Question

在ogr2ogr中使用Python，我正在尝试将CSV转换为shapefile。 CSV中的一列名为“Polygon”，其中包含WKT，如下所示：POLYGON((long lat, long lat, long lat, etc.))目前，我可以使用正确的投影制作多边形shapefile，但几何图形为空。

如何修改ogr2ogr参数以使用每行WKT正确创建几何图形？目前我有这样的事情：

ogr2ogr.main(["", "-a_srs", "EPSG:4326", "-f", "ESRI Shapefile", "output.shp", "input.csv", "-nlt", "POLYGON"])

Answer 1

我并不习惯ogr2ogr.py，但如果你知道一些基本的python绑定ogr，它可以很容易地完成。这是一个简单的例子，可以做你想做的事情：

import ogr, osr, csv

spatialref = osr.SpatialReference()  # Set the spatial ref.
spatialref.SetWellKnownGeogCS('WGS84')  # WGS84 aka ESPG:4326

driver = ogr.GetDriverByName("ESRI Shapefile")
dstfile = driver.CreateDataSource('output.shp') # Your output file

# Please note that it will fail if a file with the same name already exists
dstlayer = dstfile.CreateLayer("layer", spatialref, geom_type=ogr.wkbPolygon) 

# Add the other attribute fields needed with the following schema :
fielddef = ogr.FieldDefn("ID", ogr.OFTInteger)
fielddef.SetWidth(10)
dstlayer.CreateField(fielddef)

fielddef = ogr.FieldDefn("Name", ogr.OFTString)
fielddef.SetWidth(80)
dstlayer.CreateField(fielddef)

# Read the feature in your csv file:
with open('input.shp') as file_input:
    reader = csv.reader(file_input)  # Can be more intuitive with a DictReader (adapt to your needs)
    next(reader) # Skip the header
    for nb, row in enumerate(reader): 
        # WKT is in the second field in my test file :
        poly = ogr.CreateGeometryFromWkt(row[1])
        feature = ogr.Feature(dstlayer.GetLayerDefn())
        feature.SetGeometry(poly)
        feature.SetField("ID", nb) # A field with an unique id.
        feature.SetField("Name", row[0]) # And a name (which is in the first field of my test file)
        dstlayer.CreateFeature(feature)
    feature.Destroy()
    dstfile.Destroy()

当然需要根据您的具体情况进行调整，但这段代码可以是第一次启动并完成工作。
（如果你想在GDAL / ogr python绑定上有其他一些例子，你可以查看these recipes）

将带有WKT列的CSV转换为Shapefile

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