TypeError: argument of type 'NoneType' is not iterable

[mikegerber]

With this input (full workspace: qurator-spk/sbb_binarization#8 (comment)):

<?xml version="1.0" encoding="UTF-8"?>
<pc:PcGts xmlns:pc="http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15 http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15/pagecontent.xsd" pcGtsId="OCR-D-IMG-BIN_00000024">
    <pc:Metadata>
        <pc:Creator>OCR-D/core 2.18.1</pc:Creator>
        <pc:Created>2020-10-22T18:49:34.729618</pc:Created>
        <pc:LastChange>2020-10-22T18:49:34.729618</pc:LastChange>
        <pc:MetadataItem type="processingStep" name="preprocessing/optimization/binarization" value="ocrd-sbb-binarize">
            <pc:Labels externalModel="ocrd-tool" externalId="parameters">
                <pc:Label value="/var/lib/sbb_binarization" type="model"/>
                <pc:Label value="page" type="operation_level"/>
            </pc:Labels>
        </pc:MetadataItem>
    </pc:Metadata>
    <pc:Page imageFilename="OCR-D-IMG/OCR-D-IMG_00000024.tif" imageWidth="2463" imageHeight="4060">
        <pc:AlternativeImage filename="OCR-D-IMG-BIN/OCR-D-IMG-BIN_00000024.IMG-BIN.png"/>
    </pc:Page>
</pc:PcGts>

I get:

18:52:44.963 INFO processor.OcrdSbbTextlineDetectorRecognize - INPUT FILE 0 / <OcrdFile fileGrp=OCR-D-IMG-BIN, ID=OCR-D-IMG-BIN_00000024, mimetype=application/vnd.prima.page+xml, url=OCR-D-IMG-BIN/OCR-D-IMG-BIN_00000024.xml, local_filename=OCR-D-IMG-BIN/OCR-D-IMG-BIN_00000024.xml]/> 
Traceback (most recent call last):
  File "/usr/local/bin/ocrd-sbb-textline-detector", line 8, in <module>
    sys.exit(ocrd_sbb_textline_detector())
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/qurator/sbb_textline_detector/ocrd_cli.py", line 32, in ocrd_sbb_textline_detector
    return ocrd_cli_wrap_processor(OcrdSbbTextlineDetectorRecognize, *args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/ocrd/decorators/__init__.py", line 81, in ocrd_cli_wrap_processor
    run_processor(processorClass, ocrd_tool, mets, workspace=workspace, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/ocrd/processor/helpers.py", line 68, in run_processor
    processor.process()
  File "/usr/local/lib/python3.6/dist-packages/qurator/sbb_textline_detector/ocrd_cli.py", line 67, in process
    feature_filter='binarized,grayscale_normalized'
  File "/usr/local/lib/python3.6/dist-packages/ocrd/workspace.py", line 423, in image_from_page
    for feature in feature_filter.split(',') if feature)):
  File "/usr/local/lib/python3.6/dist-packages/ocrd/workspace.py", line 423, in <genexpr>
    for feature in feature_filter.split(',') if feature)):
TypeError: argument of type 'NoneType' is not iterable

@kba Might be a bug in OCR-D/core?

[mikegerber]

I believe it's due to the missing AlternativeImage/@comments qurator-spk/sbb_binarization#8, but I could be wrong.

[kba]

Both the underlying issue qurator-spk/sbb_binarization#8 and core not being able to handle AlternativeImage without comments should be fixed.

[mikegerber]

I guess this can be closed.