music21.converter.parse() fails if the input compressed MusicXML (MXL) contains only one XML file with filename exactly as ".xml"

[dszeto]

music21 version

9.9.1

Operating System(s) checked
macOS, Linux (platform-agnostic issue)

Problem summary

When music21.converter.parse opens a compressed MusicXML (MXL) that contains only one XML file with the filename exactly as .xml, it throws an exception. Upon further investigation, the line at

music21/music21/converter/__init__.py

Line 213 in e461154

if pathlib.Path(subFp).suffix not in ['.musicxml', '.xml', '.mxl']:

fails to include .xml because .suffix returns an empty string for .xml.

Steps to reproduce

First, use Noteflight to produce an MXL file (because they consistently produce MXL files with this issue), then simply

import music21

music21.converter.parse("mxl.mxl")

will throw an exception.

More information

A quick fix would be to also match file extensions as is as extra testing conditions.

[mscuthbert]

Got it, so you're saying that if I have a score like "Flute Piece.mxl" and inside it is a single score called just ".xml" with nothing except the suffix, then music21 won't read it?

Got it, will fix esp. since I can reproduce --

This only happens in Noteflight if the score has no title -- the workaround until there is a new release is to always give your noteflight scores titles before exporting. Since there is an easy workaround, I don't plan on back-porting this to 9.9 but it'll need to wait till 10.0 comes out.

THANKS!

[mscuthbert]

Fixed in #1834

[dszeto]

That was quick. Thank you so much!