Csdrhrt

Want to merge all shp files in a folder into one with a new field populated with the source filename. Not getting any errors but not getting any outputs.

Code originally taken from (How to add field with filename when merging shapefiles with ogr2ogr?)

# merge_shps.py

import os    

path = "C:TEMPSWS_SUDSCadastral_Maps"  # path to your folder of .shp files

merge = "SWS_INSPIRE"                         # this will be the name of your merged result

directory = os.listdir(path)

count = 0

for filename in directory:

    print "n" + filename + "n"

    if ".SHP" in filename.upper() and not ".XML" in filename.upper():

        # On the first pass, create a clone and add the filename column.

        if count == 0:

             # Make a clone (matt wilkie)..

             cmd = 'ogr2ogr ' + path + '\' + merge + '.shp ' + path + '\' + filename + ' -where "FID < 0"'

             print "n" + cmd + "n"

             os.system(cmd)

             # Add the field (j03lar50n)..

             cmd = 'ogrinfo ' + path + '\' + merge + '.shp -sql "ALTER TABLE ' + merge + ' ADD COLUMN filename character(50)"'

             print "n" + cmd + "n"

             os.system(cmd)

        # Now populate the data (capooti)..

        print "Merging: " + str(filename)

        # You'll need the filename without the .shp extension for the OGR_SQL..

        filenameNoExt = filename.replace(".shp","")

        cmd = 'ogr2ogr -f "esri shapefile" -update -append "' + 

         path + '\' + merge + '.shp" "' + 

         path + '\' + filename +'"' 

         ' -sql "SELECT '' + filename + '' AS filename, * FROM ' + filenameNoExt + '"'

        # Uncomment this line to spit the ogr2ogr sentence to the terminal..

        print "n" + cmd + "n"

        os.system(cmd)

        count += 1

I'd suggest you rather go with ogr2ogr in a terminal script directly.

In summary (using the syntax from the linked post), to merge all .shp into merged.shp (both in CWD), with the filename (without extension) added as a column, run from within

• 
  

  Bash (Linux):

  
  
  

  for file in *.shp
  
  do
  
    if [ -f  merged.shp ]
  
      then
  
        ogr2ogr -f "ESRI Shapefile" merged.shp $file -update -append -dialect "SQLite" -sql "SELECT '${file%.*}' AS filename, * FROM ${file%.*}"
  
      else
  
        ogr2ogr -f "ESRI Shapefile" merged.shp $file -dialect "SQLite" -sql "SELECT '${file%.*}' AS filename, * FROM ${file%.*}"
  
    fi
  
  done
  
  

  
  


• 
  

  CMD (Windows Command Line):

  
  
  

  for %F in (*.shp) do (
  
    if not exists merged.shp (
  
      ogr2ogr -f "ESRI Shapefile" merged.shp %F -dialect "SQLite" -sql "SELECT '%~nF' AS filename, * FROM %~nF"
  
    ) else (
  
      ogr2ogr -f "ESRI Shapefile" merged.shp %F -update -append -dialect "SQLite" -sql "SELECT '%~nF' AS filename, * FROM %~nF"
  
    )
  
  )
  
  

  
  

And to add up to this, there's actually no need to catch the non-existing file case, ogr2ogr will (at least in recent versions) create the file even in -append mode:

• 
  

  Bash (Linux):

  
  
  

  for file in *.shp
  
  do
  
    ogr2ogr -f "ESRI Shapefile" merged.shp $file -dialect "SQLite" -sql "SELECT '${file%.*}' AS filename, * FROM ${file%.*}"
  
  done
  
  

  
  


• 
  

  CMD (Windows Command Line):

  
  
  

  for %F in (*.shp) do (
  
    ogr2ogr -f "ESRI Shapefile" merged.shp %F -update -append -dialect "SQLite" -sql "SELECT '%~nF' AS filename, * FROM %~nF"
  
  )
  
  

  
  

Turns out the path to the ogr2ogr executable wasn't included in my Path environment variable... seems to work now.

Your question is tagged with qgis so I'm answering with QGIS, even if you show us only code with ogr2ogr.

In QGIS, you can use the tool Merge vector layers. Two attributes are added automatically, the filename and the filepath.

Then if you want to do the same in python, you can open the history of Processing commands (from the previous step above with Merge vector layer) and copy/paste the python line.

It gives:

processing.run("native:mergevectorlayers", {'LAYERS':['path/to/first/layer','path/to/second/layer'],'CRS':None,'OUTPUT':'memory:'})

It will create a memory layer.