin and stdout (only stdout on Windows). |
| |
| Default: ``1`` in Python config, ``0`` in isolated config. |
| |
| .. c:member:: int dev_mode |
| |
| If non-zero, enable the :ref:`Python Development Mode <devmode>`. |
| |
| Default: ``-1`` in Python mode, ``0`` in isolated mode. |
| |
| .. c:member:: int dump_refs |
| |
| Dump Python refererences? |
| |
| If non-zero, dump all objects which are still alive at exit. |
| |
| Set to ``1`` by the :envvar:`PYTHONDUMPREFS` environment variable. |
| |
| Need a special build of Python with the ``Py_TRACE_REFS`` macro defined. |
| |
| Default: ``0``. |
| |
| .. c:member:: wchar_t* exec_prefix |
| |
| The site-specific directory prefix where the platform-dependent Python |
| files are installed: :data:`sys.exec_prefix`. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` output. |
| |
| .. c:member:: wchar_t* executable |
| |
| The absolute path of the executable binary for the Python interpreter: |
| :data:`sys.executable`. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` output. |
| |
| .. c:member:: int faulthandler |
| |
| Enable faulthandler? |
| |
| If non-zero, call :func:`faulthandler.enable` at startup. |
| |
| Set to ``1`` by :option:`-X faulthandler <-X>` and the |
| :envvar:`PYTHONFAULTHANDLER` environment variable. |
| |
| Default: ``-1`` in Python mode, ``0`` in isolated mode. |
| |
| .. c:member:: wchar_t* filesystem_encoding |
| |
| :term:`Filesystem encoding <filesystem encoding and error handler>`: |
| :func:`sys.getfilesystemencoding`. |
| |
| On macOS, Android and VxWorks: use ``"utf-8"`` by default. |
| |
| On Windows: use ``"utf-8"`` by default, or ``"mbcs"`` if |
| :c:member:`~PyPreConfig.legacy_windows_fs_encoding` of |
| :c:type:`PyPreConfig` is non-zero. |
| |
| Default encoding on other platforms: |
| |
| * ``"utf-8"`` if :c:member:`PyPreConfig.utf8_mode` is non-zero. |
| * ``"ascii"`` if Python detects that ``nl_langinfo(CODESET)`` announces |
| the ASCII encoding (or Roman8 encoding on HP-UX), whereas the |
| ``mbstowcs()`` function decodes from a different encoding (usually |
| Latin1). |
| * ``"utf-8"`` if ``nl_langinfo(CODESET)`` returns an empty string. |
| * Otherwise, use the :term:`locale encoding`: |
| ``nl_langinfo(CODESET)`` result. |
| |
| At Python statup, the encoding name is normalized to the Python codec |
| name. For example, ``"ANSI_X3.4-1968"`` is replaced with ``"ascii"``. |
| |
| See also the :c:member:`~PyConfig.filesystem_errors` member. |
| |
| .. c:member:: wchar_t* filesystem_errors |
| |
| :term:`Filesystem error handler <filesystem encoding and error handler>`: |
| :func:`sys.getfilesystemencodeerrors`. |
| |
| On Windows: use ``"surrogatepass"`` by default, or ``"replace"`` if |
| :c:member:`~PyPreConfig.legacy_windows_fs_encoding` of |
| :c:type:`PyPreConfig` is non-zero. |
| |
| On other platforms: use ``"surrogateescape"`` by default. |
| |
| Supported error handlers: |
| |
| * ``"strict"`` |
| * ``"surrogateescape"`` |
| * ``"surrogatepass"`` (only supported with the UTF-8 encoding) |
| |
| See also the :c:member:`~PyConfig.filesystem_encoding` member. |
| |
| .. c:member:: unsigned long hash_seed |
| .. c:member:: int use_hash_seed |
| |
| Randomized hash function seed. |
| |
| If :c:member:`~PyConfig.use_hash_seed` is zero, a seed is chosen randomly |
| at Python startup, and :c:member:`~PyConfig.hash_seed` is ignored. |
| |
| Set by the :envvar:`PYTHONHASHSEED` environment variable. |
| |
| Default *use_hash_seed* value: ``-1`` in Python mode, ``0`` in isolated |
| mode. |
| |
| .. c:member:: wchar_t* home |
| |
| Python home directory. |
| |
| If :c:func:`Py_SetPythonHome` has been called, use its argument if it is |
| not ``NULL``. |
| |
| Set by the :envvar:`PYTHONHOME` environment variable. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` input. |
| |
| .. c:member:: int import_time |
| |
| If non-zero, profile import time. |
| |
| Set the ``1`` by the :option:`-X importtime <-X>` option and the |
| :envvar:`PYTHONPROFILEIMPORTTIME` environment variable. |
| |
| Default: ``0``. |
| |
| .. c:member:: int inspect |
| |
| Enter interactive mode after executing a script or a command. |
| |
| If greater than 0, enable inspect: when a script is passed as first |
| argument or the -c option is used, enter interactive mode after executing |
| the script or the command, even when :data:`sys.stdin` does not appear to |
| be a terminal. |
| |
| Incremented by the :option:`-i` command line option. Set to ``1`` if the |
| :envvar:`PYTHONINSPECT` environment variable is non-empty. |
| |
| Default: ``0``. |
| |
| .. c:member:: int install_signal_handlers |
| |
| Install Python signal handlers? |
| |
| Default: ``1`` in Python mode, ``0`` in isolated mode. |
| |
| .. c:member:: int interactive |
| |
| If greater than 0, enable the interactive mode (REPL). |
| |
| Incremented by the :option:`-i` command line option. |
| |
| Default: ``0``. |
| |
| .. c:member:: int isolated |
| |
| If greater than 0, enable isolated mode: |
| |
| * :data:`sys.path` contains neither the script's directory (computed from |
| ``argv[0]`` or the current directory) nor the user's site-packages |
| directory. |
| * Python REPL doesn't import :mod:`readline` nor enable default readline |
| configuration on interactive prompts. |
| * Set :c:member:`~PyConfig.use_environment` and |
| :c:member:`~PyConfig.user_site_directory` to 0. |
| |
| Default: ``0`` in Python mode, ``1`` in isolated mode. |
| |
| See also :c:member:`PyPreConfig.isolated`. |
| |
| .. c:member:: int legacy_windows_stdio |
| |
| If non-zero, use :class:`io.FileIO` instead of |
| :class:`io.WindowsConsoleIO` for :data:`sys.stdin`, :data:`sys.stdout` |
| and :data:`sys.stderr`. |
| |
| Set to ``1`` if the :envvar:`PYTHONLEGACYWINDOWSSTDIO` environment |
| variable is set to a non-empty string. |
| |
| Only available on Windows. ``#ifdef MS_WINDOWS`` macro can be used for |
| Windows specific code. |
| |
| Default: ``0``. |
| |
| See also the :pep:`528` (Change Windows console encoding to UTF-8). |
| |
| .. c:member:: int malloc_stats |
| |
| If non-zero, dump statistics on :ref:`Python pymalloc memory allocator |
| <pymalloc>` at exit. |
| |
| Set to ``1`` by the :envvar:`PYTHONMALLOCSTATS` environment variable. |
| |
| The option is ignored if Python is built using ``--without-pymalloc``. |
| |
| Default: ``0``. |
| |
| .. c:member:: wchar_t* platlibdir |
| |
| Platform library directory name: :data:`sys.platlibdir`. |
| |
| Set by the :envvar:`PYTHONPLATLIBDIR` environment variable. |
| |
| Default: value of the ``PLATLIBDIR`` macro which is set at configure time |
| by ``--with-platlibdir`` (default: ``"lib"``). |
| |
| Part of the :ref:`Path Configuration <init-path-config>` input. |
| |
| .. versionadded:: 3.9 |
| |
| .. c:member:: wchar_t* pythonpath_env |
| |
| Module search paths (:data:`sys.path`) as a string separated by ``DELIM`` |
| (:data:`os.path.pathsep`). |
| |
| Set by the :envvar:`PYTHONPATH` environment variable. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` input. |
| |
| .. c:member:: PyWideStringList module_search_paths |
| .. c:member:: int module_search_paths_set |
| |
| Module search paths: :data:`sys.path`. |
| |
| If :c:member:`~PyConfig.module_search_paths_set` is equal to 0, the |
| function calculating the :ref:`Path Configuration <init-path-config>` |
| overrides the :c:member:`~PyConfig.module_search_paths` and sets |
| :c:member:`~PyConfig.module_search_paths_set` to ``1``. |
| |
| Default: empty list (``module_search_paths``) and ``0`` |
| (``module_search_paths_set``). |
| |
| Part of the :ref:`Path Configuration <init-path-config>` output. |
| |
| .. c:member:: int optimization_level |
| |
| Compilation optimization level: |
| |
| * ``0``: Peephole optimizer, set ``__debug__`` to ``True``. |
| * ``1``: Level 0, remove assertions, set ``__debug__`` to ``False``. |
| * ``2``: Level 1, strip docstrings. |
| |
| Incremented by the :option:`-O` command line option. Set to the |
| :envvar:`PYTHONOPTIMIZE` environment variable value. |
| |
| Default: ``0``. |
| |
| .. c:member:: PyWideStringList orig_argv |
| |
| The list of the original command line arguments passed to the Python |
| executable: :data:`sys.orig_argv`. |
| |
| If :c:member:`~PyConfig.orig_argv` list is empty and |
| :c:member:`~PyConfig.argv` is not a list only containing an empty |
| string, :c:func:`PyConfig_Read` copies :c:member:`~PyConfig.argv` into |
| :c:member:`~PyConfig.orig_argv` before modifying |
| :c:member:`~PyConfig.argv` (if :c:member:`~PyConfig.parse_argv` is |
| non-zero). |
| |
| See also the :c:member:`~PyConfig.argv` member and the |
| :c:func:`Py_GetArgcArgv` function. |
| |
| Default: empty list. |
| |
| .. versionadded:: 3.10 |
| |
| .. c:member:: int parse_argv |
| |
| Parse command line arguments? |
| |
| If equals to ``1``, parse :c:member:`~PyConfig.argv` the same way the regular |
| Python parses :ref:`command line arguments <using-on-cmdline>`, and strip |
| Python arguments from :c:member:`~PyConfig.argv`. |
| |
| The :c:func:`PyConfig_Read` function only parses |
| :c:member:`PyConfig.argv` arguments once: :c:member:`PyConfig.parse_argv` |
| is set to ``2`` after arguments are parsed. Since Python arguments are |
| strippped from :c:member:`PyConfig.argv`, parsing arguments twice would |
| parse the application options as Python options. |
| |
| Default: ``1`` in Python mode, ``0`` in isolated mode. |
| |
| .. versionchanged:: 3.10 |
| The :c:member:`PyConfig.argv` arguments are now only parsed if |
| :c:member:`PyConfig.parse_argv` equals to ``1``. |
| |
| .. c:member:: int parser_debug |
| |
| Parser debug mode. If greater than 0, turn on parser debugging output (for expert only, depending |
| on compilation options). |
| |
| Incremented by the :option:`-d` command line option. Set to the |
| :envvar:`PYTHONDEBUG` environment variable value. |
| |
| Default: ``0``. |
| |
| .. c:member:: int pathconfig_warnings |
| |
| On Unix, if non-zero, calculating the :ref:`Path Configuration |
| <init-path-config>` can log warnings into ``stderr``. If equals to 0, |
| suppress these warnings. |
| |
| It has no effect on Windows. |
| |
| Default: ``1`` in Python mode, ``0`` in isolated mode. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` input. |
| |
| .. c:member:: wchar_t* prefix |
| |
| The site-specific directory prefix where the platform independent Python |
| files are installed: :data:`sys.prefix`. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` output. |
| |
| .. c:member:: wchar_t* program_name |
| |
| Program name used to initialize :c:member:`~PyConfig.executable` and in |
| early error messages during Python initialization. |
| |
| * If :func:`Py_SetProgramName` has been called, use its argument. |
| * On macOS, use :envvar:`PYTHONEXECUTABLE` environment variable if set. |
| * If the ``WITH_NEXT_FRAMEWORK`` macro is defined, use |
| :envvar:`__PYVENV_LAUNCHER__` environment variable if set. |
| * Use ``argv[0]`` of :c:member:`~PyConfig.argv` if available and |
| non-empty. |
| * Otherwise, use ``L"python"`` on Windows, or ``L"python3"`` on other |
| platforms. |
| |
| Default: ``NULL``. |
| |
| Part of the :ref:`Path Configuration <init-path-config>` input. |
| |
| .. c:member:: wchar_t* pycache_prefix |
| |
| Directory where cached ``.pyc`` files are written: |
| :data:`sys.pycache_prefix`. |
| |
| Set by the :option:`-X pycache_prefix=PATH <-X>` command line option and |
| the :envvar:`PYTHONPYCACHEPREFIX` environment variable. |
| |
| If ``NULL``, :data:`sys.pycache_prefix` is set to ``None``. |
| |
| Default: ``NULL``. |
| |
| .. c:member:: int quiet |
| |
| Quiet mode. If greater than 0, don't display the copyright and version at |
| Python startup in interactive mode. |
| |
| Incremented by the :option:`-q` command line option. |
| |
| Default: ``0``. |
| |
| .. c:member:: wchar_t* run_command |
| |
| Value of the :option:`-c` command line option. |
| |
| Used by :c:func:`Py_RunMain`. |
| |
| Default: ``NULL``. |
| |
| .. c:member:: wchar_t* run_filename |
| |
| Filename passed on the command line: trailing command line argument |
| without :option:`-c` or :option:`-m`. |
| |
| For example, it is set to ``script.py`` by the ``python3 script.py arg`` |
| command. |
| |
| Used by :c:func:`Py_RunMain`. |
| |
| Default: ``NULL``. |
| |
| .. c:member:: wchar_t* run_module |
| |
| Value of the :option:`-m` command line option. |
| |
| Used by :c:func:`Py_RunMain`. |
| |
| Default: ``NULL``. |
| |
| .. c:member:: int show_ref_count |
| |
| Show total reference count at exit? |
| |
| Set to 1 by :option:`-X showrefcount <-X>` command line option. |
| |
| Need a debug build of Python (``Py_REF_DEBUG`` macro must be defined). |
| |
| Default: ``0``. |
| |
| .. c:member:: int site_import |
| |
| Import the :mod:`site` module at startup? |
| |
| If equal to zero, disable the import of the module site and the |
| site-dependent manipulations of :data:`sys.path` that it entails. |
| |
| Also disable these manipulations if the :mod:`site` module is explicitly |
| imported later (call :func:`site.main` if you want them to be triggered). |
| |
| Set to ``0`` by the :option:`-S` command line option. |
| |
| :data:`sys.flags.no_site` is set to the inverted value of |
| :c:member:`~PyConfig.site_import`. |
| |
| Default: ``1``. |
| |
| .. c:member:: int skip_source_first_line |
| |
| If non-zero, skip the first line of the :c:member:`PyConfig.run_filename` |
| source. |
| |
| It allows the usage of non-Unix forms of ``#!cmd``. This is intended for |
| a DOS specific hack only. |
| |
| Set to ``1`` by the :option:`-x` command line option. |
| |
| Default: ``0``. |
| |
| .. c:member:: wchar_t* stdio_encoding |
| .. c:member:: wchar_t* stdio_errors |
| |
| Encoding and encoding errors of :data:`sys.stdin`, :data:`sys.stdout` and |
| :data:`sys.stderr` (but :data:`sys.stderr` always uses |
| ``"backslashreplace"`` error handler). |
| |
| If :c:func:`Py_SetStandardStreamEncoding` has been called, use its |
| *error* and *errors* arguments if they are not ``NULL``. |
| |
| Use the :envvar:`PYTHONIOENCODING` environment variable if it is |
| non-empty. |
| |
| Default encoding: |
| |
| * ``"UTF-8"`` if :c:member:`PyPreConfig.utf8_mode` is non-zero. |
| * Otherwise, use the :term:`locale encoding`. |
| |
| Default error handler: |
| |
| * On Windows: use ``"surrogateescape"``. |
| * ``"surrogateescape"`` if :c:member:`PyPreConfig.utf8_mode` is non-zero, |
| or if the LC_CTYPE locale is "C" or "POSIX". |
| * ``"strict"`` otherwise. |
| |
| .. c:member:: int tracemalloc |
| |
| Enable tracemalloc? |
| |
| If non-zero, call :func:`tracemalloc.start` at startup. |
| |
| Set by :option:`-X tracemalloc=N <-X>` command line option and by the |
| :envvar:`PYTHONTRACEMALLOC` environment variable. |
| |
| Default: ``-1`` in Python mode, ``0`` in isolated mode. |
| |
| .. c:member:: int use_environment |
| |
| Use :ref:`environment variables <using-on-envvars>`? |
| |
| If equals to zero, ignore the :ref:`environment variables |
| <using-on-envvars>`. |
| |
| Default: ``1`` in Python config and ``0`` in isolated config. |
| |
| .. c:member:: int user_site_directory |
| |
| If non-zero, add the user site directory to :data:`sys.path`. |
| |
| Set to ``0`` by the :option:`-s` and :option:`-I` command line options. |
| |
| Set to ``0`` by the :envvar:`PYTHONNOUSERSITE` environment variable. |
| |
| Default: ``1`` in Python mode, ``0`` in isolated mode. |
| |
| .. c:member:: int verbose |
| |
| Verbose mode. If greater than 0, print a message each time a module is |
| imported, showing the place (filename or built-in module) from which |
| it is loaded. |
| |
| If greater or equal to 2, print a message for each file that is checked |
| for when searching for a module. Also provides information on module |
| cleanup at exit. |
| |
| Incremented by the :option:`-v` command line option. |
| |
| Set to the :envvar:`PYTHONVERBOSE` environment variable value. |
| |
| Default: ``0``. |
| |
| .. c:member:: PyWideStringList warnoptions |
| |
| Options of the :mod:`warnings` module to build warnings filters, lowest |
| to highest priority: :data:`sys.warnoptions`. |
| |
| The :mod:`warnings` module adds :data:`sys.warnoptions` in the reverse |
| order: the last :c:member:`PyConfig.warnoptions` item becomes the first |
| item of :data:`warnings.filters` which is checked first (highest |
| priority). |
| |
| Default: empty list. |
| |
| .. c:member:: int write_bytecode |
| |
| If equal to 0, Python won't try to write ``.pyc`` files on the import of |
| source modules. |
| |
| Set to ``0`` by the :option:`-B` command line option and the |
| :envvar:`PYTHONDONTWRITEBYTECODE` environment variable. |
| |
| :data:`sys.dont_write_bytecode` is initialized to the inverted value of |
| :c:member:`~PyConfig.write_bytecode`. |
| |
| Default: ``1``. |
| |
| .. c:member:: PyWideStringList xoptions |
| |
| Values of the :option:`-X` command line options: :data:`sys._xoptions`. |
| |
| Default: empty list. |
| |
| If :c:member:`~PyConfig.parse_argv` is non-zero, :c:member:`~PyConfig.argv` |
| arguments are parsed the same way the regular Python parses :ref:`command line |
| arguments <using-on-cmdline>`, and Python arguments are stripped from |
| :c:member:`~PyConfig.argv`. |
| |
| The :c:member:`~PyConfig.xoptions` options are parsed to set other options: see |
| the :option:`-X` command line option. |
| |
| .. versionchanged:: 3.9 |
| |
| The ``show_alloc_count`` field has been removed. |
| |
| |
| Initialization with PyConfig |
| ============================ |
| |
| Function to initialize Python: |
| |
| .. c:function:: PyStatus Py_InitializeFromConfig(const PyConfig *config) |
| |
| Initialize Python from *config* configuration. |
| |
| The caller is responsible to handle exceptions (error or exit) using |
| :c:func:`PyStatus_Exception` and :c:func:`Py_ExitStatusException`. |
| |
| If :c:func:`PyImport_FrozenModules`, :c:func:`PyImport_AppendInittab` or |
| :c:func:`PyImport_ExtendInittab` are used, they must be set or called after |
| Python preinitialization and before the Python initialization. |
| |
| The current configuration (``PyConfig`` type) is stored in |
| ``PyInterpreterState.config``. |
| |
| Example setting the program name:: |
| |
| void init_python(void) |
| { |
| PyStatus status; |
| |
| PyConfig config; |
| PyConfig_InitPythonConfig(&config); |
| |
| /* Set the program name. Implicitly preinitialize Python. */ |
| status = PyConfig_SetString(&config, &config.program_name, |
| L"/path/to/my_program"); |
| if (PyStatus_Exception(status)) { |
| goto exception; |
| } |
| |
| status = Py_InitializeFromConfig(&config); |
| if (PyStatus_Exception(status)) { |
| goto exception; |
| } |
| PyConfig_Clear(&config); |
| return; |
| |
| exception: |
| PyConfig_Clear(&config); |
| Py_ExitStatusException(status); |
| } |
| |
| More complete example modifying the default configuration, read the |
| configuration, and then override some parameters:: |
| |
| PyStatus init_python(const char *program_name) |
| { |
| PyStatus status; |
| |
| PyConfig config; |
| PyConfig_InitPythonConfig(&config); |
| |
| /* Set the program name before reading the configuration |
| (decode byte string from the locale encoding). |
| |
| Implicitly preinitialize Python. */ |
| status = PyConfig_SetBytesString(&config, &config.program_name, |
| program_name); |
| if (PyStatus_Exception(status)) { |
| goto done; |
| } |
| |
| /* Read all configuration at once */ |
| status = PyConfig_Read(&config); |
| if (PyStatus_Exception(status)) { |
| goto done; |
| } |
| |
| /* Append our custom search path to sys.path */ |
| status = PyWideStringList_Append(&config.module_search_paths, |
| L"/path/to/more/modules"); |
| if (PyStatus_Exception(status)) { |
| goto done; |
| } |
| |
| /* Override executable computed by PyConfig_Read() */ |
| status = PyConfig_SetString(&config, &config.executable, |
| L"/path/to/my_executable"); |
| if (PyStatus_Exception(status)) { |
| goto done; |
| } |
| |
| status = Py_InitializeFromConfig(&config); |
| |
| done: |
| PyConfig_Clear(&config); |
| return status; |
| } |
| |
| |
| .. _init-isolated-conf: |
| |
| Isolated Configuration |
| ====================== |
| |
| :c:func:`PyPreConfig_InitIsolatedConfig` and |
| :c:func:`PyConfig_InitIsolatedConfig` functions create a configuration to |
| isolate Python from the system. For example, to embed Python into an |
| application. |
| |
| This configuration ignores global configuration variables, environments |
| variables, command line arguments (:c:member:`PyConfig.argv` is not parsed) |
| and user site directory. The C standard streams (ex: ``stdout``) and the |
| LC_CTYPE locale are left unchanged. Signal handlers are not installed. |
| |
| Configuration files are still used with this configuration. Set the |
| :ref:`Path Configuration <init-path-config>` ("output fields") to ignore these |
| configuration files and avoid the function computing the default path |
| configuration. |
| |
| |
| .. _init-python-config: |
| |
| Python Configuration |
| ==================== |
| |
| :c:func:`PyPreConfig_InitPythonConfig` and :c:func:`PyConfig_InitPythonConfig` |
| functions create a configuration to build a customized Python which behaves as |
| the regular Python. |
| |
| Environments variables and command line arguments are used to configure |
| Python, whereas global configuration variables are ignored. |
| |
| This function enables C locale coercion (:pep:`538`) |
| and :ref:`Python UTF-8 Mode <utf8-mode>` |
| (:pep:`540`) depending on the LC_CTYPE locale, :envvar:`PYTHONUTF8` and |
| :envvar:`PYTHONCOERCECLOCALE` environment variables. |
| |
| |
| .. _init-path-config: |
| |
| Path Configuration |
| ================== |
| |
| :c:type:`PyConfig` contains multiple fields for the path configuration: |
| |
| * Path configuration inputs: |
| |
| * :c:member:`PyConfig.home` |
| * :c:member:`PyConfig.platlibdir` |
| * :c:member:`PyConfig.pathconfig_warnings` |
| * :c:member:`PyConfig.program_name` |
| * :c:member:`PyConfig.pythonpath_env` |
| * current working directory: to get absolute paths |
| * ``PATH`` environment variable to get the program full path |
| (from :c:member:`PyConfig.program_name`) |
| * ``__PYVENV_LAUNCHER__`` environment variable |
| * (Windows only) Application paths in the registry under |
| "Software\Python\PythonCore\X.Y\PythonPath" of HKEY_CURRENT_USER and |
| HKEY_LOCAL_MACHINE (where X.Y is the Python version). |
| |
| * Path configuration output fields: |
| |
| * :c:member:`PyConfig.base_exec_prefix` |
| * :c:member:`PyConfig.base_executable` |
| * :c:member:`PyConfig.base_prefix` |
| * :c:member:`PyConfig.exec_prefix` |
| * :c:member:`PyConfig.executable` |
| * :c:member:`PyConfig.module_search_paths_set`, |
| :c:member:`PyConfig.module_search_paths` |
| * :c:member:`PyConfig.prefix` |
| |
| If at least one "output field" is not set, Python calculates the path |
| configuration to fill unset fields. If |
| :c:member:`~PyConfig.module_search_paths_set` is equal to 0, |
| :c:member:`~PyConfig.module_search_paths` is overridden and |
| :c:member:`~PyConfig.module_search_paths_set` is set to 1. |
| |
| It is possible to completely ignore the function calculating the default |
| path configuration by setting explicitly all path configuration output |
| fields listed above. A string is considered as set even if it is non-empty. |
| ``module_search_paths`` is considered as set if |
| ``module_search_paths_set`` is set to 1. In this case, path |
| configuration input fields are ignored as well. |
| |
| Set :c:member:`~PyConfig.pathconfig_warnings` to 0 to suppress warnings when |
| calculating the path configuration (Unix only, Windows does not log any warning). |
| |
| If :c:member:`~PyConfig.base_prefix` or :c:member:`~PyConfig.base_exec_prefix` |
| fields are not set, they inherit their value from :c:member:`~PyConfig.prefix` |
| and :c:member:`~PyConfig.exec_prefix` respectively. |
| |
| :c:func:`Py_RunMain` and :c:func:`Py_Main` modify :data:`sys.path`: |
| |
| * If :c:member:`~PyConfig.run_filename` is set and is a directory which contains a |
| ``__main__.py`` script, prepend :c:member:`~PyConfig.run_filename` to |
| :data:`sys.path`. |
| * If :c:member:`~PyConfig.isolated` is zero: |
| |
| * If :c:member:`~PyConfig.run_module` is set, prepend the current directory |
| to :data:`sys.path`. Do nothing if the current directory cannot be read. |
| * If :c:member:`~PyConfig.run_filename` is set, prepend the directory of the |
| filename to :data:`sys.path`. |
| * Otherwise, prepend an empty string to :data:`sys.path`. |
| |
| If :c:member:`~PyConfig.site_import` is non-zero, :data:`sys.path` can be |
| modified by the :mod:`site` module. If |
| :c:member:`~PyConfig.user_site_directory` is non-zero and the user's |
| site-package directory exists, the :mod:`site` module appends the user's |
| site-package directory to :data:`sys.path`. |
| |
| The following configuration files are used by the path configuration: |
| |
| * ``pyvenv.cfg`` |
| * ``python._pth`` (Windows only) |
| * ``pybuilddir.txt`` (Unix only) |
| |
| The ``__PYVENV_LAUNCHER__`` environment variable is used to set |
| :c:member:`PyConfig.base_executable` |
| |
| |
| Py_RunMain() |
| ============ |
| |
| .. c:function:: int Py_RunMain(void) |
| |
| Execute the command (:c:member:`PyConfig.run_command`), the script |
| (:c:member:`PyConfig.run_filename`) or the module |
| (:c:member:`PyConfig.run_module`) specified on the command line or in the |
| configuration. |
| |
| By default and when if :option:`-i` option is used, run the REPL. |
| |
| Finally, finalizes Python and returns an exit status that can be passed to |
| the ``exit()`` function. |
| |
| See :ref:`Python Configuration <init-python-config>` for an example of |
| customized Python always running in isolated mode using |
| :c:func:`Py_RunMain`. |
| |
| |
| Py_GetArgcArgv() |
| ================ |
| |
| .. c:function:: void Py_GetArgcArgv(int *argc, wchar_t ***argv) |
| |
| Get the original command line arguments, before Python modified them. |
| |
| See also :c:member:`PyConfig.orig_argv` member. |
| |
| |
| Multi-Phase Initialization Private Provisional API |
| ================================================== |
| |
| This section is a private provisional API introducing multi-phase |
| initialization, the core feature of the :pep:`432`: |
| |
| * "Core" initialization phase, "bare minimum Python": |
| |
| * Builtin types; |
| * Builtin exceptions; |
| * Builtin and frozen modules; |
| * The :mod:`sys` module is only partially initialized |
| (ex: :data:`sys.path` doesn't exist yet). |
| |
| * "Main" initialization phase, Python is fully initialized: |
| |
| * Install and configure :mod:`importlib`; |
| * Apply the :ref:`Path Configuration <init-path-config>`; |
| * Install signal handlers; |
| * Finish :mod:`sys` module initialization (ex: create :data:`sys.stdout` |
| and :data:`sys.path`); |
| * Enable optional features like :mod:`faulthandler` and :mod:`tracemalloc`; |
| * Import the :mod:`site` module; |
| * etc. |
| |
| Private provisional API: |
| |
| * :c:member:`PyConfig._init_main`: if set to 0, |
| :c:func:`Py_InitializeFromConfig` stops at the "Core" initialization phase. |
| * :c:member:`PyConfig._isolated_interpreter`: if non-zero, |
| disallow threads, subprocesses and fork. |
| |
| .. c:function:: PyStatus _Py_InitializeMain(void) |
| |
| Move to the "Main" initialization phase, finish the Python initialization. |
| |
| No module is imported during the "Core" phase and the ``importlib`` module is |
| not configured: the :ref:`Path Configuration <init-path-config>` is only |
| applied during the "Main" phase. It may allow to customize Python in Python to |
| override or tune the :ref:`Path Configuration <init-path-config>`, maybe |
| install a custom :data:`sys.meta_path` importer or an import hook, etc. |
| |
| It may become possible to calculatin the :ref:`Path Configuration |
| <init-path-config>` in Python, after the Core phase and before the Main phase, |
| which is one of the :pep:`432` motivation. |
| |
| The "Core" phase is not properly defined: what should be and what should |
| not be available at this phase is not specified yet. The API is marked |
| as private and provisional: the API can be modified or even be removed |
| anytime until a proper public API is designed. |
| |
| Example running Python code between "Core" and "Main" initialization |
| phases:: |
| |
| void init_python(void) |
| { |
| PyStatus status; |
| |
| PyConfig config; |
| PyConfig_InitPythonConfig(&config); |
| config._init_main = 0; |
| |
| /* ... customize 'config' configuration ... */ |
| |
| status = Py_InitializeFromConfig(&config); |
| PyConfig_Clear(&config); |
| if (PyStatus_Exception(status)) { |
| Py_ExitStatusException(status); |
| } |
| |
| /* Use sys.stderr because sys.stdout is only created |
| by _Py_InitializeMain() */ |
| int res = PyRun_SimpleString( |
| "import sys; " |
| "print('Run Python code before _Py_InitializeMain', " |
| "file=sys.stderr)"); |
| if (res < 0) { |
| exit(1); |
| } |
| |
| /* ... put more configuration code here ... */ |
| |
| status = _Py_InitializeMain(); |
| if (PyStatus_Exception(status)) { |
| Py_ExitStatusException(status); |
| } |
| } |