ArcPy script not finding empty values in Text fields?

Question

I have written a script that checks populated (or empty) values off of coded value and range domains. It works well with the range domains. It finds empty fields as well as values that are out of range for that field. It also works well when there are values in TEXT fields that don't conform to the accepted domain codes. However, it does not find NULL (None or "") values in TEXT fields.

Here's the code.

if ftype in txtList:  ##Start coded value domain checks
with arcpy.da.SearchCursor(tbl,['UID',fname,'QAQC_FLAG']) as cur:
    listValues = []  
    for row in cur:
        uid = row[0]
        fieldValue = row[1]
        if fieldValue == None or fieldValue == "":
            insRow = ["VNULL",fname,"","Value not populated with incoming data",uid]
            insCur.insertRow(insRow)
            msg = "Added row {0} to {1}.".format(insRow,qaTbl)
            arcpy.AddMessage(msg)

I can't figure out why it won't identify empty fields in the table. Some of these fields have ALL empty values and the script isn't identifying them.

Answer 1

Looks like it could be possible that instead of an empty string "", you may have whitespace (one or more spaces " " etc). Maybe test a little more implicitly for "empty" values:

isEmpty = lambda x: x is not None and str(x).strip() != ""

Then try that in your if statement:

with arcpy.da.SearchCursor(tbl,['UID',fname,'QAQC_FLAG']) as cur:
    listValues = []  
    for row in cur:
        uid = row[0]
        fieldValue = row[1]
        if isEmpty(fieldValue):
            insRow = ["VNULL",fname,"","Value not populated with incoming data",uid]
            # do stuff here

And as others have mentioned, the snippet is not actually doing anything after the if statement.