How to amend Python code to work in QGIS 3?

Question

In another thread, I was given this code to import large numbers of dxfs into QGIS. This code works in QGIS2.18, but they just released QGIS 3.0 and have changed the codes to use a different version of Python. This code doesn't work in 3.0. Running it generates a series of requests to set the CRS, but nothing then imports.

How can I edit this code (or other codes) to be compatible with QGIS 3.0? What was changed? I tried an online converter but it didn't alter anything.

import glob, os
path = "E:/aawork/aasites/aa-all towns and villages/Hemelhempstead/osmap 2012/"
for layer in glob.glob(path + "*.dxf"):
 vlayer = QgsVectorLayer(layer, 'name', 'ogr')
 subLayers = vlayer.dataProvider().subLayers()
 for subLayer in subLayers:
 geom_type = subLayer.split(':')[-1]
 if geom_type == 'LineString':
 uri = "%s|layername=entities|geometrytype=%s" % (layer, geom_type,)
 dfx_file_name = os.path.splitext(os.path.basename(layer))[0]
 layer_name = "%s - %s" % (dfx_file_name,geom_type,)
 sub_vlayer = QgsVectorLayer(uri, layer_name, 'ogr')
 QgsMapLayerRegistry.instance().addMapLayer(sub_vlayer)

• Mike -EZUSoft-: Btw: Test the PlugIn Another DXF Importer / DXF2Shape Converter Multiple files can be imported at the same time (batch import). One click for a lot of files.

Answer 1

You could try the following:

import glob, os
path = "E:/aawork/aasites/aa-all towns and villages/Hemelhempstead/osmap 2012/"
for layer in glob.glob(path + "*.dxf"):
 vlayer = QgsVectorLayer(layer, 'name', 'ogr')
 subLayers = vlayer.dataProvider().subLayers()
 for subLayer in subLayers:
 if 'Point' in subLayer:
 uri = "%s|layername=entities|geometrytype=Point" % (layer)
 if 'LineString' in subLayer:
 uri = "%s|layername=entities|geometrytype=LineString" % (layer)
 dfx_file_name = os.path.splitext(os.path.basename(layer))[0]
 sub_vlayer = QgsVectorLayer(uri, dfx_file_name, 'ogr')
 QgsProject.instance().addMapLayer(sub_vlayer)

---

For the CRS, you could set a specific one as default when loading your dxf files which can be done from the the menubar:

Settings > Options > CRS > CRS for new layers

• PJ Lightning: That's already done. It doesn't enable the code to work. Apparently Python has changed how the separators work, but I don't know how they changed them.
• PJ Lightning: OK, I tried the amended version and checked that the CRS is set to default, but it's still asking me for a crs for each and every one of the dxfs in that folder. That's a lot of dxfs. The set to default doesn't seem to affect the dxf import.
• Joseph: @PJLightning - I can't replicate your issue. Are you using the official release version? The version I have is 3.0.0-Girona (you can check this from the menubar Help > About).
• PJ Lightning: Another dxf converter does work for small numbers of dxfs, but it's about ten times slower than the python code. It's not a great option for large areas. It did import the dxfs eventually, though, which I guess is the main thing.
• PJ Lightning: Oh wait! I thought I'd set a default crs, but I'd set it for the project, not for the layers. It's working. I'll select your code as the answer. Thank you.