Sum Selected Rooms

# -*- coding: utf-8 -*-
__title__ = "03.04 - Sum Rooms"
__doc__ = """Date    = 02.01.2023
_____________________________________________________________________
Description:
Tool to Sum selected Rooms.
If no rooms selected, you will be asked to select them.
_____________________________________________________________________
Author: Erik Frits"""

# ╦╔╦╗╔═╗╔═╗╦═╗╔╦╗╔═╗
# ║║║║╠═╝║ ║╠╦╝ ║ ╚═╗
# ╩╩ ╩╩  ╚═╝╩╚═ ╩ ╚═╝ IMPORTS
#==================================================
from Autodesk.Revit.DB import *
from Autodesk.Revit.DB.Architecture import Room
from Autodesk.Revit.UI.Selection import ObjectType, PickBoxStyle, Selection

# CUstom
from Snippets._selection import ISelectionFilter_Classes
from Snippets._convert import convert_internal_units

# .NET Imports
import clr
clr.AddReference("System")
from System.Collections.Generic import List

# ╦  ╦╔═╗╦═╗╦╔═╗╔╗ ╦  ╔═╗╔═╗
# ╚╗╔╝╠═╣╠╦╝║╠═╣╠╩╗║  ║╣ ╚═╗
#  ╚╝ ╩ ╩╩╚═╩╩ ╩╚═╝╩═╝╚═╝╚═╝ VARIABLES
#==================================================
uidoc = __revit__.ActiveUIDocument
doc   = __revit__.ActiveUIDocument.Document

selection = uidoc.Selection # type: Selection

# ╔╦╗╔═╗╦╔╗╔
# ║║║╠═╣║║║║
# ╩ ╩╩ ╩╩╝╚╝
#==================================================

# GET ROOMS
selected_elements = [doc.GetElement(e_id) for e_id in selection.GetElementIds()]
selected_rooms    = [el for el in selected_elements if type(el) == Room]

if not selected_rooms:
    filter_types     = ISelectionFilter_Classes([Room])
    ref_picked_rooms = selection.PickObjects(ObjectType.Element, filter_types)
    selected_rooms   = [doc.GetElement(ref) for ref in ref_picked_rooms]

if not selected_rooms:
    print('There were no Rooms selected. Please Try Again.')
    import sys
    sys.exit()

# GET VALUES
total = 0
total_b = 0
for room in selected_rooms:
    room_name = room.get_Parameter(BuiltInParameter.ROOM_NAME).AsString()
    area_m2         = convert_internal_units(room.Area, get_internal=False, units='m2')
    area_m2_rounded = round(area_m2, 2)

    total   += area_m2_rounded
    print("{}: {}m²".format(room_name, area_m2_rounded))

# PRINT RESULTS
print('-'*20)
print("Total: {}m²".format( total))
print('Selected {} Rooms.'.format(len(selected_rooms)))