As part of a bit of work updating PyDicomfrom 0.x to 1.x, I came across a number of AttributeErrors: AttributeError: 'FileDataset' object has no attribute 'ImagePathFilterTypeStackCodes'

The Dicoms are the same, and the error message are always in the same format (with a missing Dicom tag that it could find before) so the problem must be with PyDicom. (Note: this is assuming the tag isn’t a private tag. This is also new behaviour: you can search for a Dicom by its ID instead of its name)

Turns out there’s a change in PyDicom which removed a specific bit of code:

# Take "Sequence" out of name (pydicom < 0.9.7)
# e..g "BeamSequence"->"Beams"; "ReferencedImageBoxSequence"->"ReferencedImageBoxes"
# 'Other Patient ID' exists as single value AND as sequence so check for it and leave 'Sequence' in
if dictionaryVR(tag) == "SQ" and not s.startswith("OtherPatientIDs"):
    if s.endswith("Sequence"):
        s = s[:-8] + "s"
    if s.endswith("ss"):
        s = s[:-1]
    if s.endswith("xs"):
        s = s[:-1] + "es"
    if s.endswith("Studys"):
        s = s[:-2] + "ies"
return s

(inside method CleanName() – lines 134-146 in the version we were using, for those who want to find it)

That means, if our code was looking for the attribute ReferencedImageBoxSequence, then you could also search for ReferencedImageBoxes, and they’re both copies of the same Dicom tag data.

The fix? Unfortunately it’s a labourous one: you need to go through the test code, see which ones work and which don’t, and change them. This might be a task you can automate using grep, but it might also just be quicker to do it manually.