objectType_enum_items = (('0','Cube',''),('1','Pyramid',''))
bpy.types.Scene.exmapleUI_obj_type = bpy.props.EnumProperty(items = objectType_enum_items )

# draw function inside your UI panel
def draw(self, context):
    layout = self.layout
    layout.label(text="Object Type")
    layout.prop(context.scene, 'exmapleUI_obj_type ', expand=True) # expand true make it from dropdown list into a toggle button