topic Re: How to Delete NULL Records in Python Questions

How to Delete NULL Records

H_A_D_Padmasiri — Mon, 07 Apr 2014 10:20:56 GMT

Dear Sir

I want to update "CNT_PT_ID" field & delete the NULL records ("CNT_PT_ID" is NULL). I wrote a python script.When it runs "CNT_PT_ID" is update correctly. But "CNT_PT_ID" = "Null" records not deleted. No error message display. Can you give me a help to correct it.

Thanks

Padmasiri

Re: How to Delete NULL Records

WilliamCraft — Mon, 07 Apr 2014 10:28:03 GMT

Try changing CNT_PT_ID" = "Null" to be "CNT_PT_ID" IS NULL instead. Does that work?

Re: How to Delete NULL Records

H_A_D_Padmasiri — Tue, 08 Apr 2014 03:04:26 GMT

Try changing CNT_PT_ID" = "Null" to be "CNT_PT_ID" IS NULL instead. Does that work?

No it does not work it gives following error
Traceback (most recent call last):
File "J:\Gampaha\Scripts\Script1.py", line 109, in <module>
if row.CNT_PT_ID is NULL:
NameError: name 'NULL' is not defined

Failed to execute (LISTool1.0).

Thanks

Re: How to Delete NULL Records

benberman — Sun, 12 Dec 2021 07:29:00 GMT

It should look something like this:

cur = arcpy.UpdateCursor("CNT_Anno")
for row in cur:
        val1 = row.getValue("Some attribute field")
        if val1.isdigit():
                if int(val1) >= 9000:
                        row.setValue("CNT_PT_ID", int(val1))
                        cur.updateRow(row)
        if row.isNull("CNT_PT_ID")==True:
                cur.deleteRow(row)
del cur
del row

you may also be able to get away with deleting the isdigit() line.

Re: How to Delete NULL Records

Zeke — Tue, 08 Apr 2014 11:19:21 GMT

Python also often uses None instead of Null.

Re: How to Delete NULL Records

MathewCoyle — Sun, 12 Dec 2021 07:29:03 GMT

Give this a try.

layer = r'CNT_Anno'
cur = arcpy.da.UpdateCursor(layer, ['TextString', 'CNT_PT_ID'])
for row in cur:
    if row[0]:
        try:
            if int(row[0]) >= 9000:
                row[1] = int(row[0])
                cur.updateRow(row)
        except:
            pass
    if row[1] is None:
        cur.deleteRow()

Re: How to Delete NULL Records

H_A_D_Padmasiri — Sun, 12 Dec 2021 07:29:06 GMT

It should look something like this:

cur = arcpy.UpdateCursor("CNT_Anno")
for row in cur:
        val1 = row.getValue("Some attribute field")
        if val1.isdigit():
                if int(val1) >= 9000:
                        row.setValue("CNT_PT_ID", int(val1))
                        cur.updateRow(row)
        if row.isNull("CNT_PT_ID")==True:
                cur.deleteRow(row)
del cur
del row

you may also be able to get away with deleting the isdigit() line.

Dear FLBB

It gives me Following Error

Traceback (most recent call last):
File "J:\Gampaha\Scripts\Script1.py", line 109, in <module>
if row.isNULL("CNT_PT_ID")==True:
File "c:\program files\arcgis\desktop10.1\arcpy\arcpy\arcobjects\_base.py", line 28, in __getattr__
raise AttributeError("%s" % attr)
AttributeError: isNULL

Failed to execute (LISTool1.0).
Thanks

Re: How to Delete NULL Records

benberman — Wed, 09 Apr 2014 08:10:48 GMT

Dear FLBB

It gives me Following Error

Traceback (most recent call last):
File "J:\Gampaha\Scripts\Script1.py", line 109, in <module>
if row.isNULL("CNT_PT_ID")==True:
File "c:\program files\arcgis\desktop10.1\arcpy\arcpy\arcobjects\_base.py", line 28, in __getattr__
raise AttributeError("%s" % attr)
AttributeError: isNULL

Failed to execute (LISTool1.0).
Thanks

You typed "isNULL". You need to be typing "isNull". Case sensitivity very important in python.

Re: How to Delete NULL Records

AhmedEl-Sisi — Sun, 12 Dec 2021 07:29:09 GMT

This approach should work for you

if not row.CNT_PT_ID :
        cur.deleteRow(row)