Test filelist databases when no zt files exist

@mguenther is this a bug? I cannot call db.all_files on file list based databases with no ztnorm files.

That is most probably a bug. I'll have a look at it.

assigned to @mguenther

When having a look into the all_files function, you can clearly see that there is an add_zt_files=True option: https://gitlab.idiap.ch/bob/bob.bio.base/blob/45983b2d464abbf257e91746c91cfdc22d1c7f96/bob/bio/base/database/filelist/query.py#L204

Your test case is, hence, wrong.

I know why it happens. Don't you think it's counter intuitive when you simply call db.all_files() it raises an exception? I am trying to use the database API outside bob.bio.base here. This filelist based database is trying to satisfy two datasets one with ztnorm and one without ztnorm. Can it issue a warning instead of raising an exception? or can we have something better that doesn't crash?

I tried to check, what is the default for databases that come with ZT files by default, such as bob.db.mobio. Unfortunately, the all_files option seems not to be present in this low-level dataset.

I could automatically add the zt_files if they are available, and have the option working the other way round: remove_zt_files=False. Then, I can issue a warning when this is set to True and no zt-files are there.

Having a look into how this function is used, I am afraid however that this would require more changes. We currently query the database.all_files() in the FileSelector: https://gitlab.idiap.ch/bob/bob.bio.base/blob/45983b2d464abbf257e91746c91cfdc22d1c7f96/bob/bio/base/tools/FileSelector.py#L113 This has lately been introduced to solve #67 (closed).

Anyways, the default implementation of all_files in bob.bio.base.databse.ZTBioDatabase uses the same flag: https://gitlab.idiap.ch/bob/bob.bio.base/blob/45983b2d464abbf257e91746c91cfdc22d1c7f96/bob/bio/base/database/database.py#L645 which is True by default. When you accidentally derive your high-level class from ZTBioDatabase without providing ZT files, you get a similar error.

So, this comes back to your suggestion, i.e., turning the exception into a warning. Yes, this should be possible. I will implement a patch.

added 1 commit

• 6c92c1ce - Turned exception of missing ZT files into a warning

Compare with previous version

assigned to @amohammadi

mentioned in commit 24f53216

merged

I clicked on the merge button. Thanks @mguenther for the patch.