Publishers who publish records electronically without having finalized a given issue/volume may have either blank or zero values for the issue and volume. With this PR, those cases will no longer have the value "None" in the keys for issue and volume; the keys simply won't be there.
Also, in at least one case, a publisher provided an electronic article with pagecount: 0. These (rare) cases will also not be propagated to the output JSON.
Publishers who publish records electronically without having finalized a given issue/volume may have either blank or zero values for the issue and volume. With this PR, those cases will no longer have the value "None" in the keys for issue and volume; the keys simply won't be there.
Also, in at least one case, a publisher provided an electronic article with
pagecount: 0. These (rare) cases will also not be propagated to the output JSON.