Python Initialization Configuration¶

PyInitConfig C API¶

Added in version 3.14.

Python can be initialized with Py_InitializeFromInitConfig().

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

Example¶

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;
    }
}

Create Config¶

struct PyInitConfig¶: Opaque structure to configure the Python initialization.

PyInitConfig *PyInitConfig_Create(void)¶

Create a new initialization configuration using Isolated Configuration default values.

It must be freed by PyInitConfig_Free().

Return NULL on memory allocation failure.

void PyInitConfig_Free(PyInitConfig *config)¶

Free memory of the initialization configuration config.

If config is NULL, no operation is performed.

Error Handling¶

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

Get the config error message.

Set *err_msg and return 1 if an error is set.
Set *err_msg to NULL and return 0 otherwise.

An error message is a UTF-8 encoded string.

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)¶

Test if the configuration has an option called name.

Return 1 if the option exists, or return 0 otherwise.

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