[GIS] Programmable buffers using GDAL and python

gdalpythonvector

Is there a way to programmatically generate buffer layers for vector layers using GDAL and python?

Best Answer

ogr has a buffer method. I am sitting behind a serious firewall, so I can't really dig around the internet too much, but here is a little snippet I found that should do the trick. I didn't test this, and will need some modification (i.e. set your driver type)- but it should get you going in the right direction. 

#buffer.py
import sys,os
from osgeo import ogr

def buffer(infile,outfile,buffdist):
    try:
        ds=ogr.Open(infile)
        drv=ds.GetDriver()
        if os.path.exists(outfile):
            drv.DeleteDataSource(outfile)
        drv.CopyDataSource(ds,outfile)
        ds.Destroy()

        ds=ogr.Open(outfile,1)
        lyr=ds.GetLayer(0)
        for i in range(0,lyr.GetFeatureCount()):
            feat=lyr.GetFeature(i)
            lyr.DeleteFeature(i)
            geom=feat.GetGeometryRef()
            feat.SetGeometry(geom.Buffer(float(buffdist)))
            lyr.CreateFeature(feat)
        ds.Destroy()
    except:return False
    return True

if __name__=='__main__':
    usage='usage: buffer <infile> <outfile> <distance>'
    if len(sys.argv) == 4:
        if buffer(sys.argv[1],sys.argv[2],sys.argv[3]):
            print 'Buffer succeeded!'
            sys.exit(0)
        else:
            print 'Buffer failed!'
            sys.exit(1)
    else:
        print usage
        sys.exit(1)
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