18 Feb 2015

Python Processing Script for Splitting Layer and Saving each Feature to Shapefile

A script for a common task: Split a Layer by distinct values of an attribute-field. The script will use the value for the name of the files and remove the field from the new files.

Put this processing script to the appropiate director (in my case it's "C:\Users\Kay\.qgis2\processing\scripts") to make it work. Then it will be easily accessible from your processing toolbox.

##[User scripts]=group
##input=vector
##class_field=field input
##output=output file

from qgis.core import *
from PyQt4.QtCore import *
from processing.core.VectorWriter import VectorWriter

layer = processing.getObject(input)
provider = layer.dataProvider()
fields = provider.fields()
class_field_index = layer.fieldNameIndex(class_field)

fields.remove( class_field_index )

inFeat = QgsFeature()
outFeat = QgsFeature()
inGeom = QgsGeometry()
nElement = 0
writers = {}

feats = processing.features(layer)
nFeat = len(feats)

for inFeat in feats:
    progress.setPercentage(int(100 * nElement / nFeat))
    nElement += 1
    featAttr = inFeat.attributes()
    classField = featAttr[class_field_index]

    if classField not in writers:
        outputFile = output + '_' + classField + '.shp'
        writers[classField] = VectorWriter(outputFile, None, fields, provider.geometryType(), layer.crs())
        
    inGeom = inFeat.geometry()
    outFeat.setGeometry(inGeom)
    
    del featAttr[class_field_index]
    outFeat.setAttributes(featAttr)
        
    writers[classField].addFeature(outFeat)

for writer in writers.values():
    del writer

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