Description
When creating a bag of bag I would expect a warning or confirmation if I really want to create a bag of a bag.
In general it should be possible to create a bag of a bag, but I would not consider it a default case.
Reproduction
bag = bagit.make_bag('/tmp/test_bag', {'Contact-Name': 'Thea'})
This creates a bag with all info, manifest files and the data directory
/tmp/test_bag
| - bag-info.txt
| - bagit.txt
| - data
| - manifest-sha256.txt
| - manifest-sha512.txt
| - tagmanifest-sha256.txt
| - tagmanifest-sha512.txt
If I run make_bag on the same folder again
bag_again = bagit.make_bag('/tmp/test_bag', {'Contact-Name': 'Thea})
this creates a bag with all info, manifest files and the data directory of the first level bag
/tmp/test_bag
| - bag-info.txt
| - bagit.txt
| - data
| - bag-info.txt
| - bagit.txt
| - data
| - manifest-sha256.txt
| - manifest-sha512.txt
| - tagmanifest-sha256.txt
| - tagmanifest-sha512.txt
| - manifest-sha256.txt
| - manifest-sha512.txt
| - tagmanifest-sha256.txt
| - tagmanifest-sha512.txt
Expection
I would expect a warning or even a confirmation, e.g.
>>> bag = bagit.make_bag('/tmp/test_bag', {'Contact-Name': 'Thea'})
>>> bag_again = bagit.make_bag('/tmp/test_bag', {'Contact-Name': 'Thea'})
WARNING: You are creating a bag of a bag. Do you want to continue? [N/y]
Realization
To achieve this behaviour we would need to detect, if a folder is already a bag.
One way could be to use the class constructor of Bag and catch the case for valid bag, but continue on Manifest not found.
Example for the make_bag function:
https://github.com/LibraryOfCongress/bagit-python/blob/master/bagit.py#L141C1-L143C3
def make_bag(
bag_dir, bag_info=None, processes=1, checksums=None, checksum=None, encoding="utf-8"
):
# ....
try:
bagit.Bag(bag_dir)
while True:
ans = input("WARNING: You are creating a bag of a bag. Do you want to continue? [N/y]")
if ans.lower() == 'y':
break
elif not ans or ans.lower() == 'n':
raise UserWarning('Aborted')
except Exception as e:
pass
# ...