import os
import sys

os.chdir('Y:/data/sw_pacific/tonga/anuga/topographies')

polyline_file=open('topography_tongatapu.txt','r')
lines=polyline_file.readlines()
polyline_file.close()

filetoedit= open('topography_tongatapu1.txt','w')
q= 'easting,northing,elevation\n'
filetoedit.write(q)
for line in lines [0:]:
    field = line.split('\t')
    x= float(field[0])
    y=float(field[1])
    z=float(field[2])
    s= '%f,%f,%f\n' %(x,y,z)
    filetoedit.write(s)
    
filetoedit.close()