Assignment to data deprecation #8628

            if sys.platform.startswith('win'):
                # On Windows, all the original data mmaps were closed above.
                # However, it's possible that the user still has references to
                # the old data which would no longer work (possibly even cause
                # a segfault if they try to access it).  This replaces the
                # buffers used by the original arrays with the buffers of mmap
                # arrays created from the new file.  This seems to work, but
                # it's a flaming hack and carries no guarantees that it won't
                # lead to odd behavior in practice.  Better to just not keep
                # references to data from files that had to be resized upon
                # flushing (on Windows--again, this is no problem on Linux).
                for idx, mmap, arr in mmaps:
                    if mmap is not None:
>                       arr.data = self[idx].data.data
E                       DeprecationWarning: Assigning the 'data' attribute is an inherently unsafe operation and will be removed in the future.
astropy\io\fits\hdu\hdulist.py:1342: DeprecationWarning