Conduct Buffer Analysis in PyQGIS

Question

Given that I have 1 shapefiles for instance c:/users/user/line.shp
and I have activated my QGIS Console in Anaconda prompt

(base) $ conda activate qgis-venv
(qgis-venv) $ python
>>> import qgis
>>> #????

How should I put command in the console to execute buffer of 500?

score 3 · Accepted Answer · answered Mar 24 '22 at 14:49

You can try this :

import sys
from qgis.core import (
     QgsApplication, 
     QgsProcessingFeedback, 
     QgsVectorLayer
)
See https://gis.stackexchange.com/a/155852/4972 for details about the prefix
QgsApplication.setPrefixPath('/usr', True)
qgs = QgsApplication([], False)
qgs.initQgis()
Append the path where processing plugin can be found
sys.path.append('/docs/dev/qgis/build/output/python/plugins')
import processing
from processing.core.Processing import Processing
Processing.initialize()
vlayer = QgsVectorLayer('P:/Test/qgis_test/poly_test.shp', "poly_test", "ogr")
parameter_dictionary = {
    'INPUT' : vlayer,
    'DISTANCE' : 500,
    'SEGMENTS' : 25,
    'END_CAP_STYLE' : 0,
    'JOIN_STYLE' : 1,
    'MITER_LIMIT' : 10,
    'DISSOLVE' : False,
    'OUTPUT' : 'memory:'
    }
buffer_result = processing.run("native:buffer", parameter_dictionary)
output = buffer_result['OUTPUT']

Also do not forget to check the QGIS Documentation

References:

Conduct Buffer Analysis in PyQGIS

1 Answers1

See https://gis.stackexchange.com/a/155852/4972 for details about the prefix

Append the path where processing plugin can be found