胶囊 ¶
参考 为扩展模块提供 C API for more information on using these objects.
Added in version 3.1.
参考 为扩展模块提供 C API for more information on using these objects.
Added in version 3.1.
此子类型的
PyObject
represents an opaque value, useful for C extension modules who need to pass an opaque value (as a
void
*
pointer) through Python code to other C code. It is often used to make a C function pointer defined in one module available to other modules, so the regular import mechanism can be used to access C APIs defined in dynamically loaded modules.
The type of a destructor callback for a capsule. Defined as:
typedef void (*PyCapsule_Destructor)(PyObject *);
见
PyCapsule_New()
for the semantics of PyCapsule_Destructor callbacks.
返回 True 若其自变量是
PyCapsule
. This function always succeeds.
创建
PyCapsule
encapsulating the
pointer
。
pointer
argument may not be
NULL
.
On failure, set an exception and return
NULL
.
The
name
string may either be
NULL
or a pointer to a valid C string. If non-
NULL
, this string must outlive the capsule. (Though it is permitted to free it inside the
destructor
)。
若
destructor
argument is not
NULL
, it will be called with the capsule as its argument when it is destroyed.
If this capsule will be stored as an attribute of a module, the
name
should be specified as
modulename.attributename
. This will enable other modules to import the capsule using
PyCapsule_Import()
.
Retrieve the
pointer
stored in the capsule. On failure, set an exception and return
NULL
.
The
name
parameter must compare exactly to the name stored in the capsule. If the name stored in the capsule is
NULL
，
name
passed in must also be
NULL
. Python uses the C function
strcmp()
to compare capsule names.
Return the current destructor stored in the capsule. On failure, set an exception and return
NULL
.
It is legal for a capsule to have a
NULL
destructor. This makes a
NULL
return code somewhat ambiguous; use
PyCapsule_IsValid()
or
PyErr_Occurred()
以消除歧义。
Return the current context stored in the capsule. On failure, set an exception and return
NULL
.
It is legal for a capsule to have a
NULL
context. This makes a
NULL
return code somewhat ambiguous; use
PyCapsule_IsValid()
or
PyErr_Occurred()
以消除歧义。
Return the current name stored in the capsule. On failure, set an exception and return
NULL
.
It is legal for a capsule to have a
NULL
name. This makes a
NULL
return code somewhat ambiguous; use
PyCapsule_IsValid()
or
PyErr_Occurred()
以消除歧义。
Import a pointer to a C object from a capsule attribute in a module. The
name
parameter should specify the full name to the attribute, as in
module.attribute
。
name
stored in the capsule must match this string exactly.
Return the capsule’s internal
pointer
on success. On failure, set an exception and return
NULL
.
3.3 版改变： no_block has no effect anymore.
Determines whether or not
capsule
is a valid capsule. A valid capsule is non-
NULL
, passes
PyCapsule_CheckExact()
, has a non-
NULL
pointer stored in it, and its internal name matches the
name
parameter. (See
PyCapsule_GetPointer()
for information on how capsule names are compared.)
In other words, if
PyCapsule_IsValid()
returns a true value, calls to any of the accessors (any function starting with
PyCapsule_Get
) are guaranteed to succeed.
Return a nonzero value if the object is valid and matches the name passed in. Return
0
otherwise. This function will not fail.
Set the context pointer inside capsule to context .
返回
0
on success. Return nonzero and set an exception on failure.
Set the destructor inside capsule to destructor .
返回
0
on success. Return nonzero and set an exception on failure.
Set the name inside
capsule
to
name
. If non-
NULL
, the name must outlive the capsule. If the previous
name
stored in the capsule was not
NULL
, no attempt is made to free it.
返回
0
on success. Return nonzero and set an exception on failure.
Set the void pointer inside
capsule
to
pointer
. The pointer may not be
NULL
.
返回
0
on success. Return nonzero and set an exception on failure.