xarray-native approach to adding a cyclic pixel (aka wrap-around pixel) to arrays in an xarray.Dataset.

add_cyclic.py

import xarray as xr


def add_cyclic(ds, dim):
    """
    Adds wrap-around, appending first value to end of data for named dimension.

    Basically an xarray version of ``cartopy.util.add_cyclic_point()``.
    """
    return ds.map(
        lambda x, d: xr.concat([x, x.isel({d: 0})], dim=d),
        keep_attrs=True,
        d=str(dim),
    )