+
+from ctypes import (byref, POINTER, Structure, pythonapi,
+ c_int, c_char, c_char_p, c_void_p, py_object, c_ssize_t)
+import sys
+
+c_ssize_p = POINTER(c_ssize_t)
+
+PyObject_GetBuffer = pythonapi.PyObject_GetBuffer
+PyBuffer_Release = pythonapi.PyBuffer_Release
+
+
+PyBUF_SIMPLE = 0
+PyBUF_WRITABLE = 1
+
+
+class Py_buffer(Structure):
+ _fields_ = [
+ ("buf", c_void_p),
+ ("obj", py_object),
+ ("len", c_ssize_t),
+ ("itemsize", c_ssize_t),
+ ("readonly", c_int),
+ ("ndim", c_int),
+ ("format", c_char_p),
+ ("shape", c_ssize_p),
+ ("strides", c_ssize_p),
+ ("suboffsets", c_ssize_p),
+ ("internal", c_void_p)
+ ]
+
+ if sys.version_info[0] < 3:
+ _fields_.insert(-1, ("smalltable", c_ssize_t * 2))
+
+ @classmethod
+ def get_from(cls, obj, flags=PyBUF_SIMPLE):
+ buf = cls()
+ PyObject_GetBuffer(py_object(obj), byref(buf), flags)
+ return buf
+
+ def release(self):
+ PyBuffer_Release(byref(self))
+
+
+def get_buffer(obj, writable=False):
+ buf = Py_buffer.get_from(obj, PyBUF_WRITABLE if writable else PyBUF_SIMPLE)
+ try:
+ buffer_type = c_char * buf.len
+ return buffer_type.from_address(buf.buf)
+ finally:
+ buf.release()
+