Using ArcGis 10.2

I have a script converting the nodes of a net into polygons. The polygons should be either triangles or rectangles but the script doesn't build polygon as rectangle, skipping the fourth vertice. Being not fluent in python, I can't spot the mistake: it looks like the Array stores or restitute only 3 values instead of 4. Could you please help me to fix this?

enter image description here

Here the code:

import sys
import arcpy
import os
outfileGDB =arcpy.env.workspace= arcpy.GetParameterAsText (0)
arcpy.env.overwriteOutput = True
polygonsFile = arcpy.GetParameterAsText (1)
verticesFile = arcpy.GetParameterAsText (2)
srtxt = arcpy.GetParameterAsText(3)
sr = arcpy.SpatialReference()
Output = arcpy.GetParameterAsText(4)
polygontable = arcpy.TableToTable_conversion(in_rows=polygonsFile,
                                  out_path= outfileGDB,
vertextable = arcpy.TableToTable_conversion(in_rows=verticesFile,
                                  out_path= outfileGDB,
outfc =arcpy.CreateFeatureclass_management (outfileGDB,Output,"POLYGON","#","DISABLED","ENABLED",sr)
arcpy.AddField_management (outfc,"ID_el", "LONG", "", "", "", "", "NULLABLE")
with arcpy.da.SearchCursor(polygontable,["OID@","Eltyp","ID_el","IDpt1","IDpt2","IDpt3","IDpt4"]) as poly_cur:
    print "polygons"
    if "ELtyp"== "E3T":    
        poly_dict = {x[2]: x[3:5] for x in poly_cur}
        poly_dict = {x[2]: x[3:6] for x in poly_cur}
with arcpy.da.SearchCursor(vertextable,"*") as vertex_cur:
    print "vertices"
    vertex_dict = {x[1]: x[2:] for x in vertex_cur}
polyArray = {}
for polykey in poly_dict:
    polynodes = poly_dict[polykey]
    coordsList = []
    for polynode in polynodes:
        coords = (v for k,v in vertex_dict.iteritems() if k == polynode)
        for coord in coords:
    polyArray[polykey] = coordsList
features = []
for key,values in polyArray.iteritems():
    features.append((key,arcpy.Polygon(arcpy.Array([arcpy.Point(*value) for value in values]), sr,
                                      True))) #True - for has_z parameter
for feature in features:
    with arcpy.da.InsertCursor(outfc,["ID_el","SHAPE@"]) as cur:
arcpy.JoinField_management(outfc,"ID_el",polygontable,"ID_el",["IDpt1", "IDpt2", "IDpt3", "IDpt4", "Mat"])      
  • To close your polygons with four vertices there should be five coordinates i.e. the fifth one should be the same as the first. – PolyGeo Oct 21 '15 at 6:54
  • @PolyGeo: it Looks like the mistake was not in this script but in the one used to produce the "polygonsFile" , which I modified to implement the last Point. Your comment put me on the right path. Problem fixed, thanks! – PMessager Oct 21 '15 at 8:39

Without delving into your code whenever I see triangles instead of the expected rectangles my suspicion is that only four instead of five coordinates are being used to form them.

For a rectangle you would expect to see five coordinates with the first and last (fifth) being the same, in order to close the polygon.

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