[OSGeo-Discuss] methods for programatically adding fields to shapefiles

[Tyler Erickson]

Thanks for all the suggestions.  Although it is still a work in progress,
it's looking like the ogr library approach suggested by David will work out
for me...

- Tyler


def create_formatted_shapefile_using_ogr(infile, outfile):
        
    # setup a spatial reference
    srs_out = osr.SpatialReference()
    srs_out.SetFromUserInput('WGS84')

    ogrdriver = ogr.GetDriverByName('ESRI Shapefile')

    dsInput = ogrdriver.Open(infile)
    mLayer = dsInput.GetLayer()
    featureCount = mLayer.GetFeatureCount()
        
    # create the output shapefile
    if os.path.exists(outfile):
        ogrdriver.DeleteDataSource(outfile)
    dsOutput = ogrdriver.CreateDataSource(outfile)
    outLayer = dsOutput.CreateLayer(dsOutput.GetName(), \
                                geom_type = ogr.wkbPolygon, \
                                srs = srs_out)
    outLayer.CreateField(ogr.FieldDefn('start_date', ogr.OFTDate))
    outLayer.CreateField(ogr.FieldDefn('fire_code', ogr.OFTString))
    outLayer.CreateField(ogr.FieldDefn('fire_name', ogr.OFTString))
    outLayer.CreateField(ogr.FieldDefn('source', ogr.OFTString))
    
    print 'FeatureCount = ' + str(featureCount)
    
    for iFeature in range(0,mLayer.GetFeatureCount()):
        inFeature = mLayer.GetFeature(iFeature)
        
        geom = inFeature.GetGeometryRef()
        start_date = inFeature.GetFieldAsString('year') + "-" + \
                    inFeature.GetFieldAsString('startmonth') + "-" + \
                    inFeature.GetFieldAsString('startday')
        
        # reproject to WGS84
        geom.TransformTo(srs_out)
        
        # write the attributes to the output file
        outFeature = ogr.Feature(feature_def=outLayer.GetLayerDefn())
        outFeature.SetGeometry(geom)
        outFeature.SetFID(1)
        outFeature.SetField('fire_code', inFeature.GetField('fire_id'))
        outFeature.SetField('fire_name', inFeature.GetField('fire_name'))
        outFeature.SetField('source', infile)
        outLayer.CreateFeature(outFeature)
        
        outFeature.Destroy()
        inFeature.Destroy()
    
    dsInput.Destroy()
    dsOutput.Destroy()
 

-- 
View this message in context: http://n2.nabble.com/methods-for-programatically-adding-fields-to-shapefiles-tp1395535p1437802.html
Sent from the OSGeo Discuss mailing list archive at Nabble.com.