I was able to use your answer to the original question for parts of my calculation but now I'm running into an issue when trying to add up those parts. The goal is to multiply a field (scores) by a number inputted by the user (the weight) for six different fields, then sum those all together, and divide by another field. When I use the "+" symbol I believe it thinks I want to concatenate everything. I've tried using the sum function but get an error saying it can't sum strings. Here's my code.
# This script calculates the Composite Burden Score for each gas station in R3 using user-defined weights for the inputs.
# The Composite Burden Score is calculated by summing the weighted scores for SVI, Floodplain, Highway, Evacuation, Demand, and Supply and then dividing by the Community Resilience score.
from ntpath import join
import arcpy
from arcpy import env
from arcgis.gis import GIS
# Set Environments
env.workspace = arcpy.GetParameterAsText(0)
arcpy.env.overwriteOutput = True
env.extent = arcpy.GetParameterAsText(1)
# Set Parameters
# By default, each input is equally weighted at 1/6th (or 0.16666)
Gas_Stations = arcpy.GetParameterAsText(2)
SVI_weight = arcpy.GetParameterAsText(3) or 0.16666
Floodplain_weight = arcpy.GetParameterAsText(4) or 0.16666
Highway_weight = arcpy.GetParameterAsText(5) or 0.16666
Evacuation_weight = arcpy.GetParameterAsText(6) or 0.16666
Demand_weight = arcpy.GetParameterAsText(7) or 0.16666
Supply_weight = arcpy.GetParameterAsText(8) or 0.16666
Expression = (("!SVI_Score! * {}".format(float(SVI_weight))) + ("!Floodplain_Score! * {}".format(float(Floodplain_weight))) + ("!Highway_Score! * {}".format(float(Highway_weight))) + ("!Evacuation_Score! * {}".format(float(Evacuation_weight))) + ("!Demand_Score! * {}".format(float(Demand_weight))) + ("!Supply_Score! * {}".format(float(Supply_weight)))) / "!Resilience Score!"
# Calculated the Composite Burden Score
arcpy.CalculateField_management(Gas_Stations, "Composite_Burden_Score_Weight", Expression, "PYTHON")