topic Re: Extract field values and use as parameter in Python Questions

Extract field values and use as parameter

KyleGallagher — Thu, 19 May 2011 21:02:33 GMT

I'm using v10 and am I am wanting to extract a field value from a shapefile and use that value as a new parameter in my Python script. However, there doesn't seem to be an easy way to do this. There is a ModelBuilder Only tool named Get Field Value, but it can't be used in Python. You can throw the tool into ModelBuilder, export it to a Python script, and try and use the code, but the following line of code did not work as there was an error opening the toolbox:

arcpy.ImportToolbox("Model Functions")

I'm basically converting my shapefile to a table view, trying to run Get Field Value, and using that value as a parameter. Any suggestions are greatly appreciated!!

Thanks,
KG

Re: Extract field values and use as parameter

ChrisBoyce — Fri, 20 May 2011 01:50:57 GMT

I just did something similar but used a search cursor. I iterated through every row of a single field, then used that to build a definition query with the layer object. Sounds like a cursor might work for you...

Chris.

Re: Extract field values and use as parameter

KyleGallagher — Fri, 20 May 2011 02:58:46 GMT

I just did something similar but used a search cursor. I iterated through every row of a single field, then used that to build a definition query with the layer object. Sounds like a cursor might work for you...

Chris.

Could you supply the search cursor code that worked for you? I've seen it Arc 9 but I know it's a little different now with arcpy in Arc 10.

Thanks!

Re: Extract field values and use as parameter

TerrySilveus — Sat, 11 Dec 2021 23:23:57 GMT

Here is some cursor code and a way to get the value of a field

        rows = arcpy.SearchCursor(pathAndNameOfShapefile)
        for row in rows:
            valueOfField = row.getValue(fieldName) 
            #do something here with value

        del rows #delete cursor object variable
        del row #delete row object variable

NOTE: pathAndNameOfShapefile and fieldName are set up as string variables if you use the actual path and name put quotes around it - the same goes for field name

You should also check out UpdateCursor and InsertCursor http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//002z0000001q000000.htm
Specifying a query to get a specific set of rows http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Specifying_a_query_in_Python/002z0000001r000000/
Row methods http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//000v000000nv000000.htm