Interpreting metadata#
Many client functions return metadata. This class includes information about what objects records were created or already existing on the server, or which objects were deleted, modified, or had errors.
All metadata objects have some common features. Notably, if the operation was completely successful operation,
then meta.success will be True. If any errors happened, these are also stored in meta.errors and
meta.success will be False.
Metadata classes also have fields with an _idx suffix. These are lists that reference the
zero-based index of the input list. If we take molecules as an example,
>>> water = Molecule(symbols=['H', 'H', 'O'], geometry=[0.0, 2.0, 0.0, 2.0, 0.0, 0.0, 0.0, 0.0, 0.0])
>>> nitrogen = Molecule(symbols=['N', 'N'], geometry=[0.0, 0.0, 0.0, 0.0, 0.0, 2.0])
>>> meta, ids = client.add_molecules([water, nitrogen])
>>> print(meta.success)
True
>>> print(meta)
InsertMetadata(error_description=None, errors=[], inserted_idx=[0], existing_idx=[1])
In this case, the addition of the two molecules to the server was a success. The first molecule water
did not exist and was added to the server - this is represented by 0 in the inserted_idx attribute
of the metadata. Likewise, the nitrogen molecule already existed (because 1 is in the existing_idx list).
If the water molecule already existed as well, inserted_idx would be [] and existing_idx would be
[0, 1].
The total number of inserted or existing objects can be retrieved with n_inserted and n_existing.