Objeto Module

PyTypeObject PyModule_Type

Esta instância de PyTypeObject representa o tipo de módulo Python. Isso é exposto a programas Python como types.ModuleType.

int PyModule_Check(PyObject *p)

Retorna true se p for um objeto de módulo ou um subtipo de um objeto de módulo. Esta função sempre é bem-sucedida.

int PyModule_CheckExact(PyObject *p)

Retorna true se p for um objeto de módulo, mas não um subtipo de PyModule_Type. Essa função é sempre bem-sucedida.

PyObject* PyModule_NewObject(PyObject *name)

Return value: New reference.

Retorna um novo objeto de módulo com o atributo __name__`definido como *nome*. Os atributos de módulo :attr:`__name__,:attr:__doc__,:attr:__package__ e __loader__ são preenchidos (todos exceto __name__ são definidos como None); O caller é responsásvel por providenciar um atributo __file__.

Novo na versão 3.3.

Alterado na versão 3.4: __package__ e __loader__ são definidos como None.

PyObject* PyModule_New(const char *name)

Return value: New reference.

Semelhante a PyModule_NewObject(), mas o nome é uma string codificada em UTF-8 em vez de um objeto Unicode.

PyObject* PyModule_GetDict(PyObject *module)

Return value: Borrowed reference.

Return the dictionary object that implements module’s namespace; this object is the same as the __dict__ attribute of the module object. If module is not a module object (or a subtype of a module object), SystemError is raised and NULL is returned.

It is recommended extensions use other PyModule_*() and PyObject_*() functions rather than directly manipulate a module’s __dict__.

PyObject* PyModule_GetNameObject(PyObject *module)

Return value: New reference.

Return module’s __name__ value. If the module does not provide one, or if it is not a string, SystemError is raised and NULL is returned.

Novo na versão 3.3.

const char* PyModule_GetName(PyObject *module)

Semelhante a PyModule_GetNameObject() mas retorna o nome codificado em 'utf-8'

void* PyModule_GetState(PyObject *module)

Retorna o “estado” do módulo, ou seja, um ponteiro para o bloco de memória alocado no momento de criação do módulo, ou NULL. Ver PyModuleDef.m_size.

PyModuleDef* PyModule_GetDef(PyObject *module)

Retorna um ponteiro para a estrutura PyModuleDef`da qual o módulo foi criado, ou ``NULL` se o módulo não foi criado de uma definição.

PyObject* PyModule_GetFilenameObject(PyObject *module)

Return value: New reference.

Retorna o nome do arquivo do qual o módulo foi carregado usando o atributo __file__ do módulo. Se não estiver definido, ou se não for uma string unicode, levanta SystemError e retorna``NULL``; Caso contrário, retorna uma referência a um objeto Unicode.

Novo na versão 3.2.

const char* PyModule_GetFilename(PyObject *module)

Semelhante a PyModule_GetFilenameObject() mas retorna o nome do arquivo codificado em ‘utf-8’.

Obsoleto desde a versão 3.2: PyModule_GetFilename() raises UnicodeEncodeError on unencodable filenames, use PyModule_GetFilenameObject() instead.

Inicializando módulos C

Objetos de módulos são geralmente criados a partir de módulos de extensão (bibliotecas compartilhadas que exportam uma função de inicialização), ou módulos compilados (onde a função de inicialização é adicionada usando PyImport_AppendInittab()). Ver Construindo extensões C e C++ ou Extending Embedded Python para mais detalhes.

A função de inicialização pode passar uma instância de definição de módulo para PyModule_Create() e retornar o objeto de módulo resultante ou solicitar “inicialização multifásica” retornando a própria estrutura de definição.

PyModuleDef

A estrutura de definição de módulo, que contém todas as informações necessária para criar um objeto de módulo. Geralmente, há apenas uma variável inicializada estaticamente desse tipo para cada módulo.

PyModuleDef_Base m_base

Sempre inicializa este membro para PyModuleDef_HEAD_INIT.

const char *m_name

Nome para o novo módulo.

const char *m_doc

Docstring for the module; usually a docstring variable created with PyDoc_STRVAR is used.

Py_ssize_t m_size

Module state may be kept in a per-module memory area that can be retrieved with PyModule_GetState(), rather than in static globals. This makes modules safe for use in multiple sub-interpreters.

This memory area is allocated based on m_size on module creation, and freed when the module object is deallocated, after the m_free function has been called, if present.

Setting m_size to -1 means that the module does not support sub-interpreters, because it has global state.

Defini-lo como um valor não negativo significa que o módulo pode ser reinicializado e especifica a quantidade adicional de memória necessária para seu estado. m_size não negativo é necessário para inicialização multifásica.

Ver PEP 3121 para mais detalhes.

PyMethodDef* m_methods

A pointer to a table of module-level functions, described by PyMethodDef values. Can be NULL if no functions are present.

PyModuleDef_Slot* m_slots

An array of slot definitions for multi-phase initialization, terminated by a {0, NULL} entry. When using single-phase initialization, m_slots must be NULL.

Alterado na versão 3.5: Prior to version 3.5, this member was always set to NULL, and was defined as:

inquiry m_reload

traverseproc m_traverse

A traversal function to call during GC traversal of the module object, or NULL if not needed.

This function is not called if the module state was requested but is not allocated yet. This is the case immediately after the module is created and before the module is executed (Py_mod_exec function). More precisely, this function is not called if m_size is greater than 0 and the module state (as returned by PyModule_GetState()) is NULL.

Alterado na versão 3.9: Não é mais chamado antes que o estado do módulo seja alocado.

inquiry m_clear

A clear function to call during GC clearing of the module object, or NULL if not needed.

This function is not called if the module state was requested but is not allocated yet. This is the case immediately after the module is created and before the module is executed (Py_mod_exec function). More precisely, this function is not called if m_size is greater than 0 and the module state (as returned by PyModule_GetState()) is NULL.

Like PyTypeObject.tp_clear, this function is not always called before a module is deallocated. For example, when reference counting is enough to determine that an object is no longer used, the cyclic garbage collector is not involved and m_free is called directly.

Alterado na versão 3.9: Não é mais chamado antes que o estado do módulo seja alocado.

freefunc m_free

Uma função para ser chamada durante a desalocação do objeto do módulo, ou NULL se não for necessário.

This function is not called if the module state was requested but is not allocated yet. This is the case immediately after the module is created and before the module is executed (Py_mod_exec function). More precisely, this function is not called if m_size is greater than 0 and the module state (as returned by PyModule_GetState()) is NULL.

Alterado na versão 3.9: Não é mais chamado antes que o estado do módulo seja alocado.

inicialização de fase única

A função de inicialização do módulo pode criar e retornar o objeto do módulo diretamente. Isso é chamado de “inicialização de fase única” e usa uma das duas funções de criação de módulo a seguir:

PyObject* PyModule_Create(PyModuleDef *def)

Return value: New reference.

Cria um novo objeto de módulo, dada a definição em def. Isso se comporta como PyModule_Create2() com module_api_version definido como PYTHON_API_VERSION

PyObject* PyModule_Create2(PyModuleDef *def, int module_api_version)

Return value: New reference.

Create a new module object, given the definition in def, assuming the API version module_api_version. If that version does not match the version of the running interpreter, a RuntimeWarning is emitted.

Nota

A maioria dos usos dessa função deve ser feita com:c:func:PyModule_Create; use-o apenas se tiver certeza de que precisa.

Before it is returned from in the initialization function, the resulting module object is typically populated using functions like PyModule_AddObject().

Inicialização multifásica

An alternate way to specify extensions is to request “multi-phase initialization”. Extension modules created this way behave more like Python modules: the initialization is split between the creation phase, when the module object is created, and the execution phase, when it is populated. The distinction is similar to the __new__() and __init__() methods of classes.

Unlike modules created using single-phase initialization, these modules are not singletons: if the sys.modules entry is removed and the module is re-imported, a new module object is created, and the old module is subject to normal garbage collection – as with Python modules. By default, multiple modules created from the same definition should be independent: changes to one should not affect the others. This means that all state should be specific to the module object (using e.g. using PyModule_GetState()), or its contents (such as the module’s __dict__ or individual classes created with PyType_FromSpec()).

All modules created using multi-phase initialization are expected to support sub-interpreters. Making sure multiple modules are independent is typically enough to achieve this.

To request multi-phase initialization, the initialization function (PyInit_modulename) returns a PyModuleDef instance with non-empty m_slots. Before it is returned, the PyModuleDef instance must be initialized with the following function:

PyObject* PyModuleDef_Init(PyModuleDef *def)

Return value: Borrowed reference.

Garante que uma definição de módulo é um objeto Python devidamente inicializado que reporta corretamente seu tipo e contagem de referências.

Returns def cast to PyObject*, or NULL if an error occurred.

Novo na versão 3.5.

The m_slots member of the module definition must point to an array of PyModuleDef_Slot structures:

PyModuleDef_Slot

int slot

Um ID de lot, escolhido a partir dos valores disponíveis explicados abaixo.

void* value

Valor do slot, cujo significado depende do ID do slot.

Novo na versão 3.5.

The m_slots array must be terminated by a slot with id 0.

Os tipos de slot disponíveis são:

Py_mod_create

Specifies a function that is called to create the module object itself. The value pointer of this slot must point to a function of the signature:

PyObject* create_module(PyObject *spec, PyModuleDef *def)

The function receives a ModuleSpec instance, as defined in PEP 451, and the module definition. It should return a new module object, or set an error and return NULL.

This function should be kept minimal. In particular, it should not call arbitrary Python code, as trying to import the same module again may result in an infinite loop.

Múltiplos slots Py_mod_create podem não estar especificados em uma definição de módulo.

If Py_mod_create is not specified, the import machinery will create a normal module object using PyModule_New(). The name is taken from spec, not the definition, to allow extension modules to dynamically adjust to their place in the module hierarchy and be imported under different names through symlinks, all while sharing a single module definition.

There is no requirement for the returned object to be an instance of PyModule_Type. Any type can be used, as long as it supports setting and getting import-related attributes. However, only PyModule_Type instances may be returned if the PyModuleDef has non-NULL m_traverse, m_clear, m_free; non-zero m_size; or slots other than Py_mod_create.

Py_mod_exec

Specifies a function that is called to execute the module. This is equivalent to executing the code of a Python module: typically, this function adds classes and constants to the module. The signature of the function is:

int exec_module(PyObject* module)

Se vários slots Py_mod_exec forem especificados, eles serão processados na ordem em que aparecem no vetor m_slots.

Ver PEP 489 para obter mais detalhes sobre a inicialização multifásica.

Funções de criação de módulo de baixo nível

The following functions are called under the hood when using multi-phase initialization. They can be used directly, for example when creating module objects dynamically. Note that both PyModule_FromDefAndSpec and PyModule_ExecDef must be called to fully initialize a module.

PyObject * PyModule_FromDefAndSpec(PyModuleDef *def, PyObject *spec)

Return value: New reference.

Create a new module object, given the definition in module and the ModuleSpec spec. This behaves like PyModule_FromDefAndSpec2() with module_api_version set to PYTHON_API_VERSION.

Novo na versão 3.5.

PyObject * PyModule_FromDefAndSpec2(PyModuleDef *def, PyObject *spec, int module_api_version)

Return value: New reference.

Create a new module object, given the definition in module and the ModuleSpec spec, assuming the API version module_api_version. If that version does not match the version of the running interpreter, a RuntimeWarning is emitted.

Nota

Most uses of this function should be using PyModule_FromDefAndSpec() instead; only use this if you are sure you need it.

Novo na versão 3.5.

int PyModule_ExecDef(PyObject *module, PyModuleDef *def)

Process any execution slots (Py_mod_exec) given in def.

Novo na versão 3.5.

int PyModule_SetDocString(PyObject *module, const char *docstring)

Set the docstring for module to docstring. This function is called automatically when creating a module from PyModuleDef, using either PyModule_Create or PyModule_FromDefAndSpec.

Novo na versão 3.5.

int PyModule_AddFunctions(PyObject *module, PyMethodDef *functions)

Add the functions from the NULL terminated functions array to module. Refer to the PyMethodDef documentation for details on individual entries (due to the lack of a shared module namespace, module level “functions” implemented in C typically receive the module as their first parameter, making them similar to instance methods on Python classes). This function is called automatically when creating a module from PyModuleDef, using either PyModule_Create or PyModule_FromDefAndSpec.

Novo na versão 3.5.

Support functions

The module initialization function (if using single phase initialization) or a function called from a module execution slot (if using multi-phase initialization), can use the following functions to help initialize the module state:

int PyModule_AddObject(PyObject *module, const char *name, PyObject *value)

Add an object to module as name. This is a convenience function which can be used from the module’s initialization function. This steals a reference to value on success. Return -1 on error, 0 on success.

Nota

Unlike other functions that steal references, PyModule_AddObject() only decrements the reference count of value on success.

This means that its return value must be checked, and calling code must Py_DECREF() value manually on error. Example usage:

Py_INCREF(spam);
if (PyModule_AddObject(module, "spam", spam) < 0) {
    Py_DECREF(module);
    Py_DECREF(spam);
    return NULL;
}

int PyModule_AddIntConstant(PyObject *module, const char *name, long value)

Add an integer constant to module as name. This convenience function can be used from the module’s initialization function. Return -1 on error, 0 on success.

int PyModule_AddStringConstant(PyObject *module, const char *name, const char *value)

Add a string constant to module as name. This convenience function can be used from the module’s initialization function. The string value must be NULL-terminated. Return -1 on error, 0 on success.

int PyModule_AddIntMacro(PyObject *module, macro)

Add an int constant to module. The name and the value are taken from macro. For example PyModule_AddIntMacro(module, AF_INET) adds the int constant AF_INET with the value of AF_INET to module. Return -1 on error, 0 on success.

int PyModule_AddStringMacro(PyObject *module, macro)

Add a string constant to module.

int PyModule_AddType(PyObject *module, PyTypeObject *type)

Add a type object to module. The type object is finalized by calling internally PyType_Ready(). The name of the type object is taken from the last component of tp_name after dot. Return -1 on error, 0 on success.

Novo na versão 3.9.

Pesquisa por módulos

Single-phase initialization creates singleton modules that can be looked up in the context of the current interpreter. This allows the module object to be retrieved later with only a reference to the module definition.

These functions will not work on modules created using multi-phase initialization, since multiple such modules can be created from a single definition.

PyObject* PyState_FindModule(PyModuleDef *def)

Return value: Borrowed reference.

Returns the module object that was created from def for the current interpreter. This method requires that the module object has been attached to the interpreter state with PyState_AddModule() beforehand. In case the corresponding module object is not found or has not been attached to the interpreter state yet, it returns NULL.

int PyState_AddModule(PyObject *module, PyModuleDef *def)

Attaches the module object passed to the function to the interpreter state. This allows the module object to be accessible via PyState_FindModule().

Only effective on modules created using single-phase initialization.

Python calls PyState_AddModule automatically after importing a module, so it is unnecessary (but harmless) to call it from module initialization code. An explicit call is needed only if the module’s own init code subsequently calls PyState_FindModule. The function is mainly intended for implementing alternative import mechanisms (either by calling it directly, or by referring to its implementation for details of the required state updates).

The caller must hold the GIL.

Return 0 on success or -1 on failure.

Novo na versão 3.3.

int PyState_RemoveModule(PyModuleDef *def)

Removes the module object created from def from the interpreter state. Return 0 on success or -1 on failure.

The caller must hold the GIL.

Novo na versão 3.3.