6

I want to autoincrement values in a field within a Python script. I've done this using Field Calculator and the code referenced here. I tried using this code in the Python script below but it is not working. 

#Import modules
import os, sys
import arcpy

#Set variables
workspace = "D:\\GIS\\data.gdb"
arcpy.env.workspace = workspace
table_name = "data_table" 
field = "KEY_2" #Short integer field

#This is the function I want to use on my KEY_2 field
rec=0 
def autoIncrement(field): 
    global rec
    pStart = 10  
        pInterval = 2 
    if (rec == 0):  
        rec = pStart  
        return rec 
    else:  
        rec += pInterval  
        return rec

field = autoIncrement()

I get a TypeError when I run this code:

Traceback (most recent call last):
  File "C:\Python26\ArcGIS10.0\pythonwin\pywin\framework\scriptutils.py", line 312, in     RunScript
    exec codeObject in __main__.__dict__
  File "D:\Python\scratch\sc3.py", line 23, in <module>
   field = autoIncrement()
TypeError: autoIncrement() takes exactly 1 argument (0 given)

I've moved things around in the script a bit but have not yet gotten my field to populate. Anyone have a suggestion?

Here's my final code, based on blord-castillo's answer:

#Import modules
import os, sys
import arcpy

#Set variables
workspace = "D:\\GIS\\data.gdb"
arcpy.env.workspace = workspace
table_name = "data_table" 
field = "KEY_2" #I made this a text field
rec=0

def autoIncrement(pStart = 10,pInterval = 2): #Using default values instead of setting     inside function
    global rec
    if (rec == 0):  
        rec = pStart  
        return rec
    else:
        rec += pInterval
        return rec

incrementCursor = arcpy.UpdateCursor(table_name) #There is no guarantee of order here
for row in incrementCursor:
    row.setValue(field, str(autoIncrement()))
    incrementCursor.updateRow(row)

del incrementCursor
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Patty Jula
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3 Answers3

10

You should use a cursor instead of field calculation to achieve this.

import arcpy

#Set variables
rec=0
workspace = "D:\\GIS\\data.gdb"
arcpy.env.workspace = workspace
table_name = "data_table" 
field = "KEY_2" #Short integer field

cursor = arcpy.UpdateCursor(table_name) #There is no guarantee of order here
for row in cursor:
    row.setValue(field,autoIncrement())
    cursor.updateRow(row)

def autoIncrement(pStart=10,pInterval=2): #Using default values instead of setting inside function
    global rec
    if (rec == 0):  
        rec = pStart  
        return rec
    else:
        rec = rec + pInterval
        return rec
blord-castillo
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  • Cool, thank you very much, @blord-castillo. I'm posting my final code above as based on what you suggest. I just had to switch location of cursor and function, and define the rec variable. Thanks, again! – Patty Jula Apr 05 '13 at 21:51
6

Here's a simple auto incrementor that doesn't rely on global variables

def autoIncrement(start=0,step=1):
    i=start
    while 1:
        yield i
        i+=step

incrementCursor = arcpy.UpdateCursor(table_name) #There is no guarantee of order here
incrementer = autoIncrement(10,2)
for row in incrementCursor:
    row.setValue(field, incrementer.next()) #Note use of next method
    incrementCursor.updateRow(row)

Batteries included!!! Apparently this is already in the standard library...

import itertools

inc = itertools.count()
incrementCursor = arcpy.UpdateCursor(table_name) #There is no guarantee of order here
for row in incrementCursor:
    row.setValue(field, inc.next()) #Note use of next method
    incrementCursor.updateRow(row)
user2856
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0

Looks like an old thread BUT...

There is the ability to sort with the UpdateCursor. I used the following

incrementCursor = arcpy.UpdateCursor(table_name, "", "", "", "SORT FIELD")

user102566
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