Creating a new feature class with python and then adding attibutes

Question

I am having trouble adding rows to a shapefile after it has been created. I'm not sure if I need to create the shapefile in memory and add the data or creating then re-open the file. While I've attempted to re-open the file, it will exit code 1 that file doesn't yet exist. Any and all suggestion would be useful. (except setting it on fire). I'm getting a "AttributeError: Row: Error in parsing arguments for SetValue" .... Please help.

for row in arcpy.da.SearchCursor(featureClass, ['FID','SHAPE@JSON','STREAM_ID','REACH_ID','SR_ID','STATION','INTERP','XS_ID','WSP001','WSP002','WSP003','WSP004','WSP005','WSP006','WSP007']):
featureClassData.append([row[0],row[1],row[2],row[3],row[4],row[5],row[6],row[7],row[8],row[9],row[10],row[11],row[12],row[13],row[14]])
outPutPath = "C:\\projectTemp\\FloodAnalysis\\output"
for i in range(0, len(featureClassData) -1):
FirstRowData = featureClassData[i]
SecondRowData = featureClassData[i+1]
FirstRowData[1] = eval(FirstRowData[1])
for cord in FirstRowData[1]['paths']:
 for c in cord:
 point = arcpy.Point(c[0],c[1])
 dataSetCreate = arcpy.CreateFeatureclass_management(outPutPath, 'test_section_' + `i` ,"", featureClass)
 dataSet = arcpy.InsertCursor(dataSetCreate)
 row1 = dataSet.newRow()
 row1.Shape = arcpy.geometries.Polyline(array1,spatialRef)
 row1.setValue(FirstRowData[2], FirstRowData[3], FirstRowData[4],
 FirstRowData[5], FirstRowData[6], FirstRowData[7],
 float(FirstRowData[8]), float(FirstRowData[9]), float(FirstRowData[10]),
 float(FirstRowData[11]), float(FirstRowData[12]),
 float(FirstRowData[13]), float(FirstRowData[14]))
 dataSet.insertRow(row1)

Answer 1

The dataSetCreate variable is a Result object, not a feature class. You need to pass the path to the feature class to the insert cursor which you can get from the Result object using the getOutput method. Try:

dataSetCreate = arcpy.CreateFeatureclass_management(outPutPath, 'test_section_' + `i` ,"", featureClass)
dataSet = arcpy.InsertCursor(dataSetCreate.getOutput(0))

The second issue I can see is that you're using an arcpy.InsertCursor but trying to use arcpy.da.InsertCursor style syntax. They have quite different syntax for inserting rows.

This is what you're currently doing which will result in the AttributeError: Row: Error in parsing arguments for SetValue exception:

dataSet = arcpy.InsertCursor(dataSetCreate)
...
row1.setValue([list, of, field, values]) <--- this is the problem
dataSet.insertRow(row1)

Either use:

dataSet = arcpy.InsertCursor(dataSetCreate.getOutput(0))
...
row1.setValue(column_name, column_value)
row1.setValue(another_column_name, another_column_value)
etc...
dataSet.insertRow(row1)

Or:

dataSet = arcpy.da.InsertCursor(dataSetCreate.getOutput(0), [list, of, field, names])
...
dataSet.insertRow ([list, of, field, values])

Answer 2

If I understand correctly, I think the problem is here:

dataSetCreate = arcpy.CreateFeatureclass_management(outPutPath, 'test_section_' + `i` ,"", featureClass)
dataSet = arcpy.InsertCursor(dataSetCreate)

I believe when you assign arcpy.CreateFeatureclass_management to a variable, it will not be 'run' until it is called upon in the next line, at which point the Insert Cursor will be run first and will call a FC that doesn't exist yet as the create method has not been run.

Additionally I am pretty sure that the create FC method does not return a string of the output path to the created FC. Not sure on that, just know that I have never done it that way. I will check that out in the docs though.

Maybe try something like this:

arcpy.CreateFeatureclass_management(outPutPath, 'test_section_' + str(i) + '.shp' ,"", featureClass)
dataSet = arcpy.InsertCursor(outPutPath + '\\test_section_' + str(i) + '.shp')

This way you run the create FC method first and then just use the path to the output FC as an arg in the InsertCursor creation.

• Ryan Bertram: I think you're right, so the question is how to I get the fc created before it goes the cursor attempts to add rows of data?
• nmpeterson: You'll need to use outPutPath + '\\test_section_{0}'.format(i) to reference the actual feature class. Also, I'd use 'test_section_{0}'.format(i) instead of 'test_section_' + `i`
• nmpeterson: From that error, it looks like you omitted the first underscore in 'test_section_'
• Chaz: Are you working with shapefiles? If so you will also need to append '.shp' as such: outPutPath, 'test_section_' + str(i) + '.shp'
• user2856: @Chaz This is partly correct in that you need to use the path to the feature class when creating the insert cursor, but your reasoning is wrong. The feature class is created as soon the the CreateFeatureclass tool is run.The variable dataSetCreate is an arcpy Result object. You can get the feature class path using the Result object getOutput method - dataSetCreate.getOutput(0)