Connect Rig To Deform

import bpy

def connect_bones(from_armature, to_armature):
    armature_rig = bpy.data.objects[from_armature]
    armature_deform = bpy.data.objects[to_armature]

    rig_bones = [i for i in armature_rig.pose.bones]
    for rig_bone in rig_bones:
        deform_bone = armature_deform.pose.bones.get(rig_bone.name.replace("rig", "deform"))

        if not deform_bone:
            continue

        # remove deform contraints
        for con in deform_bone.constraints:
            deform_bone.constraints.remove(con)

        # create constraint
        copy_con = deform_bone.constraints.new('COPY_TRANSFORMS')
        copy_con.target = armature_rig
        copy_con.subtarget = rig_bone.name
        copy_con.target_space = 'POSE'
        copy_con.owner_space = 'POSE'

connect_bones('Rabbit_Rig', 'Rabbit_Deform')