I'm trying to label parcels from a shapefile in the Python expression below in ArcGIS 10.2. All parcels should be labeled with the last 8 characters of their [PARCEL_NUM], and parcels 10 acres or greater should also include their [PROP_ADDRE]. [Acres] is a Double field.

Instead, all parcels get labeled with [PARCEL_NUM] and [PROP_ADDRE]. Using Maplex, land parcel placement. Any ideas on what's going wrong?

In response to comments, no, no errors verifying the expression. Tried switching to checking for [ACRES] < 10.0 first, no difference. Also, as noted above, [ACRES] is a Double data type. No Null values in any of the three fields.

def FindLabel ( [PARCEL_NUM], [PROP_ADDRE], [Acres]   ):
  if [Acres] >= 10.0:
    return [PARCEL_NUM][-8:] + '\n' + [PROP_ADDRE] 
    return [PARCEL_NUM][-8:]
  • Are you getting any errors when you verify the expression? – juturna May 19 '15 at 15:13
  • @recurvata What is the data type for the Acres field? – papadoo May 19 '15 at 15:42
  • Do you have any Null values in the Acres field? – juturna May 19 '15 at 15:48

Took me a few tries and some digging to realize but, as per the ArcGIS Help:

Note: To label a subset of features based on a field value, create the SQL query in the label class instead of through the label expression.

So try creating a label class for those features greater than or equal to 10 acres(SQL) then use the expression to format the label. enter image description here

  • That worked, but still not sure why it wouldn't work as straight python. What's the point of having advanced label expressions otherwise? Oh well, thanks. – recurvata May 19 '15 at 18:40
  • Ya I was stumped as well – landocalrissian May 19 '15 at 18:49

This is definitely possible. I just did a test, and I was able to get it to work by using float() around the Acres variable.

So, this worked fine for me:

def FindLabel([PARCEL_NUM], [PROP_ADDRE], [Acres]):
  if float([Acres]) >= 10.0:
    return [PARCEL_NUM][-8:] + '\n' + [PROP_ADDRE] 
    return [PARCEL_NUM][-8:]
  • 5
    @recurvata This is the correct solution. Per the help file on label expressions, "Field values are automatically cast to text strings. Therefore, if you wish to use a numeric value in an arithmetic operation, or when making a comparison, you will need to cast it back to a numeric data type." – Chris W May 19 '15 at 20:46

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