When calling the downloadAttachment method of the PartShop class to download a GFF attachment from SynBioHub, the result is a file that is much smaller than the original and does not appear to UTF-8 encoded.
The following code is an example of trying to download a GFF attachment for the SD2 instance of SynBioHub as described above.
part_shop = PartShop(https://hub.sd2e.org)
part_shop.login(sd2e, SD2_PASSWORD)
part_shop.downloadAttachment('https://hub.sd2e.org/user/sd2e/upload_sandbox/attachment_0f71ec67b1ad4d7ca0109d10ef564d35/1', '.')