Old Buffer Protocol¶

This section describes the legacy buffer protocol, which has been introduced in Python 1.6. It is still supported but deprecated in the Python 2.x series. Python 3 introduces a new buffer protocol which fixes weaknesses and shortcomings of the protocol, and has been backported to Python 2.6. See Buffers and Memoryview Objects for more information.

int PyObject_AsCharBuffer(PyObject *obj, const char **buffer, Py_ssize_t *buffer_len)¶

Returns a pointer to a read-only memory location usable as character-based input. The obj argument must support the single-segment character buffer interface. On success, returns 0, sets buffer to the memory location and buffer_len to the buffer length. Returns -1 and sets a TypeError on error.

New in version 1.6.

Changed in version 2.5: This function used an int * type for buffer_len. This might require changes in your code for properly supporting 64-bit systems.

int PyObject_AsReadBuffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len)¶

Returns a pointer to a read-only memory location containing arbitrary data. The obj argument must support the single-segment readable buffer interface. On success, returns 0, sets buffer to the memory location and buffer_len to the buffer length. Returns -1 and sets a TypeError on error.

New in version 1.6.

Changed in version 2.5: This function used an int * type for buffer_len. This might require changes in your code for properly supporting 64-bit systems.

int PyObject_CheckReadBuffer(PyObject *o)¶

Returns 1 if o supports the single-segment readable buffer interface. Otherwise returns 0.

New in version 2.2.

int PyObject_AsWriteBuffer(PyObject *obj, void **buffer, Py_ssize_t *buffer_len)¶

Returns a pointer to a writeable memory location. The obj argument must support the single-segment, character buffer interface. On success, returns 0, sets buffer to the memory location and buffer_len to the buffer length. Returns -1 and sets a TypeError on error.

New in version 1.6.

Changed in version 2.5: This function used an int * type for buffer_len. This might require changes in your code for properly supporting 64-bit systems.