# cf.Field.domain_axis¶

Field.domain_axis(identity, key=False, default=ValueError())[source]

Return a domain axis construct, or its key.

New in version 3.0.0.

Parameters: identity: Select the domain axis construct by one of: An identity or key of a 1-d coordinate construct that whose data spans the domain axis construct. A domain axis construct identity or key. The position of the domain axis construct in the field construct’s data. A construct identity is specified by a string (e.g. 'latitude', 'long_name=time', 'ncvar%lat', etc.); or a compiled regular expression (e.g. re.compile('^atmosphere')) that selects the relevant constructs whose identities match via re.search. Each construct has a number of identities, and is selected if any of them match any of those provided. A construct’s identities are those returned by its identities method. In the following example, the construct x has six identities: >>> x.identities() ['time', 'long_name=Time', 'foo=bar', 'standard_name=time', 'ncvar%t', 'T']  A construct key may optionally have the 'key%' prefix. For example 'dimensioncoordinate2' and 'key%dimensioncoordinate2' are both acceptable keys. A position of a domain axis construct in the field construct’s data is specified by an integer index. Note that in the output of a print call or dump method, a construct is always described by one of its identities, and so this description may always be used as an identity argument. Parameter example: identity='long_name=Latitude' Parameter example: identity='dimensioncoordinate1' Parameter example: identity='domainaxis2' Parameter example: identity='key%domainaxis2' Parameter example: identity='ncdim%y' Parameter example: identity=2 key: bool, optional If True then return the selected construct key. By default the construct itself is returned. default: optional Return the value of the default parameter if a construct can not be found. If set to an Exception instance then it will be raised instead. DomainAxis or str` The selected domain axis construct, or its key.

Examples:

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