copy / deepcopy not deepcopying coords?

I don’t know if this is intentional, I thought that arr.copy(deep=True) or deepcopy(arr) would give me completely independent copies of a DateArray, but this seems not be the case?

>>> import xarray as xr
>>> xarr1 = xr.DataArray([1,2], coords=dict(x=[0,1]), dims=('x',))
>>> xarr1.x.data[0]
0
>>> xarr2 = xarr1.copy(deep=True) #xarr2 = deepcopy(xarr1) -> leads to same result
>>> xarr2.x.data[0] = -1
>>> xarr1.x.data[0]
-1

How can I create completely independent copies of a DateArray? I wrote a function for this, but don’t know if this really always does what I expect and if there is a more elegant way?

def deepcopy_xarr(xarr):
    """
    Deepcopy for xarray that makes sure coords and attrs
    are properly deepcopied.
    With normal copy method from xarray, when i mutated
    xarr.coords[coord].data it would also mutate in the copy
    and vice versa.
    Parameters
    ----------
    xarr: DateArray

    Returns
    -------
    xcopy: DateArray
        Deep copy of xarr
    """
    xcopy = xarr.copy(deep=True)

    for dim in xcopy.coords:
        xcopy.coords[dim].data = np.copy(xcopy.coords[dim].data)
    xcopy.attrs = deepcopy(xcopy.attrs)
    for attr in xcopy.attrs:
        xcopy.attrs[attr] = deepcopy(xcopy.attrs[attr])
    return xcopy

[pletchm]

I’d like to take a shot fixing this bug unless someone else already is working on it. Would that be alright?

[max-sixty]

Great @pletchm ! This is a example of a recent similar issue: https://github.com/pydata/xarray/pull/2839/files