PyTypeObject PyModule_Type
This instance of PyTypeObject represents the Python module type. This
is exposed to Python programs as types.ModuleType.
int PyModule_Check(PyObject *p)
Return true if p is a module object, or a subtype of a module object.
int PyModule_CheckExact(PyObject *p)
Return true if p is a module object, but not a subtype of
PyModule_Type.
PyObject* PyModule_NewObject(PyObject *name)
Return 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.
Changed in version 3.4: __package__ and __loader__ are set to None.
PyObject* PyModule_New(const char *name)
Return value: New reference.Similar to PyModule_NewObject(), but the name is a UTF-8 encoded
string instead of a Unicode object.
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 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.
char* PyModule_GetName(PyObject *module)
Similar to PyModule_GetNameObject() but return the name encoded to
'utf-8'.
void* PyModule_GetState(PyObject *module)
Return 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.
PyModuleDef* PyModule_GetDef(PyObject *module)
Return a pointer to the PyModuleDef struct from which the module was
created, or NULL if the module wasn't created from a definition.
PyObject* PyModule_GetFilenameObject(PyObject *module)
Return 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.
char* PyModule_GetFilename(PyObject *module)
Similar 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.
PyModuleDef
The 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.
PyModuleDef_Base m_base
Always initialize this member to PyModuleDef_HEAD_INIT.
char* m_name
Name for the new module.
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.
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.
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.
Changed in version 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.
inquiry m_clear
A clear function to call during GC clearing of the module object, or NULL if not needed.
freefunc m_free
A function to call during deallocation of the module object, or NULL if not needed.
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:
PyObject* PyModule_Create(PyModuleDef *def)
Create a new module object, given the definition in def. This behaves
like PyModule_Create2() with module_api_version set to
PYTHON_API_VERSION.
PyObject* PyModule_Create2(PyModuleDef *def, int module_api_version)
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.
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:
PyObject* PyModuleDef_Init(PyModuleDef *def)
Ensures 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_Slot
int slot
A slot ID, chosen from the available values explained below.
void* value
Value 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_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.
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_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)
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.
PyObject * PyModule_FromDefAndSpec(PyModuleDef *def, PyObject *spec)
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.
New in version 3.5.
PyObject * PyModule_FromDefAndSpec2(PyModuleDef *def, PyObject *spec, int module_api_version)
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.
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.
int PyModule_ExecDef(PyObject *module, PyModuleDef *def)
Process any execution slots (Py_mod_exec) given in def.
New in version 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.
New in version 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.
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:
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. Return -1 on error, 0 on success.
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.
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)
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.
New in version 3.3.
int PyState_RemoveModule(PyModuleDef *def)
Removes the module object created from def from the interpreter state.
New in version 3.3.