Python script help for row.SetValue() function

[deleted-user-rQoEFM5qzbHE]

I am creating a python script and have a question about the row.SetValue() function. I have read in a table and a feature class along with a string value that represents one of the fields in the feature class. I join the table to the feature class and perform some calculations. Based on the result from those calculations, I then need to set the value of the of the field denoted by the string value. I am not sure what the proper code (if this is even possible) to do this. Here is what I have tried.

First, I tried to set the 'SchoolLevel' field to a value:
[INDENT]row.SetValue(SchoolLevel, M[0][1])[/INDENT]
I am pretty sure that this doesn't work because there is a join.

So, then I tried to add in the name of the feature class to the code as such:
[INDENT]row.SetValue(Scenario_Template_1011.SchoolLevel, M[0][1])[/INDENT]

This didn't work, so then I tried to put the feature class name in quotes:
[INDENT]row.SetValue("Scenario_Template_1011."SchoolLevel, M[0][1][/INDENT]
This throws me an invalid syntax error before I can even run the script. This makes sens, but I am not sure how to correctly code this up.

Basically, Scenario_Template_1011 is the name of the feature class that is joined by another table and SchoolLevel is a variable representing a field in Scenario_Template_1011. I am trying to set the value of that field using a cell in a matrix that I created.

Thanks in advance for any help!

[RussellKallstrom]

Don't know much about Python or how joins work, but can you adjust the UpdateCursor to include fewer fields (4th item in argument)?

Otherwise, next thing I would try would be a combination of the SearchCursor and UpdateCursor, though I don't know how these run concurrently.

[JeffLee]

What are M[0][1]?  are these values from a python list? if so try,


row.SetValue(SchoolLevel, M[0] + M[1])

[deleted-user-rQoEFM5qzbHE]

Thanks for the responses. I think I know what my issue is but I have run into other problems and have to fix those before I know for sure. Ah, the joys of coding :).

Snoop, M is an nxm matrix. In the example I am accessing the value of the cell in the first column, second row.

[deleted-user-rQoEFM5qzbHE]

I have been unable to figure out why this is not working. Here is the code in the hopes that someone will be able to see where I am going wrong.

rows = gp.UpdateCursor(inTable)
row = rows.next()

try:
    while row:
        for i in range(0,numSchools):
            school = row.GetValue(Elem)
            M[1] = school

        M.sort(lambda x, y: cmp(x[1], y[1]))
        M.reverse()

        if M[0][1] > 0:
            school = M[0][0]
            row.SetValue("[ScenarioTemplate_1011." + String + "]", school)

        gp.AddMessage("You made it through the if statement")
        rows.UpdateRow(row)
        row = rows.next()

except:
    gp.AddError("Failed to set the value of new scenario field to new school assignment")

Thanks.

[BiniamTes]

hello there ,
i guess i have similar problem would appreciate if you have any idea. i want to copy the records of a single row and dublicate it in the same attribute table uisng python script that is first getvalue and then setvalue. i tired first to insert a new row then , put the value of the row to be copied in a list[] and then try to set the values of the new row from the list , but it did not work. any idea ...
...............................................
rows = gp.UpdateCursor(fc)
cur = gp.searchcursor(fc)
row = cur.next()
i = 0
while row:
    if row.Urban ==22:   # this is just to check if it is the right row
        fields = gp.Listfields(fc)
        field = fields.next()
        i = i
        while field:
            value = Store                          # store is the collection of records from the row to be copied
            row.setvalue("(field.name)", value)
            #rows.UpdateRow(row)
            i+=1
            field = fields.next()
        del field
    rows.UpdateRow(row)
    row = cur.next()
del row
del rows 
....................................................
thanx

[markdenil]

to biniamts;
You cannot add a row with an Update Cursor. Only InsertCursor has a new row method.
try running your search cursor first, and building either a nested list (if the existing records are in the order you would like to write them) OR building a dictionary (if you want to reference the records by a unique key value). Run an InsertCursor from whichever you built to add the new duplicated records.

[GeorgeNewbury]

Also be sure to check your casing:

the methods for Getting and Setting Values are:

getValue(field_name)
setValue(field_name, object)

--Took this straight for ArcGIS help

Some of the posts in this thread had the wrong casing (e.g. 'SetValue')

-George

[AndresCastillo]

Thanks for that, I was looking where I could find docs for those methods.

They are methods of the row object:

Row—ArcGIS Pro | Documentation 

[markdenil]

Yes, that is a real concern with Arc10. Arc9 was indifferent to capitalization on geoprocessor comands, but Arcpy is a stickler.