将功能附加到现有shapefile

时间:2018-04-12 08:53:45

标签: python shapefile gdal ogr

使用python我尝试打开shapefile,添加一个功能并保存。我认为在图层中创建一个特征会导致该函数返回6(而0表示我认为没有错误)。我的代码:

# -*- coding: utf-8 -*-
from osgeo import ogr
import os

''' Add feature '''
driver = ogr.GetDriverByName('ESRI Shapefile')
data_source = driver.Open(src, 0)
in_layer = data_source.GetLayer()

# create the feature
feature = ogr.Feature(in_layer.GetLayerDefn())
feature_properties = {'INDEX_NO': 39470.0,
                  'REGION_NO': 39330.0,
                  'NAME': 'VOLTRI',
                  'COUNTRY': 'IT',
                  'LATITUDE': 44.421,
                  'LONGITUDE': 8.784,
                  etc.}

for k, v in feature_properties.items():
    # Set the attributes using the values from the dictionary
    feature.SetField(k, v)

# create the WKT for the feature using Python string formatting
wkt = "POINT(%f %f)" %  (float(feature_properties['LONGITUDE']) , float(feature_properties['LATITUDE']))

# Create the point from the Well Known Txt
point = ogr.CreateGeometryFromWkt(wkt)

# Set the feature geometry using the point
feature.SetGeometry(point)
feature.SetFID(in_layer.GetFeatureCount())

# Create the feature in the layer (shapefile)
print(in_layer.CreateFeature(feature)) # prints 6, I would expect 0

# Dereference the feature
feature.Destroy()

# Save and close the data source
data_source = None

我已经从图层中的其他要素复制了属性,只更改了坐标和名称。

帮助将非常感激,因为我很难找到GDAL / OGR for python的好文档。

1 个答案:

答案 0 :(得分:0)

找到答案,打开文件进行阅读是个问题。 从这个资源我发现0代表阅读,1代表写作:https://pcjericks.github.io/py-gdalogr-cookbook/vector_layers.html

data_source = driver.Open(src, 0) # for reading
data_source = driver.Open(src, 1) # for writing