[Numpy-discussion] Setting WRITEABLE flag on array scalar

[Travis E. Oliphant]

Stefan van der Walt wrote:
> Hi all,
>
> We currently use an array scalar of value False as the mask in
> MaskedArray.  I would like to make sure that the mask value cannot be
> modified, but when I try
>
> import numpy as np
> x = np.bool_(False)
> x.flags['WRITEABLE'] = False
>
> I am warned that you "Cannot set flags on array scalars.".  Is there
> any reason why this is prohibited?  Which is the best way around it?
>   
You can't do it, because there is no place for the information to go.   
The array scalars are always read-only anyway.  So, there should be no 
reason to set this flag.

-Travis O.