# cf.FieldAncillary.id¶

FieldAncillary.id

An identity for the FieldAncillary object.

The id attribute can be used to unambiguously identify constructs. This can be useful when identification is not possible from the existing properties, either because they are missing or because they do not provide sufficiently unique information.

In general it will only be defined if explicitly set by the user.

Note that id is not a CF property and so is not read from, nor written to, datasets.

Examples:

>>> f.id = 'um01002'
>>> f.id
'um01002'
>>> f.match_by_identity('id%um10002')
True
>>> del f.id