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()

---

Example:

Sample points:

Sample points

Result:

Results

• Abhijit Gujar: what if i want all the buffers in one layer and not a separate layer for each buffer ?
• Joseph: @AbhijitGujar - Just run processing.runandload("qgis:fixeddistancebuffer", layer, 0.01, 99, False, None) without a for loop :)
• Abhijit Gujar: Thanks but what i want is to make buffer for 1000 features but i certainly don't want 1000 buffers in layer panel but i need all 1000 buffers in one layer
• Joseph: @AbhijitGujar - Could you ask this as a new question please? I'm not sure I follow. Also include any code you have used :)