Using shapely package for Python how to export the resulting shapely objects such as buffer to a DXF file?
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4 Answers
BTW, if you appreciate Shapely, you may also appreciate Fiona. The Fiona example in https://gist.github.com/1886782 could be adapted to convert a shapefile to DXF.
with fiona.collection("file.shp", "r") as source:
with fiona.collection(
"file.dxf",
"w",
driver="DXF",
schema=source.schema,
) as sink:
# Do whatever you like to records
results = some_function(source)
sink.writerecords(results)
It coughs up a lot of warnings about mismatch between GIS simple feature and DXF data models but does write a file of entities.
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1Thanks for introducing
Fionaand also thanks for your interesting packageShapely. You are surely doing good job. Commented Feb 23, 2012 at 17:43 -
@sgillies That's awesome. If you need any further contributors please give me a shout! Also, any plans for GDAL? Commented Feb 23, 2012 at 22:34
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BTW is there any pre-compiled for windows (Python 2.72) release of
Fiona? Commented Feb 24, 2012 at 2:39 -
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Shapely doesn't directly support exporting to DXF - it supports export to Well Known Text (WKT), Well Known Binary (WKB), Numpy arrays and GeoJSON objects (interoperation from the Shapely manual). As such you need a package that can transform from one of these formats to DXF.
I'd suggest OGR as the way to go for my money. The easiest method would be to simply export your shapely geometries to a GeoJSON file through Python using shapely.geometry.mapping(obj), e.g.
from shapely.geometry import mapping
import json
open("buffer.geojson", "wb").write(json.dumps(mapping(buffer_obj)))
Then simply use the ogr2ogr utility to transform the GeoJSON to a DXF file, e.g.
ogr2ogr -f DXF buffer.dxf buffer.geojson
Then, if you're keen you can look up the GDAL/OGR Python bindings and do it within a single script. Hope this helps!
answered Feb 23, 2012 at 12:29
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Thanks a lot. You gave many ideas which are very useful. I would like to try OGR through Python. This a good answer. Commented Feb 23, 2012 at 13:37
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1As explained in gis.stackexchange.com/a/7744/390 there's a mismatch between the GeoJSON and DXF formats. Looks like you'll want to have a DXF template into which to stuff your lines.– sgilliesCommented Feb 23, 2012 at 15:50
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1Just to mention in execution of the provided code an error come up: "write requires string/buffer". So I changed it as:
write(str(mapping(buffer_obj)))and it is OK now. I use Python 2.72 BTW. Commented Feb 23, 2012 at 17:14 -
and I also had to replace
()with[]in the produced GeoJSON file to bypass another error caused usingogr2ogr.exe. Those may be changes in software or I'm missing something obvious! Anyway, with these two tricks it produced a DXF file successfully. Commented Feb 23, 2012 at 17:33 -
However
DXFfile may have some issues since I could not open it by different software such as LibreCAD, SketchUp etc. Commented Feb 23, 2012 at 17:59
You can do that using Geopandas and Fiona Libraries Here is the code to read a file using Geopandas and export it as a DXF File.
import geopandas as gpd
from geopandas import GeoDataFrame
import fiona
#Read file using geopandas
x = gpd.read_file(filename with path)
#Save as DXF
x.geometry.to_file(output file name, driver="DXF")
Also, check the answer in the below link. https://gis.stackexchange.com/a/377412/160313
Nowadays new ways came along, thanks to the __geo_interface__ interface standard and the ezdxf library.
A sample code could be below were shapes holds your e.g. MultiPolygon
from shapely.geometry import mapping
import ezdxf
import ezdxf.addons.geo
doc = ezdxf.new()
geoproxy = ezdxf.addons.geo.GeoProxy.parse(mapping(shapes))
msp = doc.modelspace()
# Use LWPOLYLINE instead of hatch.
for entity in geoproxy.to_dxf_entities(polygon=2):
msp.add_entity(entity)
doc.saveas("test.dxf")
