topic Re: Make Unique Alphanumeric value in Python Questions

Make Unique Alphanumeric value

Bmohammad — Wed, 07 Oct 2020 09:19:09 GMT

Dear All,

I want to calculate one field from another field e.g I want AAA- [FieldName], I want that AA will be change and give unique value e.g

AAA-[FieldName]

AAB-[FieldName]

ACA-[FieldName]

.....

etc

Thanks and regards

Bilal Alam

Re: Make Unique Alphanumeric value

JoshuaBixby — Wed, 07 Oct 2020 12:32:51 GMT

Do you want the prefix to follow a pattern? I can't see what the pattern would be from the examples (AAA-, AAB-, ACA-) you provide. If you do want a pattern, is having the pattern applied based on ObjectID order sufficient or is there another order of the data you want the pattern applied to?

Re: Make Unique Alphanumeric value

Bmohammad — Wed, 07 Oct 2020 12:37:47 GMT

Actually I don't want any pattern. Only first letter will be constant e.g A and other will be random like AA or AB or CA etc.

Re: Make Unique Alphanumeric value

JoshuaBixby — Wed, 07 Oct 2020 13:03:08 GMT

You want unique values, but the first value will be A, which leaves only the 2nd and 3rd spots to change. Assuming your values are case insensitive, e.g., AAb is the same as AAB, you will run out of unique values after 676 records. Do you have less than 676 records?

Re: Make Unique Alphanumeric value

Anonymous User — Wed, 07 Oct 2020 23:36:00 GMT

Hi Bilal

Hopefully below code could provide help.

abc = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

for i in range(0,26):
for j in range(0,26):
print ('A{0}{1}-[FieldName]'.format(abc,abc))

Regards,

Bing

Re: Make Unique Alphanumeric value

Bmohammad — Thu, 08 Oct 2020 05:11:19 GMT

Yes I have less then 676 records

Re: Make Unique Alphanumeric value

JoshuaBixby — Thu, 08 Oct 2020 16:10:03 GMT

OK. Let us know if you need any more than what Bing Zheng provided.

Re: Make Unique Alphanumeric value

Bmohammad — Tue, 13 Oct 2020 08:34:03 GMT

Dear Bing

Thanks for your help this work well when I run simply but I need to use this in arcpy.UpdateCursor and in place of [FieldName]. I want to use the values from one of the field already available in data.

Regards

Bilal

Re: Make Unique Alphanumeric value

Anonymous User — Tue, 13 Oct 2020 11:01:49 GMT

Hi Bilal

Actually, if you want to use this list during the update process, I would like to suggest to put it in the dictionary.

for example.

abc = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

ind1 = 0

ind2 = 0

preStr= {}

for i in range(0,26):
for j in range(0,26):

preStr[ind] = 'A{0}{1}'.format(abc,abc)

ind1 = ind1 + 1

fc = "c:/data/base.gdb/roads"

field1 = "field1"

field2 = "field2"

cursor = arcpy.UpdateCursor(fc)

for row in cursor:

row.setValue(field2, preStr[ind2] + row.getValue(field1) * 3.0)

ind2 = ind2 + 1

cursor.updateRow(row)

Hopefully, it works for you.

Regards,

Bing

Re: Make Unique Alphanumeric value

JoshuaBixby — Tue, 13 Oct 2020 14:56:39 GMT

Can you elaborate on

I want to use the values from one of the field already available in data.

Do you have an existing field that is partially populated already? If so, do you want to use those values if they already exist but add new ones if they are missing? And, do you want to make sure any new values are not the same as existing values?

Re: Make Unique Alphanumeric value

Bmohammad — Wed, 14 Oct 2020 10:21:51 GMT

Dear Joshua and Bing,

Thanks for your kind help

I attach one picture which make you easy to understand.

In this picture fIeld _1 have value which have duplicate and I want to make unique code e.g AAC-4091

Re: Make Unique Alphanumeric value

Bmohammad — Wed, 14 Oct 2020 11:14:29 GMT

Dear Joshua and Bing,

Thanks for your kind help

I attach one picture which make you easy to understand.

In this picture fIeld _1 have value which have duplicate and I want to make unique code e.g AAC-4091

Re: Make Unique Alphanumeric value

JoshuaBixby — Sat, 11 Dec 2021 08:08:14 GMT

Try this in interactive Python Window, just update the value for lyr.

import arcpy
from itertools import product
from string import ascii_uppercase

lyr = # layer name or path to feature class
flds = ["Field_1", "Unique"]

incr = ("".join(i) for i in product(ascii_uppercase, ascii_uppercase))

with arcpy.da.UpdateCursor(lyr, flds) as cur:
    for fld1, uniq in cur:
        cur.updateRow([fld1, "A{}-{}".format(next(incr), fld1)])

‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Make Unique Alphanumeric value

Bmohammad — Thu, 22 Oct 2020 07:33:08 GMT

Thanks Joshua it works thanks for your kind help

It stops when it works up to AZZ-222 if we need more then we have to change

 cur.updateRow([fld1, "B{}-{}".format(next(incr), fld1)])

first letter to B

Is there any method that when A finished it automatically change A to B and so on

Thanks Joshua

Re: Make Unique Alphanumeric value

JoshuaBixby — Sat, 11 Dec 2021 08:08:18 GMT

The following code increments the first letter as well:

import arcpy
from itertools import product
from string import ascii_uppercase

lyr = # layer name or path to feature class
flds = ["Field_1", "Unique"]

incr = ("".join(i) for i in product(ascii_uppercase, ascii_uppercase, ascii_uppercase))

with arcpy.da.UpdateCursor(lyr, flds) as cur:
    for fld1, uniq in cur:
        cur.updateRow([fld1, "{}-{}".format(next(incr), fld1)])‍‍‍‍‍‍‍‍‍‍‍‍

Re: Make Unique Alphanumeric value

Bmohammad — Mon, 26 Oct 2020 05:40:13 GMT

Thanks Brother it works. I sincerely appreciate your help