# cf.Field.replace_construct¶

Field.replace_construct(identity, construct, copy=True)[source]

Parameters: identity: Select the metadata construct to be replaced by one of: The identity or key of a metadata construct. The identity or key of a domain axis construct that is spanned by a metadata construct’s data. A construct identity is specified by a string (e.g. 'latitude', 'long_name=time', 'ncvar%lat', etc.); a Query object (e.g. cf.eq('longitude')); or a compiled regular expression (e.g. re.compile('^atmosphere')) that selects the relevant constructs whose identities match via re.search. A 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. 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='Y' Parameter example: identity='latitude' Parameter example: identity='long_name=Latitude' Parameter example: identity='dimensioncoordinate1' Parameter example: identity='domainaxis2' Parameter example: identity='ncdim%y' construct: The new construct to replace that selected by the identity parameter. copy: bool, optional If True then set a copy of the new construct. By default the construct is not copied. The construct that was replaced.
>>> f.replace_construct('X', new_X_construct)