Add multiple rasters using QgsRasterLayer with for loop

Question

I am trying to create a for loop for coloring up multiple rasters simultaneously. I am able to do it for one layer, but trying to implement the for loop to do it for more than one layer is proving difficult.

import glob,os
rast_path="/home/user/Desktop/data/gsi/output"
rasters=glob.glob(os.path.join(rast_path,"*le.tif"))
print(rasters)
for raster in rasters:
# (rastdir,rastfile)=os.path.split(raster)
 lyr=QgsRasterLayer(rasters,rastfile)
 s=QgsRasterShader()
 c=QgsColorRampShader()
 c.setColorRampType(QgsColorRampShader.INTERPOLATED)
 i=[]
 i.append(QgsColorRampShader.ColorRampItem(-20,QtGui.QColor('#0c0101'),'-20'))
 i.append(QgsColorRampShader.ColorRampItem(-15.1,QtGui.QColor('#ff0000'),'-15'))
 i.append(QgsColorRampShader.ColorRampItem(-10,QtGui.QColor('#ff0000'),'-10'))
 i.append(QgsColorRampShader.ColorRampItem(-5,QtGui.QColor('#ff0000'),'-5'))
 i.append(QgsColorRampShader.ColorRampItem(0,QtGui.QColor('#ff0000'),'0'))
 i.append(QgsColorRampShader.ColorRampItem(5,QtGui.QColor('#ff0000'),'5'))
 i.append(QgsColorRampShader.ColorRampItem(10,QtGui.QColor('#ff0000'),'10'))
 i.append(QgsColorRampShader.ColorRampItem(15,QtGui.QColor('#ff0000'),'15'))
 i.append(QgsColorRampShader.ColorRampItem(15,QtGui.QColor('#0c0101'),'20'))
 c.setColorRampItemList(i)
 s.setRasterShaderFunction(c)
 ps=QgsSingleBandPseudoColorRenderer(lyr.dataProvider(),1,s)
 raster.setRenderer(ps)
 QgsMapLayerRegistry.instance().addMapLayer(lyr)
# qgis.utils.iface.addRasterLayer(raster,rastfile)

• Spacedman: Where's your for loop? What have you tried? Where exactly are you stuck?
• user1655130: @Spacedman, Sorry code updated there now.

Answer 1

I prefer adding rasters described from the QGIS docs which I've incorporated into your script in addition to importing a couple more required classes:

import glob, os
from PyQt4 import QtGui
from PyQt4.QtCore import QFileInfo
rast_path = "/home/user/Desktop/data/gsi/output"
rasters = glob.glob(os.path.join(rast_path, "*le.tif"))
print(rasters)
for raster in rasters:
 fileInfo = QFileInfo(raster)
 path = fileInfo.filePath()
 baseName = fileInfo.baseName()
 lyr = QgsRasterLayer(path, baseName)
 s = QgsRasterShader()
 c = QgsColorRampShader()
 c.setColorRampType(QgsColorRampShader.INTERPOLATED)
 i = []
 i.append(QgsColorRampShader.ColorRampItem(-20,QtGui.QColor('#0c0101'),'-20'))
 i.append(QgsColorRampShader.ColorRampItem(-15.1,QtGui.QColor('#ff0000'),'-15'))
 i.append(QgsColorRampShader.ColorRampItem(-10,QtGui.QColor('#ff0000'),'-10'))
 i.append(QgsColorRampShader.ColorRampItem(-5,QtGui.QColor('#ff0000'),'-5'))
 i.append(QgsColorRampShader.ColorRampItem(0,QtGui.QColor('#ff0000'),'0'))
 i.append(QgsColorRampShader.ColorRampItem(5,QtGui.QColor('#ff0000'),'5'))
 i.append(QgsColorRampShader.ColorRampItem(10,QtGui.QColor('#ff0000'),'10'))
 i.append(QgsColorRampShader.ColorRampItem(15,QtGui.QColor('#ff0000'),'15'))
 i.append(QgsColorRampShader.ColorRampItem(15,QtGui.QColor('#0c0101'),'20'))
 c.setColorRampItemList(i)
 s.setRasterShaderFunction(c)
 ps = QgsSingleBandPseudoColorRenderer(lyr.dataProvider(),1,s)
 lyr.setRenderer(ps)
 QgsMapLayerRegistry.instance().addMapLayer(lyr)

Result

• user1655130: Excellent. This works perfect
• Joseph: @user1655130 - Awesome, glad it works :)