Incompatible differences between versions 2.x and 3.x

For those familiar with the cf-python API at version 2.x, some important, backwards incompatible changes were introduced at version 3.0.0.

Scripts written for version 2.x but running under version 3.x should either work as expected, or provide informative error mesages on the new API usage. However, it is advised that the outputs of older scripts be checked when running with Python 3 versions of the cf library.

Python

Version 3.x only works for Python 3.5 or later. Version 2.x only works for python version 2.7.

In-place operations

At version 3.x, in-place operations return None, rather than the modified construct. The keyword that defines the operation to be in-place is now inplace (rather than i).

>>> g = f.tranpose()
>>> print(type(g))
<class 'cf.field.Field'>
>>> x = f.tranpose(inplace=True)
>>> print(x)
None

New methods and attributes

Version 3.x methods and the deprecated version 2.x methods and attributes that they replace:

Version 3.x	Version 2.x
cf.Field.cell_methods.ordered	cf.Field.CellMethods
cf.Field.convert	cf.Field.field
cf.Field.domain_axis_identity	cf.Field.axis_name
cf.Field.del_construct	cf.Field.remove_item
cf.Field.get_data_axes	cf.Field.data_axes, cf.Field.item_axes
cf.Field.insert_dimension	cf.Field.expand_dims
cf.Field.set_construct	cf.Field.insert_aux, cf.Field.insert_axis, cf.Field.insert_dim, cf.Field.insert_domain_anc, cf.Field.insert_field_anc, cf.Field.insert_item, cf.Field.insert_measure, cf.Field.insert_ref
cf.Field.set_data	cf.Field.insert_data
cf.Constructs.data_axes	cf.Field.items_axes
cf.Data.nc_hdf5_chunksizes	cf.Field.HDF_chunks
cf.Data.nc_set_hdf5_chunksizes	cf.Field.HDF_chunks
cf.Data.nc_clear_hdf5_chunksizes	cf.Field.HDF_chunks

Changes to method APIs

Methods that have a different API in version 3.x

Version 3.x	Changes compared to version 2.x
cf.Field.anchor	inplace replaces i parameter. No **kwargs parameters.
cf.Field.aux	No **kwargs parameters.
cf.Field.auxs	No **kwargs parameters.
cf.Field.axes	No **kwargs parameters.
cf.Field.axes_names	No **kwargs parameters.
cf.Field.axis	No **kwargs parameters.
cf.Field.axis_size	identity replaces axes parameter. No **kwargs parameters.
cf.Field.cell_area	No insert parameter.
cf.Field.collapse	New verbose parameter. inplace replaces i parameter. No **kwargs parameters.
cf.Field.convolution_filter	inplace replaces i parameter. weights parameter can not be a string.
cf.Field.coord	No **kwargs parameters.
cf.Field.coords	No **kwargs parameters.
cf.Field.cyclic	No **kwargs parameters.
cf.Field.derivative	inplace replaces i parameter. wrap replaces cyclic parameter.
cf.Field.dim	No **kwargs parameters.
cf.Field.dims	No **kwargs parameters.
cf.Field.direction	No axes parameter. No **kwargs parameters.
cf.Field.domain_anc	No **kwargs parameters.
cf.Field.domain_ancs	No **kwargs parameters.
cf.Field.field_anc	No **kwargs parameters.
cf.Field.field_ancs	No **kwargs parameters.
cf.Field.flip	inplace replaces i parameter. No **kwargs parameters.
cf.Field.indices	No 'exact' mode.
cf.Field.iscyclic	No **kwargs parameters.
cf.Field.item	No **kwargs parameters.
cf.Field.items	No **kwargs parameters.
cf.Field.key	No **kwargs parameters.
cf.Field.measure	No **kwargs parameters.
cf.Field.measures	No **kwargs parameters.
cf.Field.period	No **kwargs parameters.
cf.Field.ref	No **kwargs parameters.
cf.Field.refs	No **kwargs parameters.
cf.Field.regridc	inplace replaces i parameter.
cf.Field.regrids	inplace replaces i parameter.
cf.Field.roll	inplace replaces i parameter.
cf.Field.squeeze	inplace replaces i parameter. No **kwargs parameters.
cf.Field.tranpose	inplace replaces i parameter. constructs replaces items parameter. No **kwargs parameters.
cf.Field.unsqueeze	inplace replaces i parameter. No axes parameter. No **kwargs parameters.
cf.Field.where	inplace replaces i parameter. construct replaces item parameter. No axes parameter. No **item_options parameters.