topic Create a line with attributes based on origin and destination points with Python in Python Questions

Create a line with attributes based on origin and destination points with Python

RenatoSilveira_Borges — Mon, 26 Sep 2011 19:15:25 GMT

I need to create a line with attributes based on origin and destination points with Python.

The source table is like a:

ORIGIN_X, ORIGIN_Y, DEST_X, DEST_Y, ATTRIBUTE_1, ATTRIBUTE_2, ATTRIBUTE_3

I have used the code in this article [http://support.esri.com/en/knowledgebase/techarticles/detail/31879] to create the lines, but i can't put the attributes in the shapefile.

import sys, string, os, arcgisscripting

gp = arcgisscripting.create()

gp.Overwriteoutput = 1

#Specify the location for the new shapefile.

gp.CreateFeatureclass("C:/temp/", "test_line.shp", "POLYLINE")

#Define Coordinate System

gp.workspace = "C:/temp/"

gp.toolbox = "management"

coordsys = "Coordinate Systems/Geographic Coordinate Systems/North America/North American Datum 1983.prj"

gp.defineprojection("test_line.shp", coordsys)

#Open a cursor to insert rows into the shapefile.

cur = gp.InsertCursor("C:/temp/test_line.shp")

#Create an Array and Point object.

lineArray = gp.CreateObject("Array")

pnt = gp.CreateObject("Point")

#Open a cursor on the table of XY coordinates to read from.

rows = gp.SearchCursor("c:/pythonTest.dbf")

#Reset the cursor to the top.

row = rows.Next()

#Loop through each record in the XY table..

while row:

    #Set the X and Y coordinates for origin vertex.

    pnt.x = row.GetValue("Origin_x")

    pnt.y = row.GetValue("Origin_y")



    #Insert it into the line array

    lineArray.add(pnt)



    #Set the X and Y coordinates for destination vertex

    pnt.x = row.GetValue("dest_x")

    pnt.y = row.GetValue("dest_y")

    #Insert it into the line array

    lineArray.add(pnt)



    #Go to next row in table.

    row = rows.Next()

    #Insert the new poly into the feature class.

    feat = cur.NewRow()

    feat.shape = lineArray

    cur.InsertRow(feat)

    lineArray.RemoveAll()



del cur, row, rows

Re: Create a line with attributes based on origin and destination points with Python

RenatoSilveira_Borges — Fri, 30 Sep 2011 17:13:12 GMT

No one? Help, please!!

Re: Create a line with attributes based on origin and destination points with Python

DuncanHornby — Mon, 10 Oct 2011 14:31:58 GMT

It looks like you are almost there. All you need to do is create the attribute fields you wish to populate in your output dataset. You do this by using the AddField tool and do that after you have called the createfeatureclass tool. You already have the code to extract data from your input file so you simply extract your attributes and write these to your new output row which you are calling feat.

If you can't work out how to do that then upload a sample of your input file so people can see what fields you are wanting to pass to your output dataset.

Duncan

Re: Create a line with attributes based on origin and destination points with Python

KimOllivier — Tue, 11 Oct 2011 03:37:47 GMT

At 10.0 there is a tool to turn a table into points and another to turn points into lines.
To save some coding.

Re: Create a line with attributes based on origin and destination points with Python

OlivierOlivier — Tue, 25 Oct 2011 16:13:20 GMT

I have a script that works using

row.SetValue("y",pnt.y)
rows.UpdateRow(row)

y field must exists before like Hornbydd said

Olivier