trying to update empty string field with a string

Question

I need to update a column of values such that empty fields are changed to the string "OFF_ROAD." I've looked up a plethora of examples, and this is what I'm trying to get to work, but when I run it, nothing happens to the input file-

import arcpy
from arcpy import env
env.overwriteOutput = True
arcpy.env.workspace = "F:/EMILY/TEST/GET_TYPE_TEST/"
infc = "SpJoinscript.shp"
cur = arcpy.UpdateCursor(infc) 
for row in cur:
if row.TYPE_1 == "": 
 row.TYPE_1 = "OFF_ROAD" 
cur.updateRow(row) 
del row
del cur
print "done mothaf"

what am I overlooking here???!!!

Answer 1

If the field is empty (or NULL), the thing to test is whether the field is None.

Try changing the if row.TYPE_1 == "": to if row.TYPE_1 is None:

Answer 2

I figured it out- I used a da.updateCursor with an SQL query- import arcpy

from arcpy import env
env.overwriteOutput = True
arcpy.env.workspace = "F:/EMILY/TEST/GET_TYPE_TEST/"
infc = "SpJoinscript.shp"
with arcpy.da.UpdateCursor(infc, "TYPE_1", "TYPE_1=''") as cursor:
 for row in cursor:
 row[0] = "OFF_ROAD"
 cursor.updateRow(row)