concatenate where one field may be null

Discussion created by phoffman35 on Oct 18, 2011
Latest reply on Oct 18, 2011 by phoffman35
I am trying to run this script and where I am conactenating a first name and a lastname with a space inbetween. What is happening is that if the first name is null I get a blank space in front for the owner name. I am using a file geodatabase.
I have left out the other code that is not needed for this exaple.

Here is my code that runs w/o error but puts a space in front for null firstname.

RPT_PARCELS_OWNER_DATA_with_OwnerName_Field = "C:\\Application Database\\RPTSA.gdb\\RPT_PARCELS_OWNER_DATA"

gp.CalculateField_management(RPT_PARCELS_OWNER_DATA_with_OwnerName_Field, "OwnerName", "[FIRST_NAME] +\" \"+ [LAST_NAME]", "VB", "")

I have tried an expression and a codeblock but I get error message.

Here is my try:

expression = 'concat(!FIRST_NAME!,!LAST_NAME!)'
codeBlock = \
    "def concat(first,last):\
    if first == '':\
    return !LAST_NAME!\
    return !FIRST_NAME! + ' ' + !LAST_NAME!"

gp.CalculateField_management(RPT_PARCELS_OWNER_DATA_with_OwnerName_Field, "OwnerName", expression, "PYTHON", codeBlock)
The error message says the parameters are not valid.
Thanks for help, I am a novice at python.