topic Re: New to Python in Web AppBuilder Custom Widgets Questions

New to Python

ChrisKendrick — Wed, 06 Feb 2019 17:00:46 GMT

I am new to Python and I am trying to write a code in Field calculator to update a field using another field in attribute table.

Could someone please help me with this?

Thanks,

Chris

Re: New to Python

DanPatterson_Retired — Thu, 07 Feb 2019 02:36:45 GMT

well you might want the Python‌ space, so I would move this question if I could, but a Share might do

Re: New to Python

JoshuaBixby — Thu, 07 Feb 2019 16:47:44 GMT

Assuming you read Calculate Field—Data Management toolbox | ArcGIS Desktop , what part of the syntax are you having difficulties with specifically?

Re: New to Python

BenBond — Fri, 15 Feb 2019 15:56:31 GMT

You will need to write a function to do what you want and then call that function from the field calculator.

Arcmap: click the show codeblock check box and paste your function in the Pre-Logic Script code box.

Pro: paste your function in the code block.

Make sure the expression type is set to python.

Then pace the field you want to call in the expression.

So for example this is a simple script that will run a regular expression on the specified field and return any number at the beginning of the field. For me I use it to collect house numbers at the front of an address.

So as you can see this will calculate for the field HOUSENUM. I pass the field LSN to the regex function that I defined in the code block. It runs some regular expression stuff and returns the text variable which is stored in the field HOUSENUM.