How can I avoid UnicodeEncodeError when using geoprocessing tools in QGIS?

Question

I have a shapefile, that I want to split with the "Split Layers by Field"-tool. Due to some umlauts (ä,ü,ö) there will be a python error as soon, as the tool reaches a feature with an umlaut. The following error message will appear:

*An error has occured while executing Python code: Traceback (most recent call last): File "C:/Users/Gidi/.qgis//python/plugins\layers_by_field\layers_by_field_dialog.py", line 58, in accept self.split( inLayer, inField ) File "C:/Users/Gidi/.qgis//python/plugins\layers_by_field\layers_by_field_dialog.py", line 146, in split self.vlayer = QgsVectorLayer(vProvider.dataSourceUri(), str(layer.name()) + "_" + str(uValues[j]), "ogr") UnicodeEncodeError: 'ascii' codec can't encode character u'\xfc' in position 7: ordinal not in range(128) Python version: 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)] QGIS version: 1.8.0-Lisboa Lisboa, 6416f38 Python path: ['C:/PROGRA~2/Quantum GIS Lisboa/apps/qgis/./python', 'C:/Users/Gidi/.qgis//python', 'C:/Users/Gidi/.qgis//python/plugins', 'C:/PROGRA~2/Quantum GIS Lisboa/apps/qgis/./python/plugins', 'C:\PROGRA~2\Quantum GIS Lisboa\bin\python27.zip', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\DLLs', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\plat-win', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\lib-tk', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\qgis\bin', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\PIL', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\win32', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\win32\lib', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\Pythonwin', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\wx-2.8-msw-unicode', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\qgis\python\plugins\fTools\tools']*

What can I do to avoid this error? I do not want to change the name of every feature and would prefer the umlauts to remain in my shapefile.

• Matthias Kuhn: Are you writing your own plugin or is this a plugin from someone else?
• Gideon: It is a plugin, that can be intalled diectly in QGIS via the Plugin Extension Manager.

Answer 1

The problem is in the python code. The following line of the error message highlights the problem:

"C:/Users/Gidi/.qgis//python/plugins\layers_by_field\layers_by_field_dialog.py", line 146, in split self.vlayer = QgsVectorLayer(vProvider.dataSourceUri(), str(layer.name()) + "_" + str(uValues[j]), "ogr") UnicodeEncodeError: 'ascii' codec can't encode character u'\xfc' in position 7: ordinal not in range(128) Python version: 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)] QGIS

The method str() is used there to generate a string. Instead, the method unicode() should be used to generate a unicode string. Note: this only applies to QGIS 2, starting from QGIS 3 this no longer is applicable due to the usage of Python 3 where str already is unicode by default.

self.vlayer = QgsVectorLayer( vProvider.dataSourceUri(), unicode(layer.name()) + "_" + unicode(uValues[j]), u'ogr')

If it is not your own plugin, please file a bug or contact the author.

Edit: I just checked.Here is the link to the bugtracker for this plugin.

• Gideon: Thank you! Do you think it will be possible for me to fix the plugin for my personal use without specific pythonskills?
• Matthias Kuhn: It should be pretty easy and straightforward by just replacing str with unicode on any line which gives the error mentioned in the answer. Please still open a bug (and link to this question here), so other people won't suffer from the same problem.
• Gideon: Thank you once again, I will try it as soon as I can and also open the bug.