How to select a line with specific numeric field value using an inline variable for UpdateCursor in ArcGIS 10.0

StephenMorreale — Thu, 20 Nov 2014 15:42:31 GMT

I'm currently away in a remote field station using Arc 10.0 and having a hard time using an inline variable substitution for a numeric field value. I am trying to use UpdateCursor to select only a specific line by designating a "POSITION" field = to a numeric value that I can increment each time I go through the for loop. When I use a number in the line, it works. However, I can't seem to get the right syntax to substitute the hard-coded number for a variable.

here's the section of code:

## Attempt to update the cursor, then get value, then setvalue using an inline variable for the desired Field value

## THIS does not work

stefile = "ste1.shp"

stefield = "POSITION"

steclus = "CLUSTER"

steac = "AC"

stevalue = 100

stepos = 22

Z = arcpy.UpdateCursor(stefile, '"POSITION" = stepos') # This needs to be changed eg; '"POSITION" = a memvar') ...and at end of loop memvar +=1

for row in Z:

print row.getValue(steclus)

memvar = row.getValue(steclus)

row.setValue(steac, stevalue)

Z.updateRow(row)

print row.getValue(steac)

del Z

del row

### HERE are the error messages

# Runtime error <type 'exceptions.RuntimeError'>: ERROR 999999:

# Error executing function.

# A column was specified that does not exist.

Am I simply using the wrong syntax? Or am I barking up the wrong tree?

Guidance and advice welcome. Thanks.

topic How to select a line with specific numeric field value using an inline variable for UpdateCursor in ArcGIS 10.0 in Python Questions

How to select a line with specific numeric field value using an inline variable for UpdateCursor in ArcGIS 10.0