Question

我已经下载了一个openstreetmap shapefile并希望提取某些功能（使文件不那么重，只有我感兴趣的那些，例如来自道路的自行车道）。我该怎么做，我现在可以打开文件并使用以下代码查看功能：

from osgeo import ogr

file = ogr.Open('gis.osm_roads_free_1.shp')
shape = file.GetLayer(0)

# here I want to filter on an "fclass" value

有关如何执行此操作的任何建议吗？

Answer 1

试试这个。

from osgeo import ogr

def create_filtered_shapefile(value, filter_field, in_shapefile, out_shapefile):
    input_layer = ogr.Open(in_shapefile).GetLayer()

    # Filter by our query
    query_str = '"{}" = "{}"'.format(filter_field, value)
    input_layer.SetAttributeFilter(query_str)

    # Copy Filtered Layer and Output File
    driver = ogr.GetDriverByName('ESRI Shapefile')
    out_ds = driver.CreateDataSource(out_shapefile)
    out_layer = out_ds.CopyLayer(input_layer, str(value))
    del input_layer, out_layer, out_ds
    return out_shapefile

# for example
create_filtered_shapefile('highways', 'fclass', 'gis.osm_roads_free_1.shp')

python OGR Shapefile导出功能

1 个答案: