How do I add multiple fields to a table in Model Builder ArcGIS 10.4?

Question

I am developing a new model for a population profile geoprocessing task. The first step sums a series of variables based on a simple point in polygon routine. I then want to add a new set of field names to the table to create some percentages using Calculate Field.

This is possible using 'Add Field' but I need to use the tool several times and it is cumbersome as I have a high number of fields to add in.

Is there a way to use an iterator to run Add Field?

much appreciated

Justin

JustinGleeson1 · Answer

After some different approaches to this I created a simple .py script that updates the table with all the fields I need. See below.

...............................

import arcpy 
from arcpy import env 
env.workspace = r"C:\X\X.gdb"

for PopSummary in arcpy.ListTables("*"): 
try: 
arcpy.AlterField_management(PopSummary, "Sum_Pop_T11", "", "TotalPop") 
arcpy.AlterField_management(PopSummary, "Sum_Pop_014T11", "", "Pop_014")
arcpy.AlterField_management(PopSummary, "Sum_Pop_1524T1", "", "Pop_1524")
except: 
pass

..............................

Lot's of other useful way of updating a table using the Fields Toolset within the script - Alter Field, Calculate Field etc

JustinGleeson2 · Answer

Thanks Darren, the Iterate Row Selection seems to be the way to go. I have set this up and it takes it's values from a table with the required parameters in Add Field. I still seem to be running into trouble with it though.

Would you have the Iterate Row Selection and Add Field working off a secondary Model within the main Model?

Thanks

Justin

bharold · Answer

A good pattern is to make a numpy array of typed data and use arcpy.da.ExtentTable to add the fields to your table.

The Python snippet would be in a Calculate Value model tool.  An example of syntax is in this GP sample:

http://www.arcgis.com/home/item.html?id=da9efbe1232f426ead182213f53c8cd8