cfdm.Index

---

class cfdm.Index(properties=None, data=None, source=None, copy=True, _use_data=True)

Bases: cfdm.mixin.netcdf.NetCDFVariable, cfdm.mixin.netcdf.NetCDFDimension, cfdm.mixin.netcdf.NetCDFSampleDimension, cfdm.mixin.propertiesdata.PropertiesData, cfdm.mixin.files.Files, cfdm.core.abstract.propertiesdata.PropertiesData

An index variable required to uncompress a ragged array.

A collection of features stored using an indexed ragged array combines all features along a single dimension (the sample dimension) such that the values of each feature in the collection are interleaved.

The information needed to uncompress the data is stored in an index variable that specifies the feature that each element of the sample dimension belongs to.

NetCDF interface

The netCDF variable name may be accessed with the nc_set_variable, nc_get_variable, nc_del_variable, and nc_has_variable methods.

The netCDF variable group structure may be accessed with the nc_set_variable, nc_get_variable, nc_variable_groups, nc_clear_variable_groups, and nc_set_variable_groups methods.

The name of the netCDF dimension spanned by the index variable’s data (which does not correspond to a domain axis construct) may be accessed with the nc_set_dimension, nc_get_dimension, nc_del_dimension, and nc_has_dimension methods.

The name of the netCDF sample dimension spanned by the compressed data (which does not correspond to a domain axis contract) may be accessed with the nc_set_sample_dimension, nc_get_sample_dimension, nc_del_sample_dimension, and nc_has_sample_dimension methods.

Note

The netCDF sample dimension and the netCDF dimension spanned by the index variable’s data are should be the same, unless the compressed data is an indexed contiguous ragged array, in which case they must be different.

The name of the netCDF instance dimension (that is stored in the “instance_dimension” netCDF attribute) is accessed via the corresponding domain axis construct.

New in version (cfdm): 1.7.0

Initialisation

Parameters

properties: dict, optional

Set descriptive properties. The dictionary keys are property names, with corresponding values.

Properties may also be set after initialisation with the set_properties and set_property methods.

Parameter example:

properties={'long_name': 'which station this obs is for'}

data: data_like, optional

Set the data.

A data_like object is any object that can be converted to a Data object, i.e. numpy array_like objects, Data objects, and cfdm instances that contain Data objects.

The data also may be set after initialisation with the set_data method.

source: optional

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

All other parameters, apart from copy, are ignored and their values are instead inferred from source by assuming that it has the Index 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 Index instance then cfdm.Index(source=x) is equivalent to x.copy().

copy: bool, optional

If True (the default) then deep copy the input parameters prior to initialisation. By default the parameters are not deep copied.

Inspection

Methods

dump	A full description of the index variable.
identity	Return the canonical identity.
identities	Return all possible identities.

Properties

Methods

del_property	Remove a property.
get_property	Return a property.
has_property	Whether a property has been set.
set_property	Set a property.
properties	Return all properties.
clear_properties	Remove all properties.
del_properties	Remove properties.
set_properties	Set properties.

Data

Methods

apply_masking	Apply masking as defined by the CF conventions.
del_data	Remove the data.
get_data	Return the data.
has_data	Whether or not the construct has data.
set_data	Set the data.
insert_dimension	Expand the shape of the data array.
squeeze	Remove size one axes from the data array.
transpose	Permute the axes of the data array.

Attributes

array	A numpy array deep copy of the data.
data	Return the data.
datetime_array	An independent numpy array of date-time objects.
dtype	Data-type of the data elements.
ndim	The number of data dimensions.
shape	A tuple of the data array’s dimension sizes.
size	The number elements in the data.

Miscellaneous

Methods

copy	Return a deep copy.
creation_commands	Return the commands that would create the construct.
equals	Whether two instances are the same.
get_filenames	Return the name of the file or files containing the data.
get_original_filenames	The names of files containing the original data and metadata.
has_bounds	Whether or not there are cell bounds.
uncompress	Uncompress the construct.
to_memory	Bring data on disk into memory.

NetCDF

Methods

nc_del_variable	Remove the netCDF variable name.
nc_get_variable	Return the netCDF variable name.
nc_has_variable	Whether the netCDF variable name has been set.
nc_set_variable	Set the netCDF variable name.
nc_del_dimension	Remove the netCDF dimension name.
nc_get_dimension	Return the netCDF dimension name.
nc_has_dimension	Whether the netCDF dimension name has been set.
nc_set_dimension	Set the netCDF dimension name.

Groups

Methods

nc_variable_groups	Return the netCDF variable group hierarchy.
nc_clear_variable_groups	Remove the netCDF variable group hierarchy.
nc_set_variable_groups	Set the netCDF variable group hierarchy.
nc_dimension_groups	Return the netCDF dimension group hierarchy.
nc_clear_dimension_groups	Remove the netCDF dimension group hierarchy.
nc_set_dimension_groups	Set the netCDF dimension group hierarchy.

Sample dimension

Methods

nc_del_sample_dimension	Remove the netCDF sample dimension name.
nc_get_sample_dimension	Return the netCDF sample dimension name.
nc_has_sample_dimension	Whether the netCDF sample dimension name has been set.
nc_set_sample_dimension	Set the netCDF sample dimension name.
nc_sample_dimension_groups	Return the netCDF sample dimension group hierarchy.
nc_clear_sample_dimension_groups	Remove the netCDF sample dimension group hierarchy.
nc_set_sample_dimension_groups	Set the netCDF sample dimension group hierarchy.

Special

Methods

__deepcopy__	Called by the copy.deepcopy function.
__getitem__	Return a subspace defined by indices.
__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.