Converting Julia arrays, views to NumPy arrays via PyCall

General Usage
,
8

Ok, here’s the self contained hack:

julia> using PyCall

julia> A = rand(Int, 256);

julia> pytypeof( PyObject(reinterpret(UInt64, A)) )
PyObject <class 'list'>

julia> pytypeof( PyObject(@view(A[1:100])) )
PyObject <class 'list'>

julia> module PyCallHack
           import PyCall: NpyArray, PYARR_TYPES, @npyinitialize, npy_api, npy_type
           import PyCall: @pycheck, NPY_ARRAY_ALIGNED, NPY_ARRAY_WRITEABLE, pyembed
           import PyCall: PyObject, PyPtr
           const HACKED_ARRAYS = Union{SubArray{T}, Base.ReinterpretArray{T}, Base.ReshapedArray{T}, Base.PermutedDimsArray{T}} where T <: PYARR_TYPES
           function NpyArray(a::HACKED_ARRAYS{T}, revdims::Bool) where T <: PYARR_TYPES
               @npyinitialize
               size_a = revdims ? reverse(size(a)) : size(a)
               strides_a = revdims ? reverse(strides(a)) : strides(a)
               p = @pycheck ccall(npy_api[:PyArray_New], PyPtr,
                   (PyPtr,Cint,Ptr{Int},Cint, Ptr{Int},Ptr{T}, Cint,Cint,PyPtr),
                   npy_api[:PyArray_Type],
                   ndims(a), Int[size_a...], npy_type(T),
                   Int[strides_a...] * sizeof(eltype(a)), a, sizeof(eltype(a)),
                   NPY_ARRAY_ALIGNED | NPY_ARRAY_WRITEABLE,
                   C_NULL)
              return PyObject(p, a)
           end
           pyembed(po::PyObject, jo::HACKED_ARRAYS) = pyembed(po, jo.parent)
       end
Main.PyCallHack

julia> pytypeof( PyObject(reinterpret(UInt64, A)) )
PyObject <class 'numpy.ndarray'>

julia> pytypeof( PyObject(@view(A[1:100])) )
PyObject <class 'numpy.ndarray'>
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