File objects with no tags cast to boolean as false

[Clarence "Sparr" Risher]

True if mutagen.File("foo.ogg") else False

This will evaluate to False if foo.ogg contains no id3 tags. I believe this is because the mutagen file types do not have a __bool__ method, so the implicit boolean cast falls back on __len__ which ends up referring to the number of keys in the DictProxy for the file's id3 tags.

While I could work around this by explicitly checking for None vs a file type instance, I think it would be reasonable to expect the type to cast to True when it has successfully loaded a file.