C API for Handwritten Code

In this section we describe the API that can be used by handwritten code in specification files.

SIP_API_MAJOR_NR

This is a C preprocessor symbol that defines the major number of the SIP API. Its value is a number. There is no direct relationship between this and the SIP version number.

SIP_API_MINOR_NR

This is a C preprocessor symbol that defines the minor number of the SIP API. Its value is a number. There is no direct relationship between this and the SIP version number.

SIP_BLOCK_THREADS

This is a C preprocessor macro that will make sure the Python Global Interpreter Lock (GIL) is acquired. Python API calls must only be made when the GIL has been acquired. There must be a corresponding SIP_UNBLOCK_THREADS at the same lexical scope.

SIP_NO_CONVERTORS

This is a flag used by various type convertors that suppresses the use of a type’s %ConvertToTypeCode.

SIP_NOT_NONE

This is a flag used by various type convertors that causes the conversion to fail if the Python object being converted is Py_None.

SIP_OWNS_MEMORY

New in version 4.15.2.

This is a flag used by various array constructors that species that the array owns the memory that holds the array’s contents.

SIP_PROTECTED_IS_PUBLIC

New in version 4.10.

This is a C preprocessor symbol that is defined automatically by the build system to specify that the generated code is being compiled with protected redefined as public. This allows handwritten code to determine if the generated helper functions for accessing protected C++ functions are available (see %MethodCode).

SIP_READ_ONLY

New in version 4.15.2.

This is a flag used by various array constructors that species that the array is read-only.

SIP_RELEASE_GIL(sip_gilstate_t sipGILState)

New in version 4.14.4.

This is called from the handwritten code specified with the VirtualErrorHandler in order to release the Python Global Interpreter Lock (GIL) prior to changing the execution path (e.g. by throwing a C++ exception). It should not be called under any other circumstances.

Parameters:
  • sipGILState – an opaque value provided to the handwritten code by SIP.
SIP_SSIZE_T

This is a C preprocessor macro that is defined as Py_ssize_t for Python v2.5 and later, and as int for earlier versions of Python. It makes it easier to write PEP 353 compliant handwritten code.

SIP_SSIZE_T_FORMAT

New in version 4.15.4.

This is a C preprocessor macro that is defined as %zd for Python v2.5 and later, and as %d for earlier versions of Python. It makes it easier to write PEP 353 compliant handwritten code.

SIP_UNBLOCK_THREADS

This is a C preprocessor macro that will restore the Python Global Interpreter Lock (GIL) to the state it was prior to the corresponding SIP_BLOCK_THREADS.

SIP_USE_PYCAPSULE

New in version 4.11.

This is a C preprocessor symbol that is defined when PyCapsule objects are being used rather than the (now deprecated) PyCObject objects.

SIP_VERSION

This is a C preprocessor symbol that defines the SIP version number represented as a 3 part hexadecimal number (e.g. v5.0.0 is represented as 0x050000).

SIP_VERSION_STR

This is a C preprocessor symbol that defines the SIP version number represented as a string. For development versions it will contain either .dev or -snapshot-.

sipErrorState sipBadCallableArg(int arg_nr, PyObject *arg)

New in version 4.10.

This is called from %MethodCode to raise a Python exception when an argument to a function, a C++ constructor or method is found to have an unexpected type. This should be used when the %MethodCode does additional type checking of the supplied arguments.

Parameters:
  • arg_nr – the number of the argument. Arguments are numbered from 0 but are numbered from 1 in the detail of the exception.
  • arg – the argument.
Returns:

the value that should be assigned to sipError.
void sipBadCatcherResult(PyObject *method)

This raises a Python exception when the result of a Python reimplementation of a C++ method doesn’t have the expected type. It is normally called by handwritten code specified with the %VirtualCatcherCode directive.

Parameters:
  • method – the Python method and would normally be the supplied sipMethod.
void sipBadLengthForSlice(SIP_SSIZE_T seqlen, SIP_SSIZE_T slicelen)

This raises a Python exception when the length of a slice object is inappropriate for a sequence-like object. It is normally called by handwritten code specified for __setitem__() methods.

Parameters:
  • seqlen – the length of the sequence.
  • slicelen – the length of the slice.
sipBufferInfoDef

New in version 4.19.

This C structure is used with sipGetBufferInfo() and sipReleaseBufferInfo() and encapsulates information provided by a Python object that implements the buffer protocol. The structure elements are as follows.

void *bi_buf

The address of the buffer.

PyObject *bi_obj

A reference to the object that implements the buffer protocol.

SIP_SSIZE_T bi_len

The length of the buffer in bytes.

char *bi_format

The format of each element of the buffer.

PyObject *sipBuildResult(int *iserr, const char *format, …)

This creates a Python object based on a format string and associated values in a similar way to the Python Py_BuildValue() function.

Parameters:
  • iserr – if this is not NULL then the location it points to is set to a non-zero value.
  • format – the string of format characters.
Returns:

If there was an error then NULL is returned and a Python exception is raised.

If the format string begins and ends with parentheses then a tuple of objects is created. If it contains more than one format character then parentheses must be specified.

In the following description the first letter is the format character, the entry in parentheses is the Python object type that the format character will create, and the entry in brackets are the types of the C/C++ values to be passed.

a (string) [char]
Convert a C/C++ char to a Python v2 or v3 string object.
b (boolean) [int]
Convert a C/C++ int to a Python boolean.
c (string/bytes) [char]
Convert a C/C++ char to a Python v2 string object or a Python v3 bytes object.
d (float) [double]
Convert a C/C++ double to a Python floating point number.
e (integer) [enum]
Convert an anonymous C/C++ enum to a Python integer.
f (float) [float]
Convert a C/C++ float to a Python floating point number.
g (string/bytes) [char *, SIP_SSIZE_T]
Convert a C/C++ character array and its length to a Python v2 string object or a Python v3 bytes object. If the array is NULL then the length is ignored and the result is Py_None.
h (integer) [short]
Convert a C/C++ short to a Python integer.
i (integer) [int]
Convert a C/C++ int to a Python integer.
l (long) [long]
Convert a C/C++ long to a Python integer.
m (long) [unsigned long]
Convert a C/C++ unsigned long to a Python long.
n (long) [long long]
Convert a C/C++ long long to a Python long.
o (long) [unsigned long long]
Convert a C/C++ unsigned long long to a Python long.
r (wrapped instance) [type *, SIP_SSIZE_T, const sipTypeDef *]
Convert an array of C structures, C++ classes or mapped type instances to a Python tuple. Note that copies of the array elements are made.
s (string/bytes) [char *]
Convert a C/C++ '\0' terminated string to a Python v2 string object or a Python v3 bytes object. If the string pointer is NULL then the result is Py_None.
t (long) [unsigned short]
Convert a C/C++ unsigned short to a Python long.
u (long) [unsigned int]
Convert a C/C++ unsigned int to a Python long.
w (unicode/string) [wchar_t]
Convert a C/C++ wide character to a Python v2 unicode object or a Python v3 string object.
x (unicode/string) [wchar_t *]
Convert a C/C++ L'\0' terminated wide character string to a Python v2 unicode object or a Python v3 string object. If the string pointer is NULL then the result is Py_None.
A (string) [char *]
Convert a C/C++ '\0' terminated string to a Python v2 or v3 string object. If the string pointer is NULL then the result is Py_None.
B (wrapped instance) [type *, sipWrapperType *, PyObject *]

Deprecated since version 4.8: Use N instead.

Convert a new C structure or a new C++ class instance to a Python class instance object. Ownership of the structure or instance is determined by the PyObject * argument. If it is NULL and the instance has already been wrapped then the ownership is unchanged. If it is NULL or Py_None then ownership will be with Python. Otherwise ownership will be with C/C++ and the instance associated with the PyObject * argument. The Python class is influenced by any applicable %ConvertToSubClassCode code.

C (wrapped instance) [type *, sipWrapperType *, PyObject *]

Deprecated since version 4.8: Use D instead.

Convert a C structure or a C++ class instance to a Python class instance object. If the structure or class instance has already been wrapped then the result is a new reference to the existing class instance object. Ownership of the structure or instance is determined by the PyObject * argument. If it is NULL and the instance has already been wrapped then the ownership is unchanged. If it is NULL and the instance is newly wrapped then ownership will be with C/C++. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and the instance associated with the PyObject * argument via a call to sipTransferTo(). The Python class is influenced by any applicable %ConvertToSubClassCode code.

D (wrapped instance) [type *, const sipTypeDef *, PyObject *]
Convert a C structure, C++ class or mapped type instance to a Python object. If the instance has already been wrapped then the result is a new reference to the existing object. Ownership of the instance is determined by the PyObject * argument. If it is NULL and the instance has already been wrapped then the ownership is unchanged. If it is NULL and the instance is newly wrapped then ownership will be with C/C++. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack(). Otherwise ownership is transferred to C/C++ and the instance associated with the PyObject * argument via a call to sipTransferTo(). The Python class is influenced by any applicable %ConvertToSubClassCode code.
E (wrapped enum) [enum, PyTypeObject *]

Deprecated since version 4.8: Use F instead.

Convert a named C/C++ enum to an instance of the corresponding Python named enum type.

F (wrapped enum) [enum, sipTypeDef *]
Convert a named C/C++ enum to an instance of the corresponding Python named enum type.
G (unicode) [wchar_t *, SIP_SSIZE_T]
Convert a C/C++ wide character array and its length to a Python unicode object. If the array is NULL then the length is ignored and the result is Py_None.
L (integer) [char]

New in version 4.12.

Convert a C/C++ char to a Python integer.

M (long) [unsigned char]

New in version 4.12.

Convert a C/C++ unsigned char to a Python long.

N (wrapped instance) [type *, sipTypeDef *, PyObject *]
Convert a new C structure, C++ class or mapped type instance to a Python object. Ownership of the instance is determined by the PyObject * argument. If it is NULL and the instance has already been wrapped then the ownership is unchanged. If it is NULL or Py_None then ownership will be with Python. Otherwise ownership will be with C/C++ and the instance associated with the PyObject * argument. The Python class is influenced by any applicable %ConvertToSubClassCode code.
R (object) [PyObject *]
The result is value passed without any conversions. The reference count is unaffected, i.e. a reference is taken.
S (object) [PyObject *]
The result is value passed without any conversions. The reference count is incremented.
V (sip.voidptr) [void *]
Convert a C/C++ void * to a Python sip.voidptr object.
z (object) [const char *, void *]

New in version 4.14.1.

Convert a C/C++ void * to a Python named capsule object.

PyObject *sipCallMethod(int *iserr, PyObject *method, const char *format, …)

This calls a Python method passing a tuple of arguments based on a format string and associated values in a similar way to the Python PyObject_CallObject() function.

Parameters:
  • iserr – if this is not NULL then the location it points to is set to a non-zero value if there was an error.
  • method – the Python bound method to call.
  • format – the string of format characters (see sipBuildResult()).
Returns:

If there was an error then NULL is returned and a Python exception is raised.

It is normally called by handwritten code specified with the %VirtualCatcherCode directive with method being the supplied sipMethod.

int sipCanConvertToEnum(PyObject *obj, const sipTypeDef *td)

This checks if a Python object can be converted to a named enum.

Parameters:
Returns:

a non-zero value if the object can be converted.
int sipCanConvertToInstance(PyObject *obj, sipWrapperType *type, int flags)

Deprecated since version 4.8: Use sipCanConvertToType() instead.

This checks if a Python object can be converted to an instance of a C structure or C++ class.

Parameters:
Returns:

a non-zero value if the object can be converted.
int sipCanConvertToMappedType(PyObject *obj, const sipMappedType *mt, int flags)

Deprecated since version 4.8: Use sipCanConvertToType() instead.

This checks if a Python object can be converted to an instance of a C structure or C++ class which has been implemented as a mapped type.

Parameters:
Returns:

a non-zero value if the object can be converted.
int sipCanConvertToType(PyObject *obj, const sipTypeDef *td, int flags)

This checks if a Python object can be converted to an instance of a C structure, C++ class or mapped type.

Parameters:
Returns:

a non-zero value if the object can be converted.
sipCFunctionDef

New in version 4.19.

This C structure is used with sipGetCFunction() and encapsulates the components parts of a Python C function. The structure elements are as follows.

PyMethodDef *cf_function

The C function.

PyObject *cf_self

The optional bound object.

PyObject *sipClassName(PyObject *obj)

Deprecated since version 4.8: Use the following instead:

PyString_FromString(obj->ob_type->tp_name)

This gets the class name of a wrapped instance as a Python string. It comes with a reference.

Parameters:
  • obj – the wrapped instance.
Returns:

the name of the instance’s class.
PyObject *sipConvertFromConstVoidPtr(const void *cpp)

This creates a sip.voidptr object for a memory address. The object will not be writeable and has no associated size.

Parameters:
  • cpp – the memory address.
Returns:

the sip.voidptr object.
PyObject *sipConvertFromConstVoidPtrAndSize(const void *cpp, SIP_SSIZE_T size)

This creates a sip.voidptr object for a memory address. The object will not be writeable and can be used as an immutable buffer object.

Parameters:
  • cpp – the memory address.
  • size – the size associated with the address.
Returns:

the sip.voidptr object.
PyObject *sipConvertFromEnum(int eval, const sipTypeDef *td)

This converts a named C/C++ enum to an instance of the corresponding generated Python type.

Parameters:
Returns:

the Python object.
PyObject *sipConvertFromInstance(void *cpp, sipWrapperType *type, PyObject *transferObj)

Deprecated since version 4.8: Use sipConvertFromType() instead.

This converts a C structure or a C++ class instance to an instance of the corresponding generated Python type.

Parameters:
  • cpp – the C/C++ instance.
  • type – the type’s generated type object.
  • transferObj – this controls the ownership of the returned value.
Returns:

the Python object.

If the C/C++ instance has already been wrapped then the result is a new reference to the existing class instance object.

If transferObj is NULL and the instance has already been wrapped then the ownership is unchanged.

If transferObj is NULL and the instance is newly wrapped then ownership will be with C/C++.

If transferObj is Py_None then ownership is transferred to Python via a call to sipTransferBack().

Otherwise ownership is transferred to C/C++ and the instance associated with transferObj via a call to sipTransferTo().

The Python type is influenced by any applicable %ConvertToSubClassCode code.

PyObject *sipConvertFromMappedType(void *cpp, const sipMappedType *mt, PyObject *transferObj)

Deprecated since version 4.8: Use sipConvertFromType() instead.

This converts a C structure or a C++ class instance wrapped as a mapped type to an instance of the corresponding generated Python type.

Parameters:
  • cpp – the C/C++ instance.
  • mt – the opaque structure returned by sipFindMappedType().
  • transferObj – this controls the ownership of the returned value.
Returns:

the Python object.

If transferObj is NULL then the ownership is unchanged.

If transferObj is Py_None then ownership is transferred to Python via a call to sipTransferBack().

Otherwise ownership is transferred to C/C++ and the instance associated with transferObj argument via a call to sipTransferTo().

PyObject *sipConvertFromNamedEnum(int eval, PyTypeObject *type)

Deprecated since version 4.8: Use sipConvertFromEnum() instead.

This converts a named C/C++ enum to an instance of the corresponding generated Python type.

Parameters:
Returns:

the Python object.
PyObject *sipConvertFromNewInstance(void *cpp, sipWrapperType *type, PyObject *transferObj)

Deprecated since version 4.8: Use sipConvertFromNewType() instead.

This converts a new C structure or a C++ class instance to an instance of the corresponding generated Python type.

Parameters:
  • cpp – the C/C++ instance.
  • type – the type’s generated type object.
  • transferObj – this controls the ownership of the returned value.
Returns:

the Python object.

If transferObj is NULL or Py_None then ownership will be with Python.

Otherwise ownership will be with C/C++ and the instance associated with transferObj.

The Python type is influenced by any applicable %ConvertToSubClassCode code.

PyObject *sipConvertFromNewPyType(void *cpp, PyTypeObject *py_type, sipWrapper *owner, sipSimpleWrapper **selfp, const char *format, …)

New in version 4.15.

This converts a new C structure or a C++ class instance to an instance of a corresponding Python type (as opposed to the corresponding generated Python type). This is useful when the C/C++ library provides some sort of mechanism whereby handwritten code has some control over the exact type of structure or class being created. Typically it would be used to create an instance of the generated derived class which would then allow Python re-implementations of C++ virtual methods to function properly.

Parameters:
  • cpp – the C/C++ instance.
  • py_type – the Python type object. This is called to create the Python object and is passed the arguments defined by the string of format characters.
  • owner – is the optional owner of the Python object.
  • selfp – is an optional pointer to the sipPySelf instance variable of the C/C++ instance if that instance’s type is a generated derived class. Otherwise it should be NULL.
  • format – the string of format characters (see sipBuildResult()).
Returns:

the Python object. If there was an error then NULL is returned and a Python exception is raised.
PyObject *sipConvertFromNewType(void *cpp, const sipTypeDef *td, PyObject *transferObj)

This converts a new C structure or a C++ class instance to an instance of the corresponding generated Python type.

Parameters:
  • cpp – the C/C++ instance.
  • td – the type’s generated type structure.
  • transferObj – this controls the ownership of the returned value.
Returns:

the Python object.

If transferObj is NULL or Py_None then ownership will be with Python.

Otherwise ownership will be with C/C++ and the instance associated with transferObj.

The Python type is influenced by any applicable %ConvertToSubClassCode code.

SIP_SSIZE_T sipConvertFromSequenceIndex(SIP_SSIZE_T idx, SIP_SSIZE_T len)

This converts a Python sequence index (i.e. where a negative value refers to the offset from the end of the sequence) to a C/C++ array index. If the index was out of range then a negative value is returned and a Python exception raised.

Parameters:
  • idx – the sequence index.
  • len – the length of the sequence.
Returns:

the unsigned array index.
int sipConvertFromSliceObject(PyObject *slice, SIP_SSIZE_T length, SIP_SSIZE_T *start, SIP_SSIZE_T *stop, SIP_SSIZE_T *step, SIP_SSIZE_T *slicelength)

This is a thin wrapper around the Python PySlice_GetIndicesEx() function provided to make it easier to write handwritten code that is compatible with SIP v3.x and versions of Python earlier that v2.3.

PyObject *sipConvertFromType(void *cpp, const sipTypeDef *td, PyObject *transferObj)

This converts a C structure or a C++ class instance to an instance of the corresponding generated Python type.

Parameters:
  • cpp – the C/C++ instance.
  • td – the type’s generated type structure.
  • transferObj – this controls the ownership of the returned value.
Returns:

the Python object.

If the C/C++ instance has already been wrapped then the result is a new reference to the existing object.

If transferObj is NULL and the instance has already been wrapped then the ownership is unchanged.

If transferObj is NULL and the instance is newly wrapped then ownership will be with C/C++.

If transferObj is Py_None then ownership is transferred to Python via a call to sipTransferBack().

Otherwise ownership is transferred to C/C++ and the instance associated with transferObj via a call to sipTransferTo().

The Python class is influenced by any applicable %ConvertToSubClassCode code.

PyObject *sipConvertFromVoidPtr(void *cpp)

This creates a sip.voidptr object for a memory address. The object will be writeable but has no associated size.

Parameters:
  • cpp – the memory address.
Returns:

the sip.voidptr object.
PyObject *sipConvertFromVoidPtrAndSize(void *cpp, SIP_SSIZE_T size)

This creates a sip.voidptr object for a memory address. The object will be writeable and can be used as a mutable buffer object.

Parameters:
  • cpp – the memory address.
  • size – the size associated with the address.
Returns:

the sip.voidptr object.
PyObject *sipConvertToArray(void *data, const char *format, SIP_SSIZE_T len, int flags)

New in version 4.15.

This converts a one dimensional array of fundamental types to a sip.array object.

An array is very like a Python memoryview object. The underlying memory is not copied and may be modified in situ. Arrays support the buffer protocol and so can be passed to other modules, again without the underlying memory being copied.

sip.array objects are not supported by the sip code generator. They can only be created by handwritten code or by sip.voidptr.asarray().

Parameters:
  • data – the address of the start of the C/C++ array.
  • format – the format, as defined by the struct module, of an array element. At the moment only b (char), B (unsigned char), h (short), H (unsigned short), i (int), I (unsigned int), f (float) and d (double) are supported.
  • len – the number of elements in the array.
  • readonly – is non-zero if the array is read-only.
  • flags – any combination of the SIP_READ_ONLY and SIP_OWNS_MEMORY flags.
Returns:

the sip.array object.
void *sipConvertToInstance(PyObject *obj, sipWrapperType *type, PyObject *transferObj, int flags, int *state, int *iserr)

Deprecated since version 4.8: Use sipConvertToType() instead.

This converts a Python object to an instance of a C structure or C++ class assuming that a previous call to sipCanConvertToInstance() has been successful.

Parameters:
  • obj – the Python object.
  • type – the type’s generated type object.
  • transferObj – this controls any ownership changes to obj.
  • flags – any combination of the SIP_NOT_NONE and SIP_NO_CONVERTORS flags.
  • state – the state of the returned C/C++ instance is returned via this pointer.
  • iserr – the error flag is passed and updated via this pointer.
Returns:

the C/C++ instance.

If transferObj is NULL then the ownership is unchanged.

If transferObj is Py_None then ownership is transferred to Python via a call to sipTransferBack().

Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to sipTransferTo().

If state is not NULL then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any %ConvertToTypeCode. The calling code must then release the value at some point to prevent a memory leak by calling sipReleaseInstance().

If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn’t attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

void *sipConvertToMappedType(PyObject *obj, const sipMappedType *mt, PyObject *transferObj, int flags, int *state, int *iserr)

Deprecated since version 4.8: Use sipConvertToType() instead.

This converts a Python object to an instance of a C structure or C++ class that is implemented as a mapped type assuming that a previous call to sipCanConvertToMappedType() has been successful.

Parameters:
  • obj – the Python object.
  • mt – the opaque structure returned by sipFindMappedType().
  • transferObj – this controls any ownership changes to obj.
  • flags – this may be the SIP_NOT_NONE flag.
  • state – the state of the returned C/C++ instance is returned via this pointer.
  • iserr – the error flag is passed and updated via this pointer.
Returns:

the C/C++ instance.

If transferObj is NULL then the ownership is unchanged.

If transferObj is Py_None then ownership is transferred to Python via a call to sipTransferBack().

Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to sipTransferTo().

If state is not NULL then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any %ConvertToTypeCode. The calling code must then release the value at some point to prevent a memory leak by calling sipReleaseMappedType().

If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn’t attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

void *sipConvertToType(PyObject *obj, const sipTypeDef *td, PyObject *transferObj, int flags, int *state, int *iserr)

This converts a Python object to an instance of a C structure, C++ class or mapped type assuming that a previous call to sipCanConvertToType() has been successful.

Parameters:
  • obj – the Python object.
  • td – the type’s generated type structure.
  • transferObj – this controls any ownership changes to obj.
  • flags – any combination of the SIP_NOT_NONE and SIP_NO_CONVERTORS flags.
  • state – the state of the returned C/C++ instance is returned via this pointer.
  • iserr – the error flag is passed and updated via this pointer.
Returns:

the C/C++ instance.

If transferObj is NULL then the ownership is unchanged. If it is Py_None then ownership is transferred to Python via a call to sipTransferBack().

Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to sipTransferTo().

Note that obj can also be managed by the C/C++ instance itself, but this can only be achieved by using sipTransferTo().

If state is not NULL then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any %ConvertToTypeCode. The calling code must then release the value at some point to prevent a memory leak by calling sipReleaseType().

If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn’t attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

PyObject *sipConvertToTypedArray(void *data, const sipTypeDef *td, const char *format, size_t stride, SIP_SSIZE_T len, int flags)

New in version 4.15.

This converts a one dimensional array of instances of a C structure, C++ class or mapped type to a sip.array object.

An array is very like a Python memoryview object but it’s elements correspond to C structures or C++ classes. The underlying memory is not copied and may be modified in situ. Arrays support the buffer protocol and so can be passed to other modules, again without the underlying memory being copied.

sip.array objects are not supported by the sip code generator. They can only be created by handwritten code.

Parameters:
  • data – the address of the start of the C/C++ array.
  • td – an element’s type’s generated type structure.
  • format – the format, as defined by the struct module, of an array element.
  • stride – the size of an array element, including any padding.
  • len – the number of elements in the array.
  • flags – the optional SIP_READ_ONLY flag.
Returns:

the sip.array object.
void *sipConvertToVoidPtr(PyObject *obj)

This converts a Python object to a memory address. PyErr_Occurred() must be used to determine if the conversion was successful.

Parameters:
  • obj – the Python object which may be Py_None, a sip.voidptr or a PyCObject.
Returns:

the memory address.
sipDateDef

New in version 4.19.

This C structure is used with sipGetDate(), sipFromDate(), :c:func:`sipGetDateTime() and sipFromDateTime() and encapsulates the components parts of a Python date. The structure elements are as follows.

int pd_year

The year.

int pd_month

The month (1-12).

int pd_day

The day (1-31).

int sipEnableAutoconversion(const sipTypeDef *td, int enable)

New in version 4.14.7.

Instances of some classes may be automatically converted to other Python objects even though the class has been wrapped. This allows that behaviour to be suppressed so that an instances of the wrapped class is returned instead.

Parameters:
  • td – the type’s generated type structure. This must refer to a class.
  • enable – is non-zero if auto-conversion should be enabled for the type. This is the default behaviour.
Returns:

1 or 0 depending on whether or not auto-conversion was previously enabled for the type. This allows the previous state to be restored later on. -1 is returned, and a Python exception raised, if there was an error.
int sipEnableGC(int enable)

New in version 4.19.1.

This enables or disables the Python garbarge collector.

Parameters:
  • enable – is greater than 0 if the garbage collector should be enabled.
Returns:

1 or 0 depending on whether or not the garbage collector was previously enabled. This allows the previous state to be restored later on. -1 is returned if there was an error.
int sipExportSymbol(const char *name, void *sym)

Python does not allow extension modules to directly access symbols in another extension module. This exports a symbol, referenced by a name, that can subsequently be imported, using sipImportSymbol(), by another module.

Parameters:
  • name – the name of the symbol.
  • sym – the value of the symbol.
Returns:

0 if there was no error. A negative value is returned if name is already associated with a symbol or there was some other error.
sipWrapperType *sipFindClass(const char *type)

Deprecated since version 4.8: Use sipFindType() instead.

This returns a pointer to the generated type object corresponding to a C/C++ type.

Parameters:
  • type – the C/C++ declaration of the type.
Returns:

the generated type object. This will not change and may be saved in a static cache. NULL is returned if the C/C++ type doesn’t exist.
const sipMappedType *sipFindMappedType(const char *type)

Deprecated since version 4.8: Use sipFindType() instead.

This returns a pointer to an opaque structure describing a mapped type.

Parameters:
  • type – the C/C++ declaration of the type.
Returns:

the opaque structure. This will not change and may be saved in a static cache. NULL is returned if the C/C++ type doesn’t exist.
PyTypeObject *sipFindNamedEnum(const char *type)

Deprecated since version 4.8: Use sipFindType() instead.

This returns a pointer to the generated Python type object corresponding to a named C/C++ enum.

Parameters:
  • type – the C/C++ declaration of the enum.
Returns:

the generated Python type object. This will not change and may be saved in a static cache. NULL is returned if the C/C++ enum doesn’t exist.
const sipTypeDef *sipFindType(const char *type)

This returns a pointer to the generated type structure corresponding to a C/C++ type.

Parameters:
  • type – the C/C++ declaration of the type.
Returns:

the generated type structure. This will not change and may be saved in a static cache. NULL is returned if the C/C++ type doesn’t exist.
void *sipForceConvertToInstance(PyObject *obj, sipWrapperType *type, PyObject *transferObj, int flags, int *state, int *iserr)

Deprecated since version 4.8: Use sipForceConvertToType() instead.

This converts a Python object to an instance of a C structure or C++ class by calling sipCanConvertToInstance() and, if it is successfull, calling sipConvertToInstance().

See sipConvertToInstance() for a full description of the arguments.

void *sipForceConvertToMappedType(PyObject *obj, const sipMappedType *mt, PyObject *transferObj, int flags, int *state, int *iserr)

Deprecated since version 4.8: Use sipForceConvertToType() instead.

This converts a Python object to an instance of a C structure or C++ class which has been implemented as a mapped type by calling sipCanConvertToMappedType() and, if it is successfull, calling sipConvertToMappedType().

See sipConvertToMappedType() for a full description of the arguments.

void *sipForceConvertToType(PyObject *obj, const sipTypeDef *td, PyObject *transferObj, int flags, int *state, int *iserr)

This converts a Python object to an instance of a C structure, C++ class or mapped type by calling sipCanConvertToType() and, if it is successfull, calling sipConvertToType().

See sipConvertToType() for a full description of the arguments.

void sipFree(void *mem)

This returns an area of memory allocated by sipMalloc() to the heap.

Parameters:
  • mem – the memory address.
PyObject *sipFromDate(const sipDateDef *date)

New in version 4.19.

This creates a Python date object from its component parts.

Parameters:
  • date – the component parts of the date.
Returns:

the Python date object.
PyObject *sipFromDateTime(const sipDateDef *date, const sipTimeDef *time)

New in version 4.19.

This creates a Python datetime object from its component parts.

Parameters:
  • date – the date related component parts of the datetime.
  • time – the time related component parts of the datetime.
Returns:

the Python datetime object.
PyObject *sipFromMethod(const sipMethodDef *method)

New in version 4.19.

This creates a Python method object from its component parts.

Parameters:
  • method – the component parts of the method.
Returns:

the Python method object.
PyObject *sipFromTime(const sipTimeDef *time)

New in version 4.19.

This creates a Python time object from its component parts.

Parameters:
  • time – the component parts of the time.
Returns:

the Python time object.
void *sipGetAddress(sipSimpleWrapper *obj)

New in version 4.12.

This returns the address of the C structure or C++ class instance wrapped by a Python object.

Parameters:
  • obj – the Python object.
Returns:

the address of the C/C++ instance
int sipGetBufferInfo(PyObject *obj, sipBufferInfoDef *buffer_info)

New in version 4.19.

This checks to see if an object implements the Python buffer protocol and, if so, optionally returns the buffer information. It is similar to PyObject_GetBuffer() and should be used instead of that when the limited Python API is enabled. Note that, at the moment, only 1-dimensional buffers are supported.

Parameters:
  • obj – the Python object.
  • buffer_info – if this is not NULL, and the object implements the buffer protocol, then the buffer information is returned in this structure. There should be a corresponding call to sipReleaseBuffer().
Returns:

> 0 if the object supports the buffer protocol and the buffer information was returned (if requested). 0 if the object does not support the buffer protocol. < 0 (and a Python exception is raised) if the object supports the buffer protocol but there was an error returning the requested buffer information.
int sipGetCFunction(PyObject *obj, sipCFunctionDef *c_function)

New in version 4.19.

This checks to see if an object is a Python C function object and, if so, optionally returns its component parts.

Parameters:
  • obj – the Python object.
  • c_function – if this is not NULL, and the object is a C function object, then the component parts are returned in this structure.
Returns:

a non-zero value if the object is a Python C function object.
int sipGetDate(PyObject *obj, sipDateDef *date)

New in version 4.19.

This checks to see if an object is a Python date object and, if so, optionally returns its component parts.

Parameters:
  • obj – the Python object.
  • date – if this is not NULL, and the object is a date object, then the component parts are returned in this structure.
Returns:

a non-zero value if the object is a Python date object.
int sipGetDateTime(PyObject *obj, sipDateDef *date, sipTimeDef *time)

New in version 4.19.

This checks to see if an object is a Python datetime object and, if so, optionally returns its component parts.

Parameters:
  • obj – the Python object.
  • date – if this is not NULL, and the object is a datetime object, then the date related component parts are returned in this structure.
  • time – if this is not NULL, and the object is a datetime object, then the time related component parts are returned in this structure.
Returns:

a non-zero value if the object is a Python datetime object.
struct _frame sipGetFrame(int depth)

New in version 4.19.

This retrieves a frame object from the current execution stack.

Parameters:
  • depth – the depth of frame to retrieve where 0 is the current frame, 1 is the previous frame etc.
Returns:

the opaque frame or NULL if there wasn’t one at the given depth.
void sipInstanceDestroyed(sipSimpleWrapper *obj)

New in version 4.19.3.

This should be called by handwritten code if it is able to detect that a wrapped C++ instance has been destroyed from C++. It should not be called if SIP is able to detect this itself, i.e. when the instance was created from Python and the class has a virtual destructor.

Parameters:
  • obj – the Python object that wraps the destroyed instance.
PyInterpreterState *sipGetInterpreter()

New in version 4.17.1.

This returns the address of the Python interpreter. If it is NULL then calls to the Python interpreter library must not be made.

Returns:the address of the Python interpreter
int sipGetMethod(PyObject *obj, sipMethodDef *method)

New in version 4.19.

This checks to see if an object is a Python method object and, if so, optionally returns its component parts.

Parameters:
  • obj – the Python object.
  • method – if this is not NULL, and the object is a method object, then the component parts are returned in this structure.
Returns:

a non-zero value if the object is a Python method object.
void *sipGetMixinAddress(sipSimpleWrapper *obj, const sipTypeDef *td)

New in version 4.15.

This returns the address of the C++ class instance that implements the mixin of a wrapped Python object.

Parameters:
Returns:

the address of the C++ instance
PyObject *sipGetPyObject(void *cppptr, const sipTypeDef *td)

This returns a borrowed reference to the Python object for a C structure or C++ class instance.

Parameters:
Returns:

the Python object or NULL (and no exception is raised) if the C/C++ instance hasn’t been wrapped.
int sipGetState(PyObject *transferObj)

The %ConvertToTypeCode directive requires that the provided code returns an int describing the state of the converted value. The state usually depends on any transfers of ownership that have been requested. This is a convenience function that returns the correct state when the converted value is a temporary.

Parameters:
  • transferObj – the object that describes the requested transfer of ownership.
Returns:

the state of the converted value.
int sipGetTime(PyObject *obj, sipTimeDef *time)

New in version 4.19.

This checks to see if an object is a Python time object and, if so, optionally returns its component parts.

Parameters:
  • obj – the Python object.
  • time – if this is not NULL, and the object is a time object, then the component parts are returned in this structure.
Returns:

a non-zero value if the object is a Python time object.
void *sipGetTypeUserData(const sipWrapperType *type)

New in version 4.19.

Each generated type corresponding to a wrapped C/C++ type, or a user sub-class of such a type, contains a pointer for the use of handwritten code. This returns the value of that pointer.

Parameters:
  • type – the type object.
Returns:

the type-specific pointer.
PyObject *sipGetUserObject(const sipSimpleWrapper *obj)

New in version 4.19.

Each wrapped object can contain a reference to a single Python object that can be used for any purpose by handwritten code and will automatically be garbage collected at the appropriate time. This returns that object.

Parameters:
  • obj – the wrapped object.
Returns:

the user object.
PyObject *sipGetWrapper(void *cppptr, sipWrapperType *type)

Deprecated since version 4.8: Use sipGetPyObject() instead.

This returns a borrowed reference to the wrapped instance object for a C structure or C++ class instance.

Parameters:
  • cppptr – the pointer to the C/C++ instance.
  • type – the generated type object corresponding to the C/C++ type.
Returns:

the Python object or NULL (and no exception is raised) if the C/C++ instance hasn’t been wrapped.
void *sipImportSymbol(const char *name)

Python does not allow extension modules to directly access symbols in another extension module. This imports a symbol, referenced by a name, that has previously been exported, using sipExportSymbol(), by another module.

Parameters:
  • name – the name of the symbol.
Returns:

the value of the symbol. NULL is returned if there is no such symbol.
sipIntTypeClassMap

Deprecated since version 4.8.

This C structure is used with sipMapIntToClass() to define a mapping between integer based RTTI and generated type objects. The structure elements are as follows.

int typeInt

The integer RTTI.

sipWrapperType **pyType.

A pointer to the corresponding generated type object.

int sipIsAPIEnabled(const char *name, int from, int to)

New in version 4.9.

This checks to see if the current version number of an API falls within a given range. See Managing Incompatible APIs for more detail.

Parameters:
  • name – the name of the API.
  • from – the lower bound of the range. For the API to be enabled its version number must be greater than or equal to from. If from is 0 then this check isn’t made.
  • to – the upper bound of the range. For the API to be enabled its version number must be less than to. If to is 0 then this check isn’t made.
Returns:

a non-zero value if the API is enabled.
int sipIsUserType(const sipWrapperType *type)

New in version 4.19.

This checks if a type corresponds to a wrapped C/C++ type or a user sub-class of such a type.

Parameters:
  • type – the type object.
Returns:

a non-zero value if the type is a user defined type.
unsigned long sipLong_AsUnsignedLong(PyObject *obj)

This function is a thin wrapper around PyLong_AsUnsignedLong() that works around a bug in Python v2.3.x and earlier when converting integer objects.

void *sipMalloc(size_t nbytes)

This allocates an area of memory on the heap using the Python PyMem_Malloc() function. The memory is freed by calling sipFree().

Parameters:
  • nbytes – the number of bytes to allocate.
Returns:

the memory address. If there was an error then NULL is returned and a Python exception raised.
sipWrapperType *sipMapIntToClass(int type, const sipIntTypeClassMap *map, int maplen)

Deprecated since version 4.8.

This can be used in %ConvertToSubClassCode code as a convenient way of converting integer based RTTI to the corresponding generated type object.

Parameters:
  • type – the integer RTTI.
  • map – the table of known RTTI and the corresponding type objects (see sipIntTypeClassMap). The entries in the table must be sorted in ascending order of RTTI.
  • maplen – the number of entries in the table.
Returns:

the corresponding type object, or NULL if type wasn’t in map.
sipWrapperType *sipMapStringToClass(char *type, const sipStringTypeClassMap *map, int maplen)

Deprecated since version 4.8.

This can be used in %ConvertToSubClassCode code as a convenient way of converting '\0' terminated string based RTTI to the corresponding generated type object.

Parameters:
  • type – the string RTTI.
  • map – the table of known RTTI and the corresponding type objects (see sipStringTypeClassMap). The entries in the table must be sorted in ascending order of RTTI.
  • maplen – the number of entries in the table.
Returns:

the corresponding type object, or NULL if type wasn’t in map.
sipMethodDef

New in version 4.19.

This C structure is used with sipGetMethod() and sipFromMethod() and encapsulates the components parts of a Python method. The structure elements are as follows.

PyObject *pm_function

The function that implements the method.

PyObject *pm_self

The bound object.

PyObject *pm_class

The class. (Python v2 only.)

sipNewUserTypeFunc sipSetNewUserTypeHandler(const sipTypeDef *td, sipNewUserTypeFunc handler)

New in version 4.19.

The allows a function to be specified that is called whenever a user defined sub-class of a C/C++ type is created (i.e. one implemented in Python). It is normalled called from a module’s %PostInitialisationCode. It is provided as an alternative to providing a meta-type when the limited Python API is enabled.

Parameters:
  • td – the generated type object corresponding to the C/C++ type.
  • handler – the function that is called whenever a user defined sub-class of the type is created. The function takes a single argument which is the sipWrapperType of the user defined class. It returns an int which is 0 if there was no error. A Python exception is raised and -1 returned if there was an error.
Returns:

the previously installed handler. This allows handlers to be chained.
int sipParseResult(int *iserr, PyObject *method, PyObject *result, const char *format, …)

This converts a Python object (usually returned by a method) to C/C++ based on a format string and associated values in a similar way to the Python PyArg_ParseTuple() function.

Parameters:
  • iserr – if this is not NULL then the location it points to is set to a non-zero value if there was an error.
  • method – the Python method that returned result.
  • result – the Python object returned by method.
  • format – the format string.
Returns:

0 if there was no error. Otherwise a negative value is returned, and an exception raised.

This is normally called by handwritten code specified with the %VirtualCatcherCode directive with method being the supplied sipMethod and result being the value returned by sipCallMethod().

If format begins and ends with parentheses then result must be a Python tuple and the rest of format is applied to the tuple contents.

In the following description the first letter is the format character, the entry in parentheses is the Python object type that the format character will convert, and the entry in brackets are the types of the C/C++ values to be passed.

ae (object) [char *]
Convert a Python string-like object of length 1 to a C/C++ char according to the encoding e. e can either be A for ASCII, L for Latin-1, or 8 for UTF-8. For Python v2 the object may be either a string or a unicode object that can be encoded. For Python v3 the object may either be a bytes object or a string object that can be encoded. An object that supports the buffer protocol may also be used.
b (integer) [bool *]
Convert a Python integer to a C/C++ bool.
c (string/bytes) [char *]
Convert a Python v2 string object or a Python v3 bytes object of length 1 to a C/C++ char.
d (float) [double *]
Convert a Python floating point number to a C/C++ double.
e (integer) [enum *]
Convert a Python integer to an anonymous C/C++ enum.
f (float) [float *]
Convert a Python floating point number to a C/C++ float.
g (string/bytes) [const char **, SIP_SSIZE_T *]
Convert a Python v2 string object or a Python v3 bytes object to a C/C++ character array and its length. If the Python object is Py_None then the array and length are NULL and zero respectively.
h (integer) [short *]
Convert a Python integer to a C/C++ short.
i (integer) [int *]
Convert a Python integer to a C/C++ int.
l (long) [long *]
Convert a Python long to a C/C++ long.
m (long) [unsigned long *]
Convert a Python long to a C/C++ unsigned long.
n (long) [long long *]
Convert a Python long to a C/C++ long long.
o (long) [unsigned long long *]
Convert a Python long to a C/C++ unsigned long long.
s (string/bytes) [const char **]

Deprecated since version 4.8: Use B instead.

Convert a Python v2 string object or a Python v3 bytes object to a C/C++ '\0' terminated string. If the Python object is Py_None then the string is NULL.

t (long) [unsigned short *]
Convert a Python long to a C/C++ unsigned short.
u (long) [unsigned int *]
Convert a Python long to a C/C++ unsigned int.
w (unicode/string) [wchar_t *]
Convert a Python v2 string or unicode object or a Python v3 string object of length 1 to a C/C++ wide character.
x (unicode/string) [wchar_t **]
Convert a Python v2 string or unicode object or a Python v3 string object to a C/C++ L'\0' terminated wide character string. If the Python object is Py_None then the string is NULL.
Ae (object) [int, const char **]
Convert a Python string-like object to a C/C++ '\0' terminated string according to the encoding e. e can either be A for ASCII, L for Latin-1, or 8 for UTF-8. If the Python object is Py_None then the string is NULL. The integer uniquely identifies the object in the context defined by the S format character and allows an extra reference to the object to be kept to ensure that the string remains valid. For Python v2 the object may be either a string or a unicode object that can be encoded. For Python v3 the object may either be a bytes object or a string object that can be encoded. An object that supports the buffer protocol may also be used.
B (string/bytes) [int, const char **]
Convert a Python v2 string object or a Python v3 bytes object to a C/C++ '\0' terminated string. If the Python object is Py_None then the string is NULL. The integer uniquely identifies the object in the context defined by the S format character and allows an extra reference to the object to be kept to ensure that the string remains valid.
Cf (wrapped class) [sipWrapperType *, int *, void **]

Deprecated since version 4.8: Use Hf instead.

Convert a Python object to a C structure or a C++ class instance and return its state as described in sipConvertToInstance(). f is a combination of the following flags encoded as an ASCII character by adding 0 to the combined value:

0x01 disallows the conversion of Py_None to NULL

0x02 implements the Factory and TransferBack
annotations
0x04 suppresses the return of the state of the returned C/C++
instance. Note that the int * used to return the state is not passed if this flag is specified.
Df (wrapped instance) [const sipTypeDef *, int *, void **]

Deprecated since version 4.10.1: Use Hf instead.

Convert a Python object to a C structure, C++ class or mapped type instance and return its state as described in sipConvertToType(). f is a combination of the following flags encoded as an ASCII character by adding 0 to the combined value:

0x01 disallows the conversion of Py_None to NULL

0x02 implements the Factory and TransferBack
annotations
0x04 suppresses the return of the state of the returned C/C++
instance. Note that the int * used to return the state is not passed if this flag is specified.
E (wrapped enum) [PyTypeObject *, enum *]

Deprecated since version 4.8: Use F instead.

Convert a Python named enum type to the corresponding C/C++ enum.

F (wrapped enum) [sipTypeDef *, enum *]
Convert a Python named enum type to the corresponding C/C++ enum.
G (unicode/string) [wchar_t **, SIP_SSIZE_T *]
Convert a Python v2 string or unicode object or a Python v3 string object to a C/C++ wide character array and its length. If the Python object is Py_None then the array and length are NULL and zero respectively.
Hf (wrapped instance) [const sipTypeDef *, int *, void **]

Convert a Python object to a C structure, C++ class or mapped type instance as described in sipConvertToType(). f is a combination of the following flags encoded as an ASCII character by adding 0 to the combined value:

0x01 disallows the conversion of Py_None to NULL

0x02 implements the Factory and TransferBack
annotations

0x04 returns a copy of the C/C++ instance.

L (integer) [signed char *]

New in version 4.12.

Convert a Python integer to a C/C++ signed char.

M (long) [unsigned char *]

New in version 4.12.

Convert a Python long to a C/C++ unsigned char.

N (object) [PyTypeObject *, PyObject **]
A Python object is checked to see if it is a certain type and then returned without any conversions. The reference count is incremented. The Python object may be Py_None.
O (object) [PyObject **]
A Python object is returned without any conversions. The reference count is incremented.
S [sipSimpleWrapper *]
This format character, if used, must be the first. It is used with other format characters to define a context and doesn’t itself convert an argument.
T (object) [PyTypeObject *, PyObject **]
A Python object is checked to see if it is a certain type and then returned without any conversions. The reference count is incremented. The Python object may not be Py_None.
V (sip.voidptr) [void **]
Convert a Python sip.voidptr object to a C/C++ void *.
z (object) [const char *, void **]

New in version 4.14.1.

Convert a Python named capsule object to a C/C++ void *.

Z (object) []
Check that a Python object is Py_None. No value is returned.
! (object) [PyObject **]

New in version 4.14.1.

A Python object is checked to see if it implements the buffer protocol and then returned without any conversions. The reference count is incremented. The Python object may not be Py_None.

$ (object) [PyObject **]

New in version 4.14.1.

A Python object is checked to see if it implements the buffer protocol and then returned without any conversions. The reference count is incremented. The Python object may be Py_None.

PyObject *sipPyTypeDict(const PyTypeObject *py_type)

New in version 4.19.

This provides access to a Python type object’s tp_dict field and is typically used when the limited Python API is enabled.

Parameters:
  • py_type – the type object.
Returns:

the value of the type object’s tp_dict field.
const char *sipPyTypeName(const PyTypeObject *py_type)

New in version 4.19.

This provides access to a Python type object’s tp_name field and is typically used when the limited Python API is enabled.

Parameters:
  • py_type – the type object.
Returns:

the value of the type object’s tp_name field.
int sipRegisterAttributeGetter(const sipTypeDef *td, sipAttrGetterFunc getter)

This registers a handler that will called just before SIP needs to get an attribute from a wrapped type’s dictionary for the first time. The handler must then populate the type’s dictionary with any lazy attributes.

Parameters:
  • td – the optional generated type structure that determines which types the handler will be called for.
  • getter – the handler function.
Returns:

0 if there was no error, otherwise -1 is returned.

If td is not NULL then the handler will only be called for types with that type or that are sub-classed from it. Otherwise the handler will be called for all types.

A handler has the following signature.

int handler(const sipTypeDef *td, PyObject *dict)

td is the generated type definition of the type whose dictionary is to be populated.

dict is the dictionary to be populated.

0 is returned if there was no error, otherwise -1 is returned.

See the section Lazy Type Attributes for more details.

int sipRegisterProxyResolver(const sipTypeDef *td, sipProxyResolverFunc resolver)

New in version 4.15.

This registers a resolver that will called just before SIP wraps a C/C++ pointer in a Python object. The resolver may choose to replace the C/C++ pointer with the address of another object. Typically this is used to replace a proxy by the object that is being proxied for.

Parameters:
  • td – the optional generated type structure that determines which type the resolver will be called for.
  • resolver – the resolver function.
Returns:

0 if there was no error, otherwise -1 is returned.

A resolver has the following signature.

void *resolver(void *proxy)

proxy is C/C++ pointer that is being wrapped.

The C/C++ pointer that will actually be wrapped is returned.

int sipRegisterPyType(PyTypeObject *type)

This registers a Python type object that can be used as the meta-type or super-type of a wrapped C++ type.

Parameters:
  • type – the type object.
Returns:

0 if there was no error, otherwise -1 is returned.

See the section Types and Meta-types for more details.

void sipReleaseBufferInfo(sipBufferInfoDef *buffer_info)

New in version 4.19.

This releases the buffer information related to a Python object that implements the buffer protocol that was created with a corresponding call to sipGetBufferInfo(). It is similar to PyBuffer_Release() and should be used instead of that when the limited Python API is enabled.

Parameters:
  • buffer_info – the buffer information to release.
void sipReleaseInstance(void *cpp, sipWrapperType *type, int state)

Deprecated since version 4.8: Use sipReleaseType() instead.

This destroys a wrapped C/C++ instance if it was a temporary instance. It is called after a call to either sipConvertToInstance() or sipForceConvertToInstance().

Parameters:
  • cpp – the C/C++ instance.
  • type – the type’s generated type object.
  • state – describes the state of the C/C++ instance.
void sipReleaseMappedType(void *cpp, const sipMappedType *mt, int state)

Deprecated since version 4.8: Use sipReleaseType() instead.

This destroys a wrapped C/C++ mapped type if it was a temporary instance. It is called after a call to either sipConvertToMappedType() or sipForceConvertToMappedType().

Parameters:
  • cpp – the C/C++ instance.
  • mt – the opaque structure returned by sipFindMappedType().
  • state – describes the state of the C/C++ instance.
void sipReleaseType(void *cpp, const sipTypeDef *td, int state)

This destroys a wrapped C/C++ or mapped type instance if it was a temporary instance. It is called after a call to either sipConvertToType() or sipForceConvertToType().

Parameters:
  • cpp – the C/C++ instance.
  • td – the type’s generated type structure.
  • state – describes the state of the C/C++ instance.
const char *sipResolveTypedef(const char *name)

This returns the value of a C/C++ typedef.

Parameters:
  • name – the name of the typedef.
Returns:

the value of the typedef or NULL if there was no such typedef.
void sipSetDestroyOnExit(int destroy)

New in version 4.14.7.

When the Python interpreter exits it garbage collects those objects that it can. This means that any corresponding C++ instances and C structures owned by Python are destroyed. Unfortunately this happens in an unpredictable order and so can cause memory faults within the wrapped library. Calling this function with a value of zero disables the automatic destruction of C++ instances and C structures.

Parameters:
  • destroy – non-zero if all C++ instances and C structures owned by Python should be destroyed when the interpreter exits. This is the default.
void sipSetTypeUserData(sipWrapperType *type, void *data)

New in version 4.19.

Each generated type corresponding to a wrapped C/C++ type, or a user sub-class of such a type, contains a pointer for the use of handwritten code. This sets the value of that pointer.

Parameters:
  • type – the type object.
  • data – the type-specific pointer.
void sipSetUserObject(sipSimpleWrapper *obj, PyObject *user)

New in version 4.19.

Each wrapped object can contain a reference to a single Python object that can be used for any purpose by handwritten code and will automatically be garbage collected at the appropriate time. This sets that object.

Parameters:
  • obj – the wrapped object.
  • user – the user object.
sipSimpleWrapper

This is a C structure that represents a Python wrapped instance whose type is sip.simplewrapper. It is an extension of the PyObject structure and so may be safely cast to it.

When the limited Python API is enabled and Python v3.2 or later is being used then it is only available as an opaque (i.e. incomplete) type and the following members are not available.

void *data

This is initialised to the address of the C/C++ instance. If an access function is subsequently provided then it may be used for any purpose by the access function.

sipAccessFunc access_func

This is the address of an optional access function that is called, with a pointer to this structure as its first argument. If its second argument is UnguardedPointer then it returns the address of the C/C++ instance, even if it is known that its value is no longer valid. If the second argument is GuardedPointer then it returns the address of the C++ instance or 0 if it is known to be invalid. If the second argument is ReleaseGuard then the structure is being deallocated and any dynamic resources used by the access function should be released. If there is no access function then the sipSimpleWrapper.data is used as the address of the C/C++ instance. Typically a custom meta-type is used to set an access method after the Python object has been created.

PyObject *user

This can be used for any purpose by handwritten code and will automatically be garbage collected at the appropriate time.

PyTypeObject *sipSimpleWrapper_Type

This is the type of a sipSimpleWrapper structure and is the C implementation of sip.simplewrapper. It may be safely cast to sipWrapperType.

When the limited Python API is enabled and Python v3.2 or later is being used then it is only available as an opaque (i.e. incomplete) type.

sipStringTypeClassMap

Deprecated since version 4.8.

This C structure is used with sipMapStringToClass() to define a mapping between '\0' terminated string based RTTI and Generated Type Objects. The structure elements are as follows.

char *typeString

The '\0' terminated string RTTI.

sipWrapperType **pyType.

A pointer to the corresponding generated type object.

sipTimeDef

New in version 4.19.

This C structure is used with sipGetTime(), sipFromTime(), :c:func:`sipGetDateTime() and sipFromDateTime() and encapsulates the components parts of a Python time. The structure elements are as follows.

int pt_hour

The hour (0-23).

int pt_minute

The minute (0-59).

int pt_second

The second (0-59).

int pt_microsecond

The microsecond (0-999999).

void sipTransferBack(PyObject *obj)

This transfers ownership of a Python wrapped instance to Python (see Ownership of Objects).

Parameters:
  • obj – the wrapped instance.

In addition, any association of the instance with regard to the cyclic garbage collector with another instance is removed.

void sipTransferBreak(PyObject *obj)

Any association of a Python wrapped instance with regard to the cyclic garbage collector with another instance is removed. Ownership of the instance should be with C++.

Parameters:
  • obj – the wrapped instance.

Deprecated since version 4.14: Use the following instead:

sipTransferTo(obj, NULL);
void sipTransferTo(PyObject *obj, PyObject *owner)

This transfers ownership of a Python wrapped instance to C++ (see Ownership of Objects).

Parameters:
  • obj – the wrapped instance.
  • owner – an optional wrapped instance that obj becomes associated with with regard to the cyclic garbage collector. If owner is NULL then no such association is made. If owner is Py_None then obj is given an extra reference which is removed when the C++ instance’s destructor is called. If owner is the same value as obj then any reference cycles involving obj can never be detected or broken by the cyclic garbage collector. Responsibility for calling the C++ instance’s destructor is always transfered to C++.
PyTypeObject *sipTypeAsPyTypeObject(const sipTypeDef *td)

This returns a pointer to the Python type object that SIP creates for a generated type structure.

Parameters:
  • td – the type structure.
Returns:

the Python type object. If the type structure refers to a mapped type then NULL will be returned.

If the type structure refers to a C structure or C++ class then the Python type object may be safely cast to a sipWrapperType.

const sipTypeDef *sipTypeFromPyTypeObject(PyTypeObject *py_type)

This returns the generated type structure for a Python type object.

Parameters:
  • py_type – the Python type object.
Returns:

the type structure or NULL if the Python type object doesn’t correspond to a type structure.
int sipTypeIsClass(sipTypeDef *td)

This checks if a generated type structure refers to a C structure or C++ class.

Parameters:
  • td – the type structure.
Returns:

a non-zero value if the type structure refers to a structure or class.
int sipTypeIsEnum(sipTypeDef *td)

This checks if a generated type structure refers to a named enum.

Parameters:
  • td – the type structure.
Returns:

a non-zero value if the type structure refers to an enum.
int sipTypeIsMapped(sipTypeDef *td)

This checks if a generated type structure refers to a mapped type.

Parameters:
  • td – the type structure.
Returns:

a non-zero value if the type structure refers to a mapped type.
int sipTypeIsNamespace(sipTypeDef *td)

This checks if a generated type structure refers to a C++ namespace.

Parameters:
  • td – the type structure.
Returns:

a non-zero value if the type structure refers to a namespace.
const char *sipTypeName(const sipTypeDef *td)

This returns the C/C++ name of a wrapped type.

Parameters:
Returns:

the name of the C/C++ type.
const sipTypeDef *sipTypeScope(const sipTypeDef *td)

This returns the generated type structure of the enclosing scope of another generated type structure.

Parameters:
  • td – the type structure.
Returns:

the type structure of the scope or NULL if the type has no scope.
void *sipUnicodeData(PyObject *obj, int *char_size, SIP_SSIZE_T *len)

New in version 4.19.

This returns information about the contents of a Python unicode object.

This is only supported for Python v3.3 and later.

Parameters:
  • obj – the unicode object.
  • char_size – a pointer which will be updated with the number of bytes (either 1, 2 or 4) used to store a character. If there was an error then this will be a negative value.
  • len – a pointer which will be updated with the number of characters (not bytes) in the unicode object.
Returns:

the address of the buffer where the characters are stored. It will be undefined if the returned character size is a negative value.
PyObject *sipUnicodeNew(SIP_SSIZE_T len, unsigned maxchar, int *kind, void **data)

New in version 4.19.

This creates a Python unicode object that will hold a set number of characters, each character being of a certain size.

This is only supported for Python v3.3 and later.

Parameters:
  • len – the number of characters.
  • maxchar – the largest code point that will be placed in the object.
  • kind – a pointer which will be updated with a value that represents the number of bytes (either 1, 2 or 4) used to store a character.
  • data – a pointer which will be updated with the address of the buffer where the characters will be stored.
Returns:

the unicode object or NULL if there was an error.
void sipUnicodeWrite(int kind, void *data, int index, unsigned value)

New in version 4.19.

This updates the buffer of a Python unicode object with a character at a particular position.

This is only supported for Python v3.3 and later.

Parameters:
  • kind – the value that represents the number of bytes (either 1, 2 or 4) used to store a character.
  • data – the address of the buffer where the characters are stored.
  • index – the character (not byte) index of the character to be updated.
  • value – the value of the new character.
PyTypeObject *sipVoidPtr_Type

This is the type of a PyObject structure that is used to wrap a void *.

sipWrapper

This is a C structure that represents a Python wrapped instance whose type is sip.wrapper. It is an extension of the sipSimpleWrapper and PyObject structures and so may be safely cast to both.

When the limited Python API is enabled and Python v3.2 or later is being used then it is only available as an opaque (i.e. incomplete) type.

int sipWrapper_Check(PyObject *obj)

Deprecated since version 4.8: Use the following instead:

PyObject_TypeCheck(obj, sipWrapper_Type)

This checks if a Python object is a wrapped instance.

Parameters:
  • obj – the Python object.
Returns:

a non-zero value if the Python object is a wrapped instance.
PyTypeObject *sipWrapper_Type

This is the type of a sipWrapper structure and is the C implementation of sip.wrapper. It may be safely cast to sipWrapperType.

sipWrapperType

This is a C structure that represents a SIP generated type object. It is an extension of the PyTypeObject structure (which is itself an extension of the PyObject structure) and so may be safely cast to PyTypeObject (and PyObject).

When the limited Python API is enabled and Python v3.2 or later is being used then it is only available as an opaque (i.e. incomplete) type.

PyTypeObject *sipWrapperType_Type

This is the type of a sipWrapperType structure and is the C implementation of sip.wrappertype.

Event Handlers

New in version 4.19.3.

The sip module will trigger a number of events. Handwritten code can supply handlers for these events to allow it to perform additional actions. Each event has a type, described by the sipEventType enum. An event handler is registered using sipRegisterEventHandler(). The signature of an event handler is specific to the event type.

enum sipEventType

This is the enum that defines the different event types.

int sipRegisterEventHandler(sipEventType type, const sipTypeDef *td, void *handler)

This registers an event handler which will be called whenever an event is triggered.

Parameters:
  • type – the event type for which the handler is registered.
  • td – the generated type structure - the handler will only be invoked for Python object corresponding to this type or a sub-type.
  • handler – the handler that is called when the event is triggered.
Returns:

0 if there was no error, otherwise -1 is returned (and a Python exception is raised).

Generated Type Structures

SIP generates an opaque type structure for each C structure, C++ class, C++ namespace, named enum or mapped type being wrapped. These are sipTypeDef structures and are used extensively by the SIP API.

The names of these structure are prefixed by sipType_.

For those structures that correspond to C structures, C++ classes, C++ namespaces or named enums the remaining part of the name is the fully qualified name of the structure, class, namespace or enum name. Any :: scope separators are replaced by an underscore. For example, the type object for class Klass is sipType_Klass.

For those structure that correspond to mapped types the remaining part of the name is generated by SIP. The only way for handwritten code to obtain a pointer to a structure for a mapped type is to use sipFindType().

The type structures of all imported types explicitly used by a module are available to handwritten code.

Generated Type Objects

Deprecated since version 4.8: Use the corresponding generated type structure (see Generated Type Structures) and sipTypeAsPyTypeObject() instead.

SIP generates a sipWrapperType type object for each C structure or C++ class being wrapped.

These objects are named with the structure or class name prefixed by sipClass_. For example, the type object for class Klass is sipClass_Klass.

Generated Named Enum Type Objects

Deprecated since version 4.8: Use the corresponding generated type structure (see Generated Type Structures) and sipTypeAsPyTypeObject() instead.

SIP generates a type object for each named enum being wrapped. These are PyTypeObject structures. (Anonymous enums are wrapped as Python integers.)

These objects are named with the fully qualified enum name (i.e. including any enclosing scope) prefixed by sipEnum_. For example, the type object for enum Enum defined in class Klass is sipEnum_Klass_Enum.

Generated Derived Classes

For most C++ classes being wrapped SIP generates a derived class with the same name prefixed by sip. For example, the derived class for class Klass is sipKlass.

If a C++ class doesn’t have any virtual or protected methods in it or any of it’s super-class hierarchy, or does not emit any Qt signals, then a derived class is not generated.

Most of the time handwritten code should ignore the derived classes. The only exception is that handwritten constructor code specified using the %MethodCode directive should call the derived class’s constructor (which has the same C++ signature) rather then the wrapped class’s constructor.

Generated Exception Objects

SIP generates a Python object for each exception defined with the %Exception directive.

These objects are named with the fully qualified exception name (i.e. including any enclosing scope) prefixed by sipException_. For example, the type object for enum Except defined in class Klass is sipException_Klass_Except.

The objects of all imported exceptions are available to handwritten code.