memoryview

I am converting a Cython memoryview to a numpy array (to be able to use it in pure Python code): from libc.stdlib cimport realloc cimport numpy as np DTYPE = np.float64 ctypedef np.float64_t DTYPE_t cpdef np.ndarray[DTYPE_t] compute(DTYPE_t[:,::1] data): cdef unsigned int Nchannels = data.shape[0] cdef unsigned int Ndata = data.shape[1] cdef DTYPE_t* output = NULL cdef DTYPE_t[::1] mv output = <DTYPE_t*>realloc(output, Ndata*sizeof(output)) if not output: raise MemoryError() mv = <DTYPE_t[:Ndata]>output mv[10:Ndata-10] = 0.0 # various calculations... return np.asarray(mv, dtype=DTYPE, order='C

This question already has an answer here: What exactly is the point of memoryview in Python 5 answers The full description of memoryview can be found here : Create a memoryview that references obj . obj must support the buffer protocol. Built-in objects that support the buffer protocol include bytes and bytearray . A memoryview has the notion of an element , which is the atomic memory unit handled by the originating object obj . For many simple types such as bytes and bytearray , an element is a single byte, but other types such as array.array may have bigger elements. A memoryview is