Creating temporary buffer layer in QGIS?

Question

I have been able to select features using an attribute from a Point vector file:

expr = QgsExpression("\"NAME\" = 'PESCOE'") 
collegePoint = collegeLayer.getFeatures( QgsFeatureRequest (expr))

#get ids  
ids = [i.id() for i in collegePoint]

#select the features  
collegeLayer.setSelectedFeatures(ids)

Now for each of the selected features I wish to create a temporary buffer layer (not as presented in Buffering in pyQGIS?, as it is not quite clear).

How do I achieve this?

Answer 1

You could use the following which:

1. Creates a list of your selected features.
2. Clears the selection.
3. Iterates through each feature in the list, selects it and runs the processing buffer algorithm.
4. Each buffer is a temporary output which are immediately loaded.

Note that the "Use only selected features" option must be enabled in:

Processing > Options > General > Use only selected features

Here is the code:

import processing
layer = iface.activeLayer()
feat_list = []
for feat in layer.selectedFeatures():
    feat_list.append(feat)

layer.removeSelection()

for selected_feat in feat_list:
    layer.select( selected_feat.id() )
    processing.runandload("qgis:fixeddistancebuffer", layer, 0.01, 99, False, None)
    layer.removeSelection()

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Example:

Sample points:

Result: