I have got very simple script :
import bpy
bpy.ops.object.select_all(action='SELECT')
bpy.context.object.show_wire = True
bpy.data.objects["Lamp"].show_wire = True
bpy.data.objects["Camera"].show_wire = True
bpy.data.objects["Suzanne.001"].show_wire = True
What i need is that ["Suzanne.001"] will not be specified but rather be something universal for ALL objects in scene, is there something similar like ["all_objects"] or something like that ?