PyModule_TypeThis instance of PyTypeObject represents the Python module type. This is exposed to Python programs as types.ModuleType.
PyModule_CheckReturn true if p is a module object, or a subtype of a module object.
PyModule_CheckExactReturn true if p is a module object, but not a subtype of PyModule_Type.
PyModule_NewObjectReturn a new module object with the __name__ attribute set to name. The module's __name__, __doc__, __package__, and __loader__ attributes are filled in (all but __name__ are set to None); the caller is responsible for providing a __file__ attribute.
New in version 3.3.
PyModule_NewSimilar to PyModule_NewObject(), but the name is a UTF-8 encoded string instead of a Unicode object.
PyModule_GetDictReturn 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__.
PyModule_GetNameObjectReturn 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.
New in version 3.3.
PyModule_GetNameSimilar to PyModule_GetNameObject() but return the name encoded to 'utf-8'.
PyModule_GetStateReturn the 'state? of the module, that is, a pointer to the block of memory allocated at module creation time, or NULL. See PyModuleDef.m_size.
PyModule_GetDefReturn a pointer to the PyModuleDef struct from which the module was created, or NULL if the module wasn?t created from a definition.
PyModule_GetFilenameObjectReturn the name of the file from which module was loaded using module's __file__ attribute. If this is not defined, or if it is not a unicode string, raise SystemError and return NULL; otherwise return a reference to a Unicode object.
New in version 3.2.
PyModule_GetFilenameSimilar to PyModule_GetFilenameObject() but return the filename encoded to ?utf-8?.
Deprecated since version 3.2: PyModule_GetFilename() raises UnicodeEncodeError on unencodable filenames, use PyModule_GetFilenameObject() instead.
Modules objects are usually created from extension modules (shared libraries which export an initialization function), or compiled-in modules (where the initialization function is added using PyImport_AppendInittab()). See Building C and C++ Extensions or Extending Embedded Python for details.
The initialization function can either pass a module definition instance to PyModule_Create(), and return the resulting module object, or request ?multi-phase initialization? by returning the definition struct itself.
PyModuleDefThe module definition struct, which holds all information needed to create a module object. There is usually only one statically initialized variable of this type for each module.
m_baseAlways initialize this member to PyModuleDef_HEAD_INIT.
m_nameName for the new module.
m_docDocstring for the module; usually a docstring variable created with PyDoc_STRVAR() is used.
m_sizeModule 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.
Setting it to a non-negative value means that the module can be re-initialized and specifies the additional amount of memory it requires for its state. Non-negative m_size is required for multi-phase initialization.
See PEP 3121 for more details.
m_methodsA pointer to a table of module-level functions, described by PyMethodDef values. Can be NULL if no functions are present.
m_slotsAn array of slot definitions for multi-phase initialization, terminated by a {0, NULL} entry. When using single-phase initialization, m_slots must be NULL.
Changed in version 3.5: Prior to version 3.5, this member was always set to NULL, and was defined as:
m_traverseA traversal function to call during GC traversal of the module object, or NULL if not needed. This function may be called before module state is allocated (PyModule_GetState() may return NULL), and before the Py_mod_exec function is executed.
m_clearA clear function to call during GC clearing of the module object, or NULL if not needed. This function may be called before module state is allocated (PyModule_GetState() may return NULL), and before the Py_mod_exec function is executed.
m_freeA function to call during deallocation of the module object, or NULL if not needed. This function may be called before module state is allocated (PyModule_GetState() may return NULL), and before the Py_mod_exec function is executed.
The module initialization function may create and return the module object directly. This is referred to as 'single-phase initialization?, and uses one of the following two module creation functions:
PyModule_CreateCreate a new module object, given the definition in def. This behaves like PyModule_Create2() with module_api_version set to PYTHON_API_VERSION.
PyModule_Create2Create 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.
Note
Most uses of this function should be using PyModule_Create() instead; only use this if you are sure you need it.
Before it is returned from in the initialization function, the resulting module object is typically populated using functions like PyModule_AddObject().
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:
PyModuleDef_InitEnsures a module definition is a properly initialized Python object that correctly reports its type and reference count.
Returns def cast to PyObject*, or NULL if an error occurred.
New in version 3.5.
The m_slots member of the module definition must point to an array of PyModuleDef_Slot structures:
PyModuleDef_SlotslotA slot ID, chosen from the available values explained below.
valueValue of the slot, whose meaning depends on the slot ID.
New in version 3.5.
The m_slots array must be terminated by a slot with id 0.
The available slot types are:
Py_mod_createSpecifies 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:
create_moduleThe 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.
Multiple Py_mod_create slots may not be specified in one module definition.
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_execSpecifies 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:
If multiple Py_mod_exec slots are specified, they are processed in the order they appear in the m_slots array.
See PEP 489 for more details on multi-phase initialization.
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.
PyModule_FromDefAndSpecCreate 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.
New in version 3.5.
PyModule_FromDefAndSpec2Create 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.
Note
Most uses of this function should be using PyModule_FromDefAndSpec() instead; only use this if you are sure you need it.
New in version 3.5.
PyModule_ExecDefProcess any execution slots (Py_mod_exec) given in def.
New in version 3.5.
PyModule_SetDocStringSet the docstring for module to docstring. This function is called automatically when creating a module from PyModuleDef, using either PyModule_Create or PyModule_FromDefAndSpec.
New in version 3.5.
PyModule_AddFunctionsAdd 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.
New in version 3.5.
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:
PyModule_AddObjectAdd 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.
Note
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;
}
PyModule_AddIntConstantAdd 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.
PyModule_AddStringConstantAdd 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.
PyModule_AddIntMacroAdd 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.
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.
PyState_FindModuleReturns 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.
PyState_AddModuleAttaches 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).
Return 0 on success or -1 on failure.
New in version 3.3.
PyState_RemoveModuleRemoves the module object created from def from the interpreter state. Return 0 on success or -1 on failure.
New in version 3.3.
Py_INCREF(spam);
if (PyModule_AddObject(module, "spam", spam) < 0) {
Py_DECREF(module);
Py_DECREF(spam);
return NULL;
}
PyModule_AddIntConstantAdd 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.
PyModule_AddStringConstantAdd 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.
PyModule_AddIntMacroAdd 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.
PyModule_AddStringMacroAdd a string constant to module.
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.
PyState_FindModuleReturns 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.
PyState_AddModuleAttaches 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).
Return 0 on success or -1 on failure.
New in version 3.3.
PyState_RemoveModuleRemoves the module object created from def from the interpreter state. Return 0 on success or -1 on failure.
New in version 3.3.
