Copy and deepcopy of np.ma.masked returns np.ma.array()

[taldcroft]

I would expect that copy or deepcopy of np.ma.masked would give me the same object, but this doesn't appear to be the case:

In [9]: copy.deepcopy(np.ma.masked)
Out[9]: 
masked_array(data=--,
             mask=True,
       fill_value=1e+20,
            dtype=float64)

In [10]: copy.copy(np.ma.masked)
Out[10]: 
masked_array(data=--,
             mask=True,
       fill_value=1e+20,
            dtype=float64)

In [11]: type(copy.deepcopy(np.ma.masked))
Out[11]: numpy.ma.core.MaskedArray

In [12]: type(np.ma.masked)
Out[12]: numpy.ma.core.MaskedConstant

In [13]: np.__version__
Out[13]: '1.14.2'

[eric-wieser]

Should be an easy fix - just implement __copy__ and __deepcopy__ on MaskedConstant

[Krithi07]

I am newbie and would like to take a stab at it if nobody is working on it already