Get the position of a bone in Blender in pose space

bone_co_pose_space.py

import bpy
from mathutils import *
C=bpy.context
D=bpy.data

def get_bone_co_pose_space(bone_name, tip_or_head):
  """Expects an active Armature object, and if run as main an empty object called "Empty" """
    name = bone_name
    C.object.data.show_axes = True
    
    bone = C.object.data.bones[name]
    
    Mtip = Matrix.Translation(bone.tail)
    Mhead = Matrix.Translation(bone.head)
    
    if tip_or_head.lower() == "tip":
        dest = Mtip
    elif tip_or_head.lower() == "head":
        dest = Mhead
        
    if bone.parent:    
        Mptip = Matrix.Translation(bone.parent.tail - bone.parent.head)
        #head and orientation of parent bone
        Mw  = bone.parent.matrix_local
        #grandfather orientation
        Mw *= bone.parent.matrix.to_4x4().inverted()
        #tip of parent bone
        Mw *= Mptip
        #back to orientation of parent bone
        Mw *= bone.parent.matrix.to_4x4()
        #tip of bone
        Mw *= dest
        #orientation of bone
        Mw *= bone.matrix.to_4x4()    
    else:
        Mw = bone.matrix_local
        Mw *= bone.matrix.to_4x4().inverted()
        Mw *= dest
        Mw *= bone.matrix.to_4x4()
        
    return Mw

if __name__ == "__main__":
    D.objects["Empty"].matrix_world = \
        get_bone_co_pose_space("Bone.001", "tip")

It will throw an error - AttributeError: bpy_prop "Bone.matrix_local" is read-only.

Fix =

temp =  bone.parent.matrix_local
Mw  =temp.copy()