I am trying to create a script that creates a new list of rasters by searching through the file names then using that new list to execute the weighted sum function in spatial analyst. I am having trouble with executing the weighted sum.

Here is my code and error messaage:

#Import System Modules
import arcpy
from arcpy import env
from arcpy.sa import *

#set environment setting
env.workspace = "E:/AlexandraOrrego/GIS_2017/RasterData/clipped.gdb"
arcpy.env.mask = "E:/AlexandraOrrego/GIS_2017/RasterData/forest_xcap"

#checks out ArcGIS Spatial Analyst extension license

#Runs through rasters and sums based on DCA
rasList = arcpy.ListRasters()

#initialize an empty list 
matchedRasters = []

for raster in rasList:
    outRasterName = raster[7:12]    
    if outRasterName.startswith('11004'):
        print outRasterName

#executes weighted sum for of all matchedRasters with using value field and 
given a weight of 1        
for raster in matchedRasters():
    WSumTableObj = WSTable([raster, "VALUE", 1])
    outWeightedSum = WeightedSum(WSumTableObj)  
    #Saves the output
    outWeightedSum.save("output folder")

Here is what is printed and my error message:

Runtime error 
Traceback (most recent call last):
  File "<string>", line 29, in <module>
TypeError: 'list' object is not callable

1 Answer 1


You need to remove the parenthesis in: for raster in matchedRasters():

Also you are creating a WSumTableObject for each raster. Arent you supposed to create one WSumTableObject containing all the rasters?

If so could you try replacing the last for block with:

#executes weighted sum for of all matchedRasters with using value field and given a weight of 1  
WSumTableObj = WSTable([[raster,"VALUE", 1] for raster in matchedRasters])
outWeightedSum = WeightedSum(WSumTableObj)
  • I have edited my code to your suggestion and the script worked perfectly. Suddenly after running other processes in arcmap none of my arcpy scripts will run. For example, I load the arcpy script file into the python window in arcmap and hit enter to run, arcmap seems to load for a few seconds then returns >>> with no output, error, message and no processes were run.
    – Allie
    Commented Jun 30, 2017 at 19:31

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