Marshalling of numpy.ndarray (Python world) with System.Array (.NET world)

DotNetMarshalling.py

"""
Helper module for marshalling Python types with .NET types
"""
import numpy
import ctypes
import clr, System
clr.AddReference("System.Runtime")
clr.AddReference("System.Runtime.Numerics")

## Marshalling NumPy <==> .NET
def ToDotNetArray(npArray: numpy.ndarray) -> System.Array:
#{
    """
    PURPOSE:

        Converts a NumPy array to a .NET array.

    SYNOPSIS:

        netArray = ToDotNetArray(npArray)

    INPUTS:

        'npArray': The NumPy array to convert

    OUTPUT:

        'netArray': Resulting .NET array

    REMARKS:

        Adapted from PythonNet discussions:

            - https://github.com/pythonnet/pythonnet/issues/514
            - https://github.com/pythonnet/pythonnet/issues/652
            - https://gist.github.com/robbmcleod/73ca42da5984e6d0e5b6ad28bc4a504e
    """
    NP2NET = {
        numpy.dtype(numpy.complex128) : System.Numerics.Complex, # NP.Complex(double) => NET.Complex(double)
        numpy.dtype(numpy.complex64) : System.Numerics.Complex, # NP.Complex(float) => NET.Complex(double)
        numpy.dtype(numpy.float64) : System.Double,
        numpy.dtype(numpy.float32) : System.Single,
        numpy.dtype(numpy.int64) : System.Int64,
        numpy.dtype(numpy.int32) : System.Int32,
        numpy.dtype(numpy.int16) : System.Int16,
        numpy.dtype(numpy.int8) : System.SByte,
        numpy.dtype(numpy.uint64) : System.UInt64,
        numpy.dtype(numpy.uint32) : System.UInt32,
        numpy.dtype(numpy.uint16) : System.UInt16,
        numpy.dtype(numpy.uint8) : System.Byte,
        numpy.dtype(numpy.bool) : System.Boolean,
    }

    if (npArray.dtype == numpy.dtype('complex64')): npArray = npArray.astype(numpy.dtype('complex128'))
    if (not npArray.flags.c_contiguous or not npArray.flags.aligned): npArray = numpy.ascontiguousarray(npArray)
    assert npArray.flags.c_contiguous

    try: netArray = System.Array.CreateInstance(NP2NET[npArray.dtype], *(npArray.shape))
    except KeyError: raise NotImplementedError("Numpy arrays of type {} are yet not supported.".format(npArray.dtype))

    try:
        destHandle = System.Runtime.InteropServices.GCHandle.Alloc(netArray, System.Runtime.InteropServices.GCHandleType.Pinned)
        sourcePtr = npArray.__array_interface__['data'][0]
        destPtr = destHandle.AddrOfPinnedObject().ToInt64()
        ctypes.memmove(destPtr, sourcePtr, npArray.nbytes)
    finally:
        if (destHandle.IsAllocated): destHandle.Free()

    return netArray
#}
def FromDotNetArray(netArray: System.Array) -> numpy.ndarray: 
#{
    """
    PURPOSE:

        Converts a .NET array to a NumPy array.

    SYNOPSIS:

        npArray = FromDotNetArray(netArray)

    INPUTS:

        'netArray': The .NET array to convert

    OUTPUT:

        'nptArray': Resulting NumPy array

    REMARKS:

        Adapted from PythonNet discussions:

            - https://github.com/pythonnet/pythonnet/issues/514
            - https://github.com/pythonnet/pythonnet/issues/652
            - https://gist.github.com/robbmcleod/73ca42da5984e6d0e5b6ad28bc4a504e
    """     
    NET2NP = {
        "System.Numerics.Complex" : numpy.dtype(numpy.complex128),
        "System.Double" : numpy.dtype(numpy.float64),
        "System.Single" : numpy.dtype(numpy.float32),
        "System.Int64" : numpy.dtype(numpy.int64),
        "System.Int32" : numpy.dtype(numpy.int32),
        "System.Int16" : numpy.dtype(numpy.int16),
        "System.SByte" : numpy.dtype(numpy.int8),
        "System.UInt64" : numpy.dtype(numpy.uint64), 
        "System.UInt32" : numpy.dtype(numpy.uint32),
        "System.UInt16" : numpy.dtype(numpy.uint16),
        "System.Byte" : numpy.dtype(numpy.uint8),
        "System.Boolean" : numpy.dtype(numpy.bool),
    }

    dims = numpy.empty(netArray.Rank, dtype=int)
    for i in range(netArray.Rank): dims[i] = netArray.GetLength(i)

    netElementType = netArray.GetType().GetElementType().FullName
    try: npArray = numpy.empty(dims, order='C', dtype=NET2NP[netElementType])
    except KeyError: raise NotImplementedError(f'Net arrays of type {netElementType} are yet not supported.')

    try:
        sourceHandle = System.Runtime.InteropServices.GCHandle.Alloc(netArray, System.Runtime.InteropServices.GCHandleType.Pinned)
        sourcePtr = sourceHandle.AddrOfPinnedObject().ToInt64()
        destPtr = npArray.__array_interface__['data'][0]
        ctypes.memmove(destPtr, sourcePtr, npArray.nbytes)
    finally:
        if sourceHandle.IsAllocated: sourceHandle.Free()

    return npArray
#}

Adapted from: https://gist.github.com/robbmcleod/73ca42da5984e6d0e5b6ad28bc4a504e
Difference: Numpy Complex arrays (python) now directly marshall with System.Array (.NET) whose element type is System.Numerics.Complex

• First time I'm coding in python sorry if syntax is not so conventional ...