cfdm.Constructs

---

class cfdm.Constructs(auxiliary_coordinate=None, dimension_coordinate=None, domain_ancillary=None, field_ancillary=None, cell_measure=None, coordinate_reference=None, domain_axis=None, cell_method=None, source=None, copy=True, _use_data=True, _view=False, _ignore=())

Bases: cfdm.mixin.container.Container, cfdm.core.constructs.Constructs

A container for metadata constructs.

The container has similarities to a dict in that it presents the metadata constructs as key/value pairs, where the key is the unique identifier that corresponds to a metadata construct value; is indexable by metadata construct identifier; and provides a subset of the usual dictionary methods: get, items, keys, and values. The number of constructs (which may be zero) can be found via the Python len function. The container can be converted to an actual dict with the todict method.

Filtering

A subset of the metadata constructs can be defined and returned in a new Constructs instance by using the various filter methods. See filter for more details.

Calling

Calling a Constructs instance also creates a new Constructs instance that contains a subset of the metadata constructs, primarily selecting by construct identity. For instance, selecting constructs that have an identity of ‘latitude’ could be done by either x = c('latitude') or x = c.filter_by_identity('latitude'). More generally, c(*identities, **filter_kwargs) is equivalent to c.filter(filter_by_identity=identities, **filter_kwargs).

Metadata constructs

The following metadata constructs can be included:

• auxiliary coordinate constructs

• coordinate reference constructs

• cell measure constructs

• dimension coordinate constructs

• domain ancillary constructs

• domain axis constructs

• cell method constructs

• field ancillary constructs

New in version (cfdm): 1.7.0

Initialisation

Parameters

auxiliary_coordinate: str, optional

The base name for keys of auxiliary coordinate constructs.

Parameter example:

auxiliary_coordinate='auxiliarycoordinate'

dimension_coordinate: str, optional

The base name for keys of dimension coordinate constructs.

Parameter example:

dimension_coordinate='dimensioncoordinate'

domain_ancillary: str, optional

The base name for keys of domain ancillary constructs.

Parameter example:

domain_ancillary='domainancillary'

field_ancillary: str, optional

The base name for keys of field ancillary constructs.

Parameter example:

field_ancillary='fieldancillary'

cell_measure: str, optional

The base name for keys of cell measure constructs.

Parameter example:

cell_measure='cellmeasure'

coordinate_reference: str, optional

The base name for keys of coordinate reference constructs.

Parameter example:

coordinate_reference='coordinatereference'

domain_axis: str, optional

The base name for keys of domain axis constructs.

Parameter example:

domain_axis='domainaxis'

cell_method: str, optional

The base name for keys of cell method constructs.

Parameter example:

cell_method='cellmethod'

source: optional

Convert source, which can be any type of object, to a Constructs instance.

All other parameters, apart from copy, are ignored and their values are instead inferred from source by assuming that it has the Constructs API. Any parameters that can not be retrieved from source in this way are assumed to have their default value.

Note that if x is also a Constructs instance then cfdm.Constructs(source=x) is equivalent to x.copy().

copy: bool, optional

If True (the default) then deep copy metadata constructs from those of source prior to initialisation, else they are not deep copied.

_ignore: sequence of str, optional

Ignores the given construct types.

Parameter example:

_ignore=('cell_method', 'field_ancillary')

Filtering

Methods

filter_by_identity	Select metadata constructs by identity.
filter_by_property	Select metadata constructs by property.
filter_by_measure	Select cell measure constructs by measure.
filter_by_method	Select cell method constructs by method.
filter_by_axis	Select metadata constructs by axes spanned by their data.
filter_by_naxes	Selects constructs by the number of axes their data spans.
filter_by_size	Select domain axis constructs by size.
filter_by_data	Selects metadata constructs that could contain data.
filter_by_type	Select metadata constructs by type.
filter_by_key	Select metadata constructs by key.
filter_by_ncdim	Select domain axis constructs by netCDF dimension name.
filter_by_ncvar	Select domain axis constructs by netCDF variable name.
filter	Select metadata constructs by a chain of filters.
domain_axes	Return domain axis constructs.
filters_applied	A history of filters that have been applied.
clear_filters_applied	Remove the history of filters that have been applied.
inverse_filter	Return the inverse of previous filters.
unfilter	Return the constructs that existed prior to previous filters.

Constructs and identifiers

Methods

key	Return the construct key of the sole metadata construct.
value	Return the sole metadata construct.
construct_type	Return the type of a construct for a given key.
construct_types	Return all of the construct types for all keys.
domain_axis_identity	Return the canonical identity for a domain axis construct.
new_identifier	Return a new, unused construct key.

Data axes

Methods

data_axes	Returns the axes spanned by the data.
get_data_axes	Return the keys of the axes spanned by a construct’s data.

Miscellaneous

Methods

copy	Return a deep copy.
shallow_copy	Return a shallow copy.
equals	Whether two Constructs instances are the same.
replace	Replace one metadata construct with another.
todict	Return a dictionary of the metadata constructs.
ordered	Return the constructs in their predetermined order.

Dictionary-access methods

Methods

get	Returns the construct for the key, else default.
items	Return the items as (construct key, construct) pairs.
keys	Return all of the construct keys, in arbitrary order.
values	Return all of the metadata constructs, in arbitrary order.
__getitem__	Return a construct with the given key.

Special

Methods

__call__	Select metadata constructs by identity.
__contains__	Implements membership test operators for construct keys.
__copy__	Called by the copy.copy standard library function.
__deepcopy__	Called by the copy.deepcopy standard library function.
__getitem__	Return a construct with the given key.
__iter__	Called when an iterator is required.
__len__	Return the number of constructs.
__repr__	Called by the repr built-in function.
__str__	Called by the str built-in function.

Docstring substitutions

Methods

_docstring_special_substitutions	Return the special docstring substitutions.
_docstring_substitutions	Returns the substitutions that apply to methods of the class.
_docstring_package_depth	Returns the class {{package}} substitutions package depth.
_docstring_method_exclusions	Returns method names excluded in the class substitutions.