I'm trying to run the following algorithm which runs fine when I select a layer I imported from the CSV file in question but not when I just try to run if from the file itself.

input = '/media/path/points.csv=csv&detectTypes=yes&xField=long&yField=lat&crs=EPSG:103172&spatialIndex=no&subsetIndex=no&watchFile=no'

layers = QgsProject.instance().mapLayersByName('points')
#input = layers[0]

output = '/media/path/outline.shp'

params = { 'DATE_FORMAT' : '', 'GROUP_FIELD' : 'rid', 'INPUT' : input, 'ORDER_FIELD' : 'vertex_ind', 'OUTPUT' : output }

res = processing.run('qgis:pointstopath', params)

I'm getting:

File "/usr/share/qgis/python/plugins/processing/core/Processing.py", line 137, in runAlgorithm raise QgsProcessingException(msg) _core.QgsProcessingException: Unable to execute algorithm Could not load source layer for INPUT: /media/path/points.csv=csv&detectTypes=yes&xField=long&yField=lat&crs=EPSG:103172&spatialIndex=no&subsetIndex=no&watchFile=no not found

  • 1
    Try replacing layers = QgsProject.instance().mapLayersByName('points') with layers = QgsVectorLayer("file:///" + input, "point", "delimitedtext") and then replace 'INPUT' : input with 'INPUT' : layers in params. – Joseph Aug 12 '19 at 14:36
  • This seems to get me closer, it looks to be reading the file but now I'm getting: TypeError: 'QgsVectorLayer' object is not subscriptable – Sean Aug 12 '19 at 16:52

With Joseph's insight this is what worked.

input_uri = 'file:////media/path/points.csv?delimiter=,&xField=long&yField=lat&crs=espg:103172&spatialIndex=no&subsetIndex=no&watchFile=no'
output_uri = '/media/spath/out_paths.shp'
lyr = QgsVectorLayer(input_uri, 'New CSV','delimitedtext')

params = { 'DATE_FORMAT' : '', 'GROUP_FIELD' : 'rid', 'INPUT' : lyr, 'ORDER_FIELD' : 'vertex_ind', 'OUTPUT' : output_uri }
res = processing.run('qgis:pointstopath', params)

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