# Python 初始化設定

## PyInitConfig C API

在 3.14 版被加入.

Python 可以使用 `Py_InitializeFromInitConfig()` 來初始化。

The `Py_RunMain()` function can be used to write a customized Python program.

See also Initialization, Finalization, and Threads.

也參考

PEP 741 "Python Configuration C API".

### 範例

Example of customized Python always running with the Python Development Mode enabled; return `-1` on error:

    int init_python(void)
    {
        PyInitConfig *config = PyInitConfig_Create();
        if (config == NULL) {
            printf("PYTHON INIT ERROR: memory allocation failed\n");
            return -1;
        }

        // Enable the Python Development Mode
        if (PyInitConfig_SetInt(config, "dev_mode", 1) < 0) {
            goto error;
        }

        // Initialize Python with the configuration
        if (Py_InitializeFromInitConfig(config) < 0) {
            goto error;
        }
        PyInitConfig_Free(config);
        return 0;

    error:
        {
            // Display the error message.
            //
            // This uncommon braces style is used, because you cannot make
            // goto targets point to variable declarations.
            const char *err_msg;
            (void)PyInitConfig_GetError(config, &err_msg);
            printf("PYTHON INIT ERROR: %s\n", err_msg);
            PyInitConfig_Free(config);
            return -1;
        }
    }

### 建立設定

struct PyInitConfig

  Opaque structure to configure the Python initialization.

PyInitConfig *PyInitConfig_Create(void)

  Create a new initialization configuration using Isolated Configuration default values.

  必須由 `PyInitConfig_Free()` 來釋放。

  在記憶體配置失敗時回傳 `NULL`。

void PyInitConfig_Free(PyInitConfig *config)

  釋放初始化配置 config 的記憶體。

  如果 config 是 `NULL`，則不執行任何操作。

### 錯誤處理

int PyInitConfig_GetError(PyInitConfig *config, const char **err_msg)

  取得 config 錯誤訊息。

  - 如果設定了錯誤，則設置 *err_msg 並回傳 `1`。

  - 如果沒有設定錯誤，則設定 *err_msg 為 `NULL` 並回傳 `0`。

  錯誤訊息是 UTF-8 編碼的字串。

  If config has an exit code, format the exit code as an error message.

  The error message remains valid until another `PyInitConfig` function is called with config. The caller doesn't have to free the error message.

int PyInitConfig_GetExitCode(PyInitConfig *config, int *exitcode)

  Get the config exit code.

  - Set *exitcode and return `1` if config has an exit code set.

  - Return `0` if config has no exit code set.

  Only the `Py_InitializeFromInitConfig()` function can set an exit code if the `parse_argv` option is non-zero.

  An exit code can be set when parsing the command line failed (exit code `2`) or when a command line option asks to display the command line help (exit code `0`).

### Get Options

The configuration option name parameter must be a non-NULL null-terminated UTF-8 encoded string. See Configuration Options.

int PyInitConfig_HasOption(PyInitConfig *config, const char *name)

  測試配置是否有名為 name 的選項。

  如果選項存在則回傳 `1`，否則回傳 `0`。

int PyInitConfig_GetInt(PyInitConfig *config, const char *name, int64_t *value)

  Get an integer configuration option.

  - Set *value, and return `0` on success.

  - Set an error in config and return `-1` on error.

int PyInitConfig_GetStr(PyInitConfig *config, const char *name, char **value)

  Get a string configuration option as a null-terminated UTF-8 encoded string.

  - Set *value, and return `0` on success.

  - Set an error in config and return `-1` on error.

  *value can be set to `NULL` if the option is an optional string and the option is unset.

  On success, the string must be released with `free(value)` if it's not `NULL`.

int PyInitConfig_GetStrList(PyInitConfig *config, const char *name, size_t *length, char ***items)

  Get a string list configuration option as an array of null-terminated UTF-8 encoded strings.

  - Set *length and *value, and return `0` on success.

  - Set an error in config and return `-1` on error.

  On success, the string list must be released with `PyInitConfig_FreeStrList(length, items)`.

void PyInitConfig_FreeStrList(size_t length, char **items)

  Free memory of a string list created by `PyInitConfig_GetStrList()`.

### Set Options

The configuration option name parameter must be a non-NULL null-terminated UTF-8 encoded string. See Configuration Options.

Some configuration options have side effects on other options. This logic is only implemented when `Py_InitializeFromInitConfig()` is called, not by the "Set" functions below. For example, setting `dev_mode` to `1` does not set `faulthandler` to `1`.

int PyInitConfig_SetInt(PyInitConfig *config, const char *name, int64_t value)

  Set an integer configuration option.

  - 成功時回傳 `0`。

  - Set an error in config and return `-1` on error.

int PyInitConfig_SetStr(PyInitConfig *config, const char *name, const char *value)

  Set a string configuration option from a null-terminated UTF-8 encoded string. The string is copied.

  - 成功時回傳 `0`。

  - Set an error in config and return `-1` on error.

int PyInitConfig_SetStrList(PyInitConfig *config, const char *name, size_t length, char *const *items)

  Set a string list configuration option from an array of null-terminated UTF-8 encoded strings. The string list is copied.

  - 成功時回傳 `0`。

  - Set an error in config and return `-1` on error.

### 模組

int PyInitConfig_AddModule(PyInitConfig *config, const char *name, PyObject *(*initfunc)(void))

  Add a built-in extension module to the table of built-in modules.

  The new module can be imported by the name name, and uses the function initfunc as the initialization function called on the first attempted import.

  - 成功時回傳 `0`。

  - Set an error in config and return `-1` on error.

  If Python is initialized multiple times, `PyInitConfig_AddModule()` must be called at each Python initialization.

  和 `PyImport_AppendInittab()` 函式類似。

### 初始化 Python

int Py_InitializeFromInitConfig(PyInitConfig *config)

  Initialize Python from the initialization configuration.

  - 成功時回傳 `0`。

  - Set an error in config and return `-1` on error.

  - Set an exit code in config and return `-1` if Python wants to exit.

  See `PyInitConfig_GetExitcode()` for the exit code case.

## Configuration Options

選項 | PyConfig/PyPreConfig 成員 | Type | Visibility
--- | --- | --- | ---
`"allocator"` | `allocator` | `int` | 唯讀
`"argv"` | `argv` | `list[str]` | 公開
`"base_exec_prefix"` | `base_exec_prefix` | `str` | 公開
`"base_executable"` | `base_executable` | `str` | 公開
`"base_prefix"` | `base_prefix` | `str` | 公開
`"buffered_stdio"` | `buffered_stdio` | `bool` | 唯讀
`"bytes_warning"` | `bytes_warning` | `int` | 公開
`"check_hash_pycs_mode"` | `check_hash_pycs_mode` | `str` | 唯讀
`"code_debug_ranges"` | `code_debug_ranges` | `bool` | 唯讀
`"coerce_c_locale"` | `coerce_c_locale` | `bool` | 唯讀
`"coerce_c_locale_warn"` | `coerce_c_locale_warn` | `bool` | 唯讀
`"configure_c_stdio"` | `configure_c_stdio` | `bool` | 唯讀
`"configure_locale"` | `configure_locale` | `bool` | 唯讀
`"cpu_count"` | `cpu_count` | `int` | 公開
`"dev_mode"` | `dev_mode` | `bool` | 唯讀
`"dump_refs"` | `dump_refs` | `bool` | 唯讀
`"dump_refs_file"` | `dump_refs_file` | `str` | 唯讀
`"exec_prefix"` | `exec_prefix` | `str` | 公開
`"executable"` | `executable` | `str` | 公開
`"faulthandler"` | `faulthandler` | `bool` | 唯讀
`"filesystem_encoding"` | `filesystem_encoding` | `str` | 唯讀
`"filesystem_errors"` | `filesystem_errors` | `str` | 唯讀
`"hash_seed"` | `hash_seed` | `int` | 唯讀
`"home"` | `home` | `str` | 唯讀
`"import_time"` | `import_time` | `int` | 唯讀
`"inspect"` | `inspect` | `bool` | 公開
`"install_signal_handlers"` | `install_signal_handlers` | `bool` | 唯讀
`"int_max_str_digits"` | `int_max_str_digits` | `int` | 公開
`"interactive"` | `interactive` | `bool` | 公開
`"isolated"` | `isolated` | `bool` | 唯讀
`"legacy_windows_fs_encoding"` | `legacy_windows_fs_encoding` | `bool` | 唯讀
`"legacy_windows_stdio"` | `legacy_windows_stdio` | `bool` | 唯讀
`"malloc_stats"` | `malloc_stats` | `bool` | 唯讀
`"module_search_paths"` | `module_search_paths` | `list[str]` | 公開
`"optimization_level"` | `optimization_level` | `int` | 公開
`"orig_argv"` | `orig_argv` | `list[str]` | 唯讀
`"parse_argv"` | `parse_argv` | `bool` | 唯讀
`"parser_debug"` | `parser_debug` | `bool` | 公開
`"pathconfig_warnings"` | `pathconfig_warnings` | `bool` | 唯讀
`"perf_profiling"` | `perf_profiling` | `bool` | 唯讀
`"platlibdir"` | `platlibdir` | `str` | 公開
`"prefix"` | `prefix` | `str` | 公開
`"surrogateescape"` | `program_name` | `str` | 唯讀
`"pycache_prefix"` | `pycache_prefix` | `str` | 公開
`"quiet"` | `quiet` | `bool` | 公開
`"run_command"` | `run_command` | `str` | 唯讀
`"run_filename"` | `run_filename` | `str` | 唯讀
`"run_module"` | `run_module` | `str` | 唯讀
`"run_presite"` | `run_presite` | `str` | 唯讀
`"safe_path"` | `safe_path` | `bool` | 唯讀
`"show_ref_count"` | `show_ref_count` | `bool` | 唯讀
`"site_import"` | `site_import` | `bool` | 唯讀
`"skip_source_first_line"` | `skip_source_first_line` | `bool` | 唯讀
`"stdio_encoding"` | `stdio_encoding` | `str` | 唯讀
`"stdio_errors"` | `stdio_errors` | `str` | 唯讀
`"stdlib_dir"` | `stdlib_dir` | `str` | 公開
`"tracemalloc"` | `tracemalloc` | `int` | 唯讀
`"use_environment"` | `use_environment` | `bool` | 公開
`"use_frozen_modules"` | `use_frozen_modules` | `bool` | 唯讀
`"use_hash_seed"` | `use_hash_seed` | `bool` | 唯讀
`"use_system_logger"` | `use_system_logger` | `bool` | 唯讀
`"user_site_directory"` | `user_site_directory` | `bool` | 唯讀
`"utf8_mode"` | `utf8_mode` | `bool` | 唯讀
`"verbose"` | `verbose` | `int` | 公開
`"warn_default_encoding"` | `warn_default_encoding` | `bool` | 唯讀
`"warnoptions"` | `warnoptions` | `list[str]` | 公開
`"write_bytecode"` | `write_bytecode` | `bool` | 公開
`"xoptions"` | `xoptions` | `dict[str, str]` | 公開
`"_pystats"` | `_pystats` | `bool` | 唯讀

Visibility:

- Public: Can by get by `PyConfig_Get()` and set by `PyConfig_Set()`.

- Read-only: Can by get by `PyConfig_Get()`, but cannot be set by `PyConfig_Set()`.

## Runtime Python configuration API

At runtime, it's possible to get and set configuration options using `PyConfig_Get()` and `PyConfig_Set()` functions.

The configuration option name parameter must be a non-NULL null-terminated UTF-8 encoded string. See Configuration Options.

Some options are read from the `sys` attributes. For example, the option `"argv"` is read from `sys.argv`.

PyObject *PyConfig_Get(const char *name)

  Get the current runtime value of a configuration option as a Python object.

  - Return a new reference on success.

  - Set an exception and return `NULL` on error.

  The object type depends on the configuration option. It can be:

  - `bool`

  - `int`

  - `str`

  - `list[str]`

  - `dict[str, str]`

  The caller must have an attached thread state. The function cannot be called before Python initialization nor after Python finalization.

  在 3.14 版被加入.

int PyConfig_GetInt(const char *name, int *value)

  Similar to `PyConfig_Get()`, but get the value as a C int.

  - 成功時回傳 `0`。

  - Set an exception and return `-1` on error.

  在 3.14 版被加入.

PyObject *PyConfig_Names(void)

  Get all configuration option names as a `frozenset`.

  - Return a new reference on success.

  - Set an exception and return `NULL` on error.

  The caller must have an attached thread state. The function cannot be called before Python initialization nor after Python finalization.

  在 3.14 版被加入.

int PyConfig_Set(const char *name, PyObject *value)

  Set the current runtime value of a configuration option.

  - 如果沒有選項 name，則引發 `ValueError`。

  - 如果 value 是無效值，則引發 `ValueError`。

  - 如果選項是唯讀的（無法設定），則引發 `ValueError`。

  - Raise a `TypeError` if value has not the proper type.

  The caller must have an attached thread state. The function cannot be called before Python initialization nor after Python finalization.

  Raises an auditing event `cpython.PyConfig_Set` with arguments `name`, `value`.

  在 3.14 版被加入.

## PyConfig C API

在 3.8 版被加入.

Python can be initialized with `Py_InitializeFromConfig()` and the `PyConfig` structure. It can be preinitialized with `Py_PreInitialize()` and the `PyPreConfig` structure.

There are two kinds of configuration:

- The Python Configuration can be used to build a customized Python which behaves as the regular Python. For example, environment variables and command line arguments are used to configure Python.

- The Isolated Configuration can be used to embed Python into an application. It isolates Python from the system. For example, environment variables are ignored, the LC_CTYPE locale is left unchanged and no signal handler is registered.

The `Py_RunMain()` function can be used to write a customized Python program.

See also Initialization, Finalization, and Threads.

也參考

PEP 587 "Python Initialization Configuration".

### 範例

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

type PyWideStringList

  `wchar_t*` 字串串列。

  If length is non-zero, items must be non-`NULL` and all strings must be non-`NULL`.

  方法：

  PyStatus PyWideStringList_Append(PyWideStringList *list, const wchar_t *item)

    Append item to list.

    Python must be preinitialized to call this 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:

  Py_ssize_t length

    串列長度。

  wchar_t **items

    List items.

### PyStatus

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:

  int exitcode

    Exit code. Argument passed to `exit()`.

  const char *err_msg

    錯誤訊息。

  const char *func

    Name of the function which created an error, can be `NULL`.

  建立狀態的函式：

  PyStatus PyStatus_Ok(void)

    成功。

  PyStatus PyStatus_Error(const char *err_msg)

    附帶訊息的初始化錯誤。

    err_msg 不可為 `NULL`。

  PyStatus PyStatus_NoMemory(void)

    Memory allocation failure (out of memory).

  PyStatus PyStatus_Exit(int exitcode)

    以指定的退出代號退出 Python。

  處理狀態的函式：

  int PyStatus_Exception(PyStatus status)

    Is the status an error or an exit? If true, the exception must be handled; by calling `Py_ExitStatusException()` for example.

  int PyStatus_IsError(PyStatus status)

    Is the result an error?

  int PyStatus_IsExit(PyStatus status)

    Is the result an exit?

  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.

備註

Internally, Python uses macros which set `PyStatus.func`, whereas functions to create a status set `func` to `NULL`.

範例：

    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

type PyPreConfig

  Structure used to preinitialize Python.

  Function to initialize a preconfiguration:

  void PyPreConfig_InitPythonConfig(PyPreConfig *preconfig)

    Initialize the preconfiguration with Python Configuration.

  void PyPreConfig_InitIsolatedConfig(PyPreConfig *preconfig)

    Initialize the preconfiguration with Isolated Configuration.

  Structure fields:

  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`): use `malloc()` of the C library.

    - `PYMEM_ALLOCATOR_MALLOC_DEBUG` (`4`): force usage of `malloc()` with debug hooks.

    - `PYMEM_ALLOCATOR_PYMALLOC` (`5`): Python pymalloc memory allocator.

    - `PYMEM_ALLOCATOR_PYMALLOC_DEBUG` (`6`): Python pymalloc memory allocator with debug hooks.

    - `PYMEM_ALLOCATOR_MIMALLOC` (`6`): use `mimalloc`, a fast malloc replacement.

    - `PYMEM_ALLOCATOR_MIMALLOC_DEBUG` (`7`): use `mimalloc`, a fast malloc replacement with debug hooks.

    `PYMEM_ALLOCATOR_PYMALLOC` and `PYMEM_ALLOCATOR_PYMALLOC_DEBUG` are not supported if Python is `configured using --without-pymalloc`.

    `PYMEM_ALLOCATOR_MIMALLOC` and `PYMEM_ALLOCATOR_MIMALLOC_DEBUG` are not supported if Python is `configured using --without-mimalloc` or if the underlying atomic support isn't available.

    請見記憶體管理。

    預設：`PYMEM_ALLOCATOR_NOT_SET`。

  int configure_locale

    Set the LC_CTYPE locale to the user preferred locale.

    If equals to `0`, set `coerce_c_locale` and `coerce_c_locale_warn` members to `0`.

    請見 locale encoding。

    Default: `1` in Python config, `0` in isolated config.

  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.

    請見 locale encoding。

    Default: `-1` in Python config, `0` in isolated config.

  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.

  int dev_mode

    Python Development Mode: see `PyConfig.dev_mode`.

    Default: `-1` in Python mode, `0` in isolated mode.

  int isolated

    Isolated mode: see `PyConfig.isolated`.

    Default: `0` in Python mode, `1` in isolated mode.

  int legacy_windows_fs_encoding

    如果不為 0：

    - 將 `PyPreConfig.utf8_mode` 設為 `0`、

    - 將 `PyConfig.filesystem_encoding` 設為 `"mbcs"`、

    - 將 `PyConfig.filesystem_errors` 設為 `"replace"`。

    Initialized from the `PYTHONLEGACYWINDOWSFSENCODING` environment variable value.

    Only available on Windows. `#ifdef MS_WINDOWS` macro can be used for Windows specific code.

    預設：`0`。

  int parse_argv

    If non-zero, `Py_PreInitializeFromArgs()` and `Py_PreInitializeFromBytesArgs()` parse their `argv` argument the same way the regular Python parses command line arguments: see Command Line Arguments.

    Default: `1` in Python config, `0` in isolated config.

  int use_environment

    Use environment variables? See `PyConfig.use_environment`.

    Default: `1` in Python config and `0` in isolated config.

  int utf8_mode

    If non-zero, enable the Python UTF-8 Mode.

    Set to `0` or `1` by the `-X utf8` command line option and the `PYTHONUTF8` environment variable.

    預設值：`1`。

### Preinitialize Python with PyPreConfig

The preinitialization of Python:

- Set the Python memory allocators (`PyPreConfig.allocator`)

- Configure the LC_CTYPE locale (locale encoding)

- Set the Python UTF-8 Mode (`PyPreConfig.utf8_mode`)

The current preconfiguration (`PyPreConfig` type) is stored in `_PyRuntime.preconfig`.

Functions to preinitialize Python:

PyStatus Py_PreInitialize(const PyPreConfig *preconfig)

  Preinitialize Python from preconfig preconfiguration.

  preconfig 不可為 `NULL`。

PyStatus Py_PreInitializeFromBytesArgs(const PyPreConfig *preconfig, int argc, char *const *argv)

  Preinitialize Python from preconfig preconfiguration.

  Parse argv command line arguments (bytes strings) if `parse_argv` of preconfig is non-zero.

  preconfig 不可為 `NULL`。

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 `parse_argv` of preconfig is non-zero.

  preconfig 不可為 `NULL`。

The caller is responsible to handle exceptions (error or exit) using `PyStatus_Exception()` and `Py_ExitStatusException()`.

For Python Configuration (`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 `-X utf8` command line option enables the Python UTF-8 Mode.

`PyMem_SetAllocator()` can be called after `Py_PreInitialize()` and before `Py_InitializeFromConfig()` to install a custom memory allocator. It can be called before `Py_PreInitialize()` if `PyPreConfig.allocator` is set to `PYMEM_ALLOCATOR_NOT_SET`.

Python memory allocation functions like `PyMem_RawMalloc()` must not be used before the Python preinitialization, whereas calling directly `malloc()` and `free()` is always safe. `Py_DecodeLocale()` must not be called before the Python preinitialization.

Example using the preinitialization to enable the Python UTF-8 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

type PyConfig

  Structure containing most parameters to configure Python.

  When done, the `PyConfig_Clear()` function must be used to release the configuration memory.

  Structure methods:

  void PyConfig_InitPythonConfig(PyConfig *config)

    Initialize configuration with the Python Configuration.

  void PyConfig_InitIsolatedConfig(PyConfig *config)

    Initialize configuration with the Isolated Configuration.

  PyStatus PyConfig_SetString(PyConfig *config, wchar_t *const *config_str, const wchar_t *str)

    Copy the wide character string str into `*config_str`.

    Preinitialize Python if needed.

  PyStatus PyConfig_SetBytesString(PyConfig *config, wchar_t *const *config_str, const char *str)

    Decode str using `Py_DecodeLocale()` and set the result into `*config_str`.

    Preinitialize Python if needed.

  PyStatus PyConfig_SetArgv(PyConfig *config, int argc, wchar_t *const *argv)

    Set command line arguments (`argv` member of config) from the argv list of wide character strings.

    Preinitialize Python if needed.

  PyStatus PyConfig_SetBytesArgv(PyConfig *config, int argc, char *const *argv)

    Set command line arguments (`argv` member of config) from the argv list of bytes strings. Decode bytes using `Py_DecodeLocale()`.

    Preinitialize Python if needed.

  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.

    Preinitialize Python if needed.

  PyStatus PyConfig_Read(PyConfig *config)

    讀取所有 Python 配置。

    已經初始化的欄位將保持不變。

    Fields for path configuration are no longer calculated or modified when calling this function, as of Python 3.11.

    The `PyConfig_Read()` function only parses `PyConfig.argv` arguments once: `PyConfig.parse_argv` is set to `2` after arguments are parsed. Since Python arguments are stripped from `PyConfig.argv`, parsing arguments twice would parse the application options as Python options.

    Preinitialize Python if needed.

    在 3.10 版的變更: The `PyConfig.argv` arguments are now only parsed once, `PyConfig.parse_argv` is set to `2` after arguments are parsed, and arguments are only parsed if `PyConfig.parse_argv` equals `1`.

    在 3.11 版的變更: `PyConfig_Read()` no longer calculates all paths, and so fields listed under Python Path Configuration may no longer be updated until `Py_InitializeFromConfig()` is called.

  void PyConfig_Clear(PyConfig *config)

    Release configuration memory.

  Most `PyConfig` methods preinitialize Python if needed. In that case, the Python preinitialization configuration (`PyPreConfig`) in based on the `PyConfig`. If configuration fields which are in common with `PyPreConfig` are tuned, they must be set before calling a `PyConfig` method:

  - `PyConfig.dev_mode`

  - `PyConfig.isolated`

  - `PyConfig.parse_argv`

  - `PyConfig.use_environment`

  Moreover, if `PyConfig_SetArgv()` or `PyConfig_SetBytesArgv()` is used, this method must be called before other methods, since the preinitialization configuration depends on command line arguments (if `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:

  PyWideStringList argv

    Set `sys.argv` command line arguments based on `argv`. These parameters are similar to those passed to the program's `main()` function with the difference that the first entry should refer to the script file to be executed rather than the executable hosting the Python interpreter. If there isn't a script that will be run, the first entry in `argv` can be an empty string.

    Set `parse_argv` to `1` to parse `argv` the same way the regular Python parses Python command line arguments and then to strip Python arguments from `argv`.

    If `argv` is empty, an empty string is added to ensure that `sys.argv` always exists and is never empty.

    預設值：`NULL`。

    另請參閱 `orig_argv` 成員。

  int safe_path

    If equals to zero, `Py_RunMain()` prepends a potentially unsafe path to `sys.path` at startup:

    - If `argv[0]` is equal to `L"-m"` (`python -m module`), prepend the current working directory.

    - If running a script (`python script.py`), prepend the script's directory. If it's a symbolic link, resolve symbolic links.

    - Otherwise (`python -c code` and `python`), prepend an empty string, which means the current working directory.

    Set to `1` by the `-P` command line option and the `PYTHONSAFEPATH` environment variable.

    Default: `0` in Python config, `1` in isolated config.

    在 3.11 版被加入.

  wchar_t *base_exec_prefix

    `sys.base_exec_prefix`。

    預設值：`NULL`。

    Part of the Python Path Configuration output.

    也請見 `PyConfig.exec_prefix`

  wchar_t *base_executable

    Python base executable: `sys._base_executable`.

    由 `__PYVENV_LAUNCHER__` 環境變數設定。

    如果為 `NULL`，則從 `PyConfig.executable` 設定。

    預設值：`NULL`。

    Part of the Python Path Configuration output.

    也請見 `PyConfig.executable`

  wchar_t *base_prefix

    `sys.base_prefix`。

    預設值：`NULL`。

    Part of the Python Path Configuration output.

    也請見 `PyConfig.prefix`

  int buffered_stdio

    If equals to `0` and `configure_c_stdio` is non-zero, disable buffering on the C streams stdout and stderr.

    Set to `0` by the `-u` command line option and the `PYTHONUNBUFFERED` environment variable.

    stdin is always opened in buffered mode.

    預設值：`1`。

  int bytes_warning

    If equals to `1`, issue a warning when comparing `bytes` or `bytearray` with `str`, or comparing `bytes` with `int`.

    If equal or greater to `2`, raise a `BytesWarning` exception in these cases.

    Incremented by the `-b` command line option.

    預設：`0`。

    自從版本 3.15 後不推薦使用，將會自版本 3.17 中移除。: The `-b` and `-bb` options will become no-op in 3.17. `bytes_warning` member will be removed in 3.17.

  int warn_default_encoding

    If non-zero, emit a `EncodingWarning` warning when `io.TextIOWrapper` uses its default encoding. See 選擇性加入的編碼警告 for details.

    預設：`0`。

    在 3.10 版被加入.

  int code_debug_ranges

    If equals to `0`, disables the inclusion of the end line and column mappings in code objects. Also disables traceback printing carets to specific error locations.

    Set to `0` by the `PYTHONNODEBUGRANGES` environment variable and by the `-X no_debug_ranges` command line option.

    預設值：`1`。

    在 3.11 版被加入.

  wchar_t *check_hash_pycs_mode

    Control the validation behavior of hash-based `.pyc` files: value of the `--check-hash-based-pycs` command line option.

    有效值：

    - `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.

    預設：`L"default"`。

    See also PEP 552 "Deterministic pycs".

  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 `buffered_stdio` equals zero, disable buffering of stdin, stdout and stderr streams.

    - If `interactive` is non-zero, enable stream buffering on stdin and stdout (only stdout on Windows).

    Default: `1` in Python config, `0` in isolated config.

  int dev_mode

    If non-zero, enable the Python Development Mode.

    Set to `1` by the `-X dev` option and the `PYTHONDEVMODE` environment variable.

    Default: `-1` in Python mode, `0` in isolated mode.

  int dump_refs

    Dump Python references?

    If non-zero, dump all objects which are still alive at exit.

    Set to `1` by the `PYTHONDUMPREFS` environment variable.

    Needs a special build of Python with the `Py_TRACE_REFS` macro defined: see the `configure --with-trace-refs option`.

    預設：`0`。

  wchar_t *dump_refs_file

    Filename where to dump Python references.

    由 `PYTHONDUMPREFSFILE` 環境變數設定。

    預設值：`NULL`。

    在 3.11 版被加入.

  wchar_t *exec_prefix

    The site-specific directory prefix where the platform-dependent Python files are installed: `sys.exec_prefix`.

    預設值：`NULL`。

    Part of the Python Path Configuration output.

    也請見 `PyConfig.base_exec_prefix`

  wchar_t *executable

    The absolute path of the executable binary for the Python interpreter: `sys.executable`.

    預設值：`NULL`。

    Part of the Python Path Configuration output.

    也請見 `PyConfig.base_executable`

  int faulthandler

    啟用 faulthandler？

    如果非零，則在啟動時呼叫 `faulthandler.enable()`。

    Set to `1` by `-X faulthandler` and the `PYTHONFAULTHANDLER` environment variable.

    Default: `-1` in Python mode, `0` in isolated mode.

  wchar_t *filesystem_encoding

    Filesystem encoding: `sys.getfilesystemencoding()`.

    On macOS, Android and VxWorks: use `"utf-8"` by default.

    On Windows: use `"utf-8"` by default, or `"mbcs"` if `legacy_windows_fs_encoding` of `PyPreConfig` is non-zero.

    其他平台的預設編碼：

    - 如果 `PyPreConfig.utf8_mode` 非零，則為 `"utf-8"`。

    - `"ascii"` if Python detects that `nl_langinfo(CODESET)` announces the ASCII encoding, whereas the `mbstowcs()` function decodes from a different encoding (usually Latin1).

    - `"utf-8"` if `nl_langinfo(CODESET)` returns an empty string.

    - Otherwise, use the locale encoding: `nl_langinfo(CODESET)` result.

    At Python startup, the encoding name is normalized to the Python codec name. For example, `"ANSI_X3.4-1968"` is replaced with `"ascii"`.

    另請參閱 `filesystem_errors` 成員。

  wchar_t *filesystem_errors

    Filesystem error handler: `sys.getfilesystemencodeerrors()`.

    On Windows: use `"surrogatepass"` by default, or `"replace"` if `legacy_windows_fs_encoding` of `PyPreConfig` is non-zero.

    其他平台：預設使用 `"surrogateescape"`。

    支援的錯誤處理器：

    - `"strict"`

    - `"surrogateescape"`

    - `"surrogatepass"`（僅支援 UTF-8 編碼）

    另請參閱 `filesystem_encoding` 成員。

  int use_frozen_modules

    如果非零，則使用凍結模組。

    由 `PYTHON_FROZEN_MODULES` 環境變數設定。

    Default: `1` in a release build, or `0` in a debug build.

  unsigned long hash_seed
  int use_hash_seed

    Randomized hash function seed.

    If `use_hash_seed` is zero, a seed is chosen randomly at Python startup, and `hash_seed` is ignored.

    由 `PYTHONHASHSEED` 環境變數設定。

    Default use_hash_seed value: `-1` in Python mode, `0` in isolated mode.

  wchar_t *home

    Set the default Python "home" directory, that is, the location of the standard Python libraries (see `PYTHONHOME`).

    由 `PYTHONHOME` 環境變數設定。

    預設值：`NULL`。

    Part of the Python Path Configuration input.

  int import_time

    > If `1`, profile import time. If `2`, include additional output that indicates when an imported module has already been loaded.

    > 由 `-X importtime` 選項與 `PYTHONPROFILEIMPORTTIME` 環境變數設定。

    > 預設：`0`。

    在 3.14 版的變更: 新增對 `import_time = 2` 的支援

  int inspect

    在執行腳本或命令後進入互動模式。

    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 `sys.stdin` does not appear to be a terminal.

    Incremented by the `-i` command line option. Set to `1` if the `PYTHONINSPECT` environment variable is non-empty.

    預設：`0`。

  int install_signal_handlers

    Install Python signal handlers?

    Default: `1` in Python mode, `0` in isolated mode.

  int interactive

    If greater than `0`, enable the interactive mode (REPL).

    Incremented by the `-i` command line option.

    預設：`0`。

  int int_max_str_digits

    Configures the integer string conversion length limitation. An initial value of `-1` means the value will be taken from the command line or environment or otherwise default to 4300 (`sys.int_info.default_max_str_digits`). A value of `0` disables the limitation. Values greater than zero but less than 640 (`sys.int_info.str_digits_check_threshold`) are unsupported and will produce an error.

    Configured by the `-X int_max_str_digits` command line flag or the `PYTHONINTMAXSTRDIGITS` environment variable.

    Default: `-1` in Python mode. 4300 (`sys.int_info.default_max_str_digits`) in isolated mode.

    在 3.12 版被加入.

  int cpu_count

    If the value of `cpu_count` is not `-1` then it will override the return values of `os.cpu_count()`, `os.process_cpu_count()`, and `multiprocessing.cpu_count()`.

    Configured by the `-X cpu_count=n|default` command line flag or the `PYTHON_CPU_COUNT` environment variable.

    預設值：`1`。

    在 3.13 版被加入.

  int isolated

    If greater than `0`, enable isolated mode:

    - Set `safe_path` to `1`: don't prepend a potentially unsafe path to `sys.path` at Python startup, such as the current directory, the script's directory or an empty string.

    - 將 `use_environment` 設定為 `0`：忽略 `PYTHON` 環境變數。

    - Set `user_site_directory` to `0`: don't add the user site directory to `sys.path`.

    - Python REPL doesn't import `readline` nor enable default readline configuration on interactive prompts.

    Set to `1` by the `-I` command line option.

    Default: `0` in Python mode, `1` in isolated mode.

    See also the Isolated Configuration and `PyPreConfig.isolated`.

  int legacy_windows_stdio

    If non-zero, use `io.FileIO` instead of `io._WindowsConsoleIO` for `sys.stdin`, `sys.stdout` and `sys.stderr`.

    Set to `1` if the `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.

    預設：`0`。

    See also the PEP 528 (Change Windows console encoding to UTF-8).

  int malloc_stats

    If non-zero, dump statistics on Python pymalloc memory allocator at exit.

    Set to `1` by the `PYTHONMALLOCSTATS` environment variable.

    The option is ignored if Python is `configured using the --without-pymalloc option`.

    預設：`0`。

  wchar_t *platlibdir

    Platform library directory name: `sys.platlibdir`.

    Set by the `PYTHONPLATLIBDIR` environment variable.

    Default: value of the `PLATLIBDIR` macro which is set by the `configure --with-platlibdir option` (default: `"lib"`, or `"DLLs"` on Windows).

    Part of the Python Path Configuration input.

    在 3.9 版被加入.

    在 3.11 版的變更: This macro is now used on Windows to locate the standard library extension modules, typically under `DLLs`. However, for compatibility, note that this value is ignored for any non-standard layouts, including in-tree builds and virtual environments.

  wchar_t *pythonpath_env

    Module search paths (`sys.path`) as a string separated by `DELIM` (`os.pathsep`).

    Set by the `PYTHONPATH` environment variable.

    預設值：`NULL`。

    Part of the Python Path Configuration input.

  PyWideStringList module_search_paths
  int module_search_paths_set

    Module search paths: `sys.path`.

    If `module_search_paths_set` is equal to `0`, `Py_InitializeFromConfig()` will replace `module_search_paths` and sets `module_search_paths_set` to `1`.

    Default: empty list (`module_search_paths`) and `0` (`module_search_paths_set`).

    Part of the Python Path Configuration output.

  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 `-O` command line option. Set to the `PYTHONOPTIMIZE` environment variable value.

    預設：`0`。

  PyWideStringList orig_argv

    The list of the original command line arguments passed to the Python executable: `sys.orig_argv`.

    If `orig_argv` list is empty and `argv` is not a list only containing an empty string, `PyConfig_Read()` copies `argv` into `orig_argv` before modifying `argv` (if `parse_argv` is non-zero).

    See also the `argv` member and the `Py_GetArgcArgv()` function.

    Default: empty list.

    在 3.10 版被加入.

  int parse_argv

    Parse command line arguments?

    If equals to `1`, parse `argv` the same way the regular Python parses command line arguments, and strip Python arguments from `argv`.

    The `PyConfig_Read()` function only parses `PyConfig.argv` arguments once: `PyConfig.parse_argv` is set to `2` after arguments are parsed. Since Python arguments are stripped from `PyConfig.argv`, parsing arguments twice would parse the application options as Python options.

    Default: `1` in Python mode, `0` in isolated mode.

    在 3.10 版的變更: The `PyConfig.argv` arguments are now only parsed if `PyConfig.parse_argv` equals to `1`.

  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 `-d` command line option. Set to the `PYTHONDEBUG` environment variable value.

    Needs a debug build of Python (the `Py_DEBUG` macro must be defined).

    預設：`0`。

  int pathconfig_warnings

    If non-zero, calculation of path configuration is allowed to log warnings into `stderr`. If equals to `0`, suppress these warnings.

    Default: `1` in Python mode, `0` in isolated mode.

    Part of the Python Path Configuration input.

    在 3.11 版的變更: 現在也適用於 Windows。

  wchar_t *prefix

    The site-specific directory prefix where the platform independent Python files are installed: `sys.prefix`.

    預設值：`NULL`。

    Part of the Python Path Configuration output.

    也請見 `PyConfig.base_prefix`

  wchar_t *program_name

    Program name used to initialize `executable` and in early error messages during Python initialization.

    - On macOS, use `PYTHONEXECUTABLE` environment variable if set.

    - If the `WITH_NEXT_FRAMEWORK` macro is defined, use `__PYVENV_LAUNCHER__` environment variable if set.

    - Use `argv[0]` of `argv` if available and non-empty.

    - Otherwise, use `L"python"` on Windows, or `L"python3"` on other platforms.

    預設值：`NULL`。

    Part of the Python Path Configuration input.

  wchar_t *pycache_prefix

    Directory where cached `.pyc` files are written: `sys.pycache_prefix`.

    Set by the `-X pycache_prefix=PATH` command line option and the `PYTHONPYCACHEPREFIX` environment variable. The command-line option takes precedence.

    If `NULL`, `sys.pycache_prefix` is set to `None`.

    預設值：`NULL`。

  int quiet

    Quiet mode. If greater than `0`, don't display the copyright and version at Python startup in interactive mode.

    Incremented by the `-q` command line option.

    預設：`0`。

  wchar_t *run_command

    Value of the `-c` command line option.

    被 `Py_RunMain()` 使用。

    預設值：`NULL`。

  wchar_t *run_filename

    Filename passed on the command line: trailing command line argument without `-c` or `-m`. It is used by the `Py_RunMain()` function.

    For example, it is set to `script.py` by the `python3 script.py arg` command line.

    也請見 `PyConfig.skip_source_first_line` 選項。

    預設值：`NULL`。

  wchar_t *run_module

    Value of the `-m` command line option.

    被 `Py_RunMain()` 使用。

    預設值：`NULL`。

  wchar_t *run_presite

    `package.module` path to module that should be imported before `site.py` is run.

    Set by the `-X presite=package.module` command-line option and the `PYTHON_PRESITE` environment variable. The command-line option takes precedence.

    Needs a debug build of Python (the `Py_DEBUG` macro must be defined).

    預設值：`NULL`。

  int show_ref_count

    Show total reference count at exit (excluding immortal objects)?

    Set to `1` by `-X showrefcount` command line option.

    Needs a debug build of Python (the `Py_REF_DEBUG` macro must be defined).

    預設：`0`。

  int site_import

    Import the `site` module at startup?

    If equal to zero, disable the import of the module site and the site-dependent manipulations of `sys.path` that it entails.

    Also disable these manipulations if the `site` module is explicitly imported later (call `site.main()` if you want them to be triggered).

    Set to `0` by the `-S` command line option.

    `sys.flags.no_site` is set to the inverted value of `site_import`.

    預設值：`1`。

  int skip_source_first_line

    If non-zero, skip the first line of the `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 `-x` command line option.

    預設：`0`。

  wchar_t *stdio_encoding
  wchar_t *stdio_errors

    Encoding and encoding errors of `sys.stdin`, `sys.stdout` and `sys.stderr` (but `sys.stderr` always uses `"backslashreplace"` error handler).

    Use the `PYTHONIOENCODING` environment variable if it is non-empty.

    預設編碼：

    - 如果 `PyPreConfig.utf8_mode` 非零，則為 `"UTF-8"`。

    - 否則使用 locale encoding。

    Default error handler:

    - 在 Windows 上：使用 `"surrogateescape"`。

    - `"surrogateescape"` if `PyPreConfig.utf8_mode` is non-zero, or if the LC_CTYPE locale is "C" or "POSIX".

    - `"strict"` otherwise.

    也請見 `PyConfig.legacy_windows_stdio`。

  int tracemalloc

    Enable tracemalloc?

    If non-zero, call `tracemalloc.start()` at startup.

    Set by `-X tracemalloc=N` command line option and by the `PYTHONTRACEMALLOC` environment variable.

    Default: `-1` in Python mode, `0` in isolated mode.

  int perf_profiling

    要啟用 Linux `perf` 分析器支援嗎？

    如果等於 `1`，則啟用對 Linux `perf` 分析器的支援。

    如果等於 `2`，則啟用有 DWARF JIT 支援的 Linux `perf` 分析器的支援。

    Set to `1` by `-X perf` command-line option and the `PYTHONPERFSUPPORT` environment variable.

    Set to `2` by the `-X perf_jit` command-line option and the `PYTHON_PERF_JIT_SUPPORT` environment variable.

    預設值：`1`。

    也參考

    更多資訊請參見 Python support for the perf map compatible profilers。

    在 3.12 版被加入.

  wchar_t *stdlib_dir

    Directory of the Python standard library.

    預設值：`NULL`。

    在 3.11 版被加入.

  int use_environment

    Use environment variables?

    If equals to zero, ignore the environment variables.

    Set to `0` by the `-E` environment variable.

    Default: `1` in Python config and `0` in isolated config.

  int use_system_logger

    If non-zero, `stdout` and `stderr` will be redirected to the system log.

    Only available on macOS 10.12 and later, and on iOS.

    Default: `0` (don't use the system log) on macOS; `1` on iOS (use the system log).

    在 3.14 版被加入.

  int user_site_directory

    If non-zero, add the user site directory to `sys.path`.

    Set to `0` by the `-s` and `-I` command line options.

    Set to `0` by the `PYTHONNOUSERSITE` environment variable.

    Default: `1` in Python mode, `0` in isolated mode.

  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 than 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 `-v` command line option.

    Set by the `PYTHONVERBOSE` environment variable value.

    預設：`0`。

  PyWideStringList warnoptions

    Options of the `warnings` module to build warnings filters, lowest to highest priority: `sys.warnoptions`.

    The `warnings` module adds `sys.warnoptions` in the reverse order: the last `PyConfig.warnoptions` item becomes the first item of `warnings.filters` which is checked first (highest priority).

    The `-W` command line options adds its value to `warnoptions`, it can be used multiple times.

    The `PYTHONWARNINGS` environment variable can also be used to add warning options. Multiple options can be specified, separated by commas (`,`).

    Default: empty list.

  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 `-B` command line option and the `PYTHONDONTWRITEBYTECODE` environment variable.

    `sys.dont_write_bytecode` is initialized to the inverted value of `write_bytecode`.

    預設值：`1`。

  PyWideStringList xoptions

    Values of the `-X` command line options: `sys._xoptions`.

    Default: empty list.

  int _pystats

    If non-zero, write performance statistics at Python exit.

    Need a special build with the `Py_STATS` macro: see `--enable-pystats`.

    預設：`0`。

If `parse_argv` is non-zero, `argv` arguments are parsed the same way the regular Python parses command line arguments, and Python arguments are stripped from `argv`.

The `xoptions` options are parsed to set other options: see the `-X` command line option.

在 3.9 版的變更: The `show_alloc_count` field has been removed.

### Initialization with PyConfig

Initializing the interpreter from a populated configuration struct is handled by calling `Py_InitializeFromConfig()`.

The caller is responsible to handle exceptions (error or exit) using `PyStatus_Exception()` and `Py_ExitStatusException()`.

If `PyImport_FrozenModules()`, `PyImport_AppendInittab()` or `PyImport_ExtendInittab()` are used, they must be set or called after Python preinitialization and before the Python initialization. If Python is initialized multiple times, `PyImport_AppendInittab()` or `PyImport_ExtendInittab()` must be called before each 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. Note that since 3.11, many parameters are not calculated until initialization, and so values cannot be read from the configuration structure. Any values set before initialize is called will be left unchanged by initialization:

    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;
        }

        /* Specify sys.path explicitly */
        /* If you want to modify the default set of paths, finish
           initialization first and then use PySys_GetAttrString("path") */
        config.module_search_paths_set = 1;
        status = PyWideStringList_Append(&config.module_search_paths,
                                         L"/path/to/stdlib");
        if (PyStatus_Exception(status)) {
            goto done;
        }
        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;
    }

### Isolated Configuration

`PyPreConfig_InitIsolatedConfig()` and `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, environment variables, command line arguments (`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 to determine paths that are unspecified. Ensure `PyConfig.home` is specified to avoid computing the default path configuration.

### Python Configuration

`PyPreConfig_InitPythonConfig()` and `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 Python UTF-8 Mode (PEP 540) depending on the LC_CTYPE locale, `PYTHONUTF8` and `PYTHONCOERCECLOCALE` environment variables.

### Python 路徑配置

`PyConfig` contains multiple fields for the path configuration:

- Path configuration inputs:

  - `PyConfig.home`

  - `PyConfig.platlibdir`

  - `PyConfig.pathconfig_warnings`

  - `PyConfig.program_name`

  - `PyConfig.pythonpath_env`

  - current working directory: to get absolute paths

  - `PATH` environment variable to get the program full path (from `PyConfig.program_name`)

  - `__PYVENV_LAUNCHER__` 環境變數

  - (Windows only) Application paths in the registry under "SoftwarePythonPythonCoreX.YPythonPath" of HKEY_CURRENT_USER and HKEY_LOCAL_MACHINE (where X.Y is the Python version).

- Path configuration output fields:

  - `PyConfig.base_exec_prefix`

  - `PyConfig.base_executable`

  - `PyConfig.base_prefix`

  - `PyConfig.exec_prefix`

  - `PyConfig.executable`

  - `PyConfig.module_search_paths_set`, `PyConfig.module_search_paths`

  - `PyConfig.prefix`

If at least one "output field" is not set, Python calculates the path configuration to fill unset fields. If `module_search_paths_set` is equal to `0`, `module_search_paths` is overridden and `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, `module_search_paths` will be used without modification.

Set `pathconfig_warnings` to `0` to suppress warnings when calculating the path configuration (Unix only, Windows does not log any warning).

If `base_prefix` or `base_exec_prefix` fields are not set, they inherit their value from `prefix` and `exec_prefix` respectively.

`Py_RunMain()` 和 `Py_Main()` 會修改 `sys.path`：

- If `run_filename` is set and is a directory which contains a `__main__.py` script, prepend `run_filename` to `sys.path`.

- 如果 `isolated` 為零：

  - If `run_module` is set, prepend the current directory to `sys.path`. Do nothing if the current directory cannot be read.

  - If `run_filename` is set, prepend the directory of the filename to `sys.path`.

  - Otherwise, prepend an empty string to `sys.path`.

If `site_import` is non-zero, `sys.path` can be modified by the `site` module. If `user_site_directory` is non-zero and the user's site-package directory exists, the `site` module appends the user's site-package directory to `sys.path`.

The following configuration files are used by the path configuration:

- `pyvenv.cfg`

- `._pth` file (ex: `python._pth`)

- `pybuilddir.txt`（僅限 Unix）

If a `._pth` file is present:

- 將 `isolated` 設定為 `1`。

- 將 `use_environment` 設定為 `0`。

- 將 `site_import` 設定為 `0`。

- Set `user_site_directory` to `0` (since 3.15).

- 將 `safe_path` 設定為 `1`。

If `home` is not set and a `pyvenv.cfg` file is present in the same directory as `executable`, or its parent, `prefix` and `exec_prefix` are set that location. When this happens, `base_prefix` and `base_exec_prefix` still keep their value, pointing to the base installation. See 虛擬環境 for more information.

The `__PYVENV_LAUNCHER__` environment variable is used to set `PyConfig.base_executable`.

在 3.14 版的變更: `prefix`, and `exec_prefix`, are now set to the `pyvenv.cfg` directory. This was previously done by `site`, therefore affected by `-S`.

在 3.15 版的變更: `user_site_directory` is now set to `0` when a `._pth` file is present.

## Py_GetArgcArgv()

void Py_GetArgcArgv(int *argc, wchar_t ***argv)

  Get the original command line arguments, before Python modified them.

  也請參與 `PyConfig.orig_argv` 成員。

## Delaying main module execution

In some embedding use cases, it may be desirable to separate interpreter initialization from the execution of the main module.

This separation can be achieved by setting `PyConfig.run_command` to the empty string during initialization (to prevent the interpreter from dropping into the interactive prompt), and then subsequently executing the desired main module code using `__main__.__dict__` as the global namespace.