if ObjectIDVal in valueDict: for n in range (1,len(updateFieldsList)): updateRow= valueDict[ObjectIDVal][n-1] updateRows.updateRow(updateRow)
I came across this thread when searching for the tool I have used several times in the past. It can update data based on spatial relationships as well as others. There is some setup involved, but it will do the trick.
https://solutions.arcgis.com/shared/help/attribute-assistant/