python GDAL 读写shp文件

gdal包用于处理栅格数据，ogr用于处理矢量数据。

 1 #!C:\Program Files\pythonxy\python\python.exe
 2 #-*- coding:gb2312 -*-
 3
 4 from osgeo import ogr,osr,gdal
 5 import os
 6
 7 """
 8 Understanding OGR Data Type:
 9 Geometry  - wkbPoint,wkbLineString,wkbPolygon,wkbMultiPoint,wkbMultiLineString,wkbMultiPolygon
10 Attribute - OFTInteger,OFTReal,OFTString,OFTDateTime
11 """
12
13 class ARCVIEW_SHAPE:
14     #------------------------------
15     #read shape file
16     #------------------------------
17     def read_shp(self,file):
18         #open
19         ds = ogr.Open(file,False) #False - read only, True - read/write
20         layer = ds.GetLayer(0)
21         #layer = ds.GetLayerByName(file[:-4])
22         #fields
23         lydefn = layer.GetLayerDefn()
24         spatialref = layer.GetSpatialRef()
25         #spatialref.ExportToProj4()
26         #spatialref.ExportToWkt()
27         geomtype = lydefn.GetGeomType()
28         fieldlist = []
29         for i in range(lydefn.GetFieldCount()):
30             fddefn = lydefn.GetFieldDefn(i)
31             fddict = {'name':fddefn.GetName(),'type':fddefn.GetType(),
32                       'width':fddefn.GetWidth(),'decimal':fddefn.GetPrecision()}
33             fieldlist += [fddict]
34         #records
35         geomlist = []
36         reclist = []
37         feature = layer.GetNextFeature()
38         while feature is not None:
39             geom = feature.GetGeometryRef()
40             geomlist += [geom.ExportToWkt()]
41             rec = {}
42             for fd in fieldlist:
43                 rec[fd['name']] = feature.GetField(fd['name'])
44             reclist += [rec]
45             feature = layer.GetNextFeature()
46         #close
47         ds.Destroy()
48         return (spatialref,geomtype,geomlist,fieldlist,reclist)
49
50     #------------------------------
51     #write shape file
52     #------------------------------
53     def write_shp(self,file,data):
54         gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8","YES");
55         gdal.SetConfigOption("SHAPE_ENCODING","UTF-8");
56         spatialref,geomtype,geomlist,fieldlist,reclist = data
57         #create
58         driver = ogr.GetDriverByName("ESRI Shapefile")
59         if os.access(file, os.F_OK ):
60             driver.DeleteDataSource(file)
61         ds = driver.CreateDataSource(file)
62         #spatialref = osr.SpatialReference( 'LOCAL_CS["arbitrary"]' )
63         #spatialref = osr.SpatialReference().ImportFromProj4('+proj=tmerc ...')
64         layer = ds.CreateLayer(file[:-4],srs=spatialref,geom_type=geomtype)
65         # print type(layer)
66         #fields
67         for fd in fieldlist:
68             field = ogr.FieldDefn(fd['name'],fd['type'])
69             if fd.has_key('width'):
70                 field.SetWidth(fd['width'])
71             if fd.has_key('decimal'):
72                 field.SetPrecision(fd['decimal'])
73             layer.CreateField(field)
74         #records
75         for i in range(len(reclist)):
76             geom = ogr.CreateGeometryFromWkt(geomlist[i])
77             feat = ogr.Feature(layer.GetLayerDefn())
78             feat.SetGeometry(geom)
79             for fd in fieldlist:
80                 # print(fd['name'],reclist[i][fd['name']])
81                 feat.SetField(fd['name'],reclist[i][fd['name']])
82             layer.CreateFeature(feat)
83         #close
84         ds.Destroy()
85
86 #--------------------------------------
87 #main function
88 #--------------------------------------
89 if __name__ == "__main__":
90     test = ARCVIEW_SHAPE()
91     data = test.read_shp(r'../data/chn_adm2.shp')
92     spatialref,geomtype,geomlist,fieldlist,reclist = data
93     test.write_shp(r'../data/chn_adm2_bak.shp',[spatialref,geomtype,geomlist,fieldlist,reclist])