I don't understand why if I do "manually" some algorithms I get results much faster than when I insert the same in a pyqgis code (with the same input).
This happens, for example, with the
extract nodes algorithm.
I wrote a code in which I call the algorithm as follows:
p=processing.runalg('qgis:extractnodes', polylayer, None) points = processing.getObject(p['OUTPUT'])
The whole process slows down considerably during the execution of this algorithm (which appears on the top bar, so I am sure that the problem is right on the
extract nodes), taking about an hour for provide a result that I would normally be able to achieve in a few seconds.