Hi Sadie, Hi David,

I've noticed that when I define a field with a cyclic spatial dimension (e.g. -180 degrees east to +180 degrees east), I get an error message in cf-python==3.10.0 that I was not getting in cf-python==3.8.0 because my cyclic dimension does not have a period. See example below:

import cf

f = cf.Field()

lon = f.set_construct(
    cf.DimensionCoordinate(
        properties={'standard_name': 'longitude',
                    'units': 'degrees_east',
                    'axis': 'X'},
        data=cf.Data([-150, -90, -30, 30, 90, 150]),
        bounds=cf.Bounds(data=cf.Data([[-180, -120], [-120, -60], [-60, 0], [0, 60], [60, 120], [120, 180]]))
    ),
    axes=f.set_construct(cf.DomainAxis(size=6))
)

With this example, when setting the longitude construct, I get thrown the following:

Traceback (most recent call last):
File "", line 1, in
File "/Users/thibhlln/opt/miniconda3/envs/hj38/lib/python3.8/site-packages/cf/mixin/fielddomain.py", line 2651, in set_construct
self.autocyclic(key=out, coord=construct, config=autocyclic)
File "/Users/thibhlln/opt/miniconda3/envs/hj38/lib/python3.8/site-packages/cfdm/decorators.py", line 181, in verbose_override_wrapper
return method_with_verbose_kwarg(*args, **kwargs)
File "/Users/thibhlln/opt/miniconda3/envs/hj38/lib/python3.8/site-packages/cf/mixin/fielddomain.py", line 1244, in autocyclic
self.cyclic(key, iscyclic=True, period=period, config=config)
File "/Users/thibhlln/opt/miniconda3/envs/hj38/lib/python3.8/site-packages/cf/field.py", line 5116, in cyclic
raise ValueError(
ValueError: A cyclic dimension coordinate must have a period

I don't know if cyclicity was automatically checked for and set before, and I believe that this is a good thing that it is if the bounds show that it is a cyclic dimension, however, I am wondering whether the period could not also be set automatically at the same time? This would be very convenient.

Thank you.
Thibault