计算几何面积

 from osgeo import ogr

wkt = "POLYGON ((1162440.5712740074 672081.4332727483, 1162440.5712740074 647105.5431482664, 1195279.2416228633 647105.5431482664, 1195279.2416228633 672081.4332727483, 1162440.5712740074 672081.4332727483))"
poly = ogr.CreateGeometryFromWkt(wkt)
print "Area = %d" % poly.GetArea()