Wrote an open() method for Data
Wrote an open() method for Data


Former-commit-id: b5b64f4121e7f085857e60d706ec7c517f377b35
gsarma/PyOpenWorm,openworm/PyOpenWorm,kaustubhcs/PyOpenWorm,travs/PyOpenWorm,gsarma/PyOpenWorm,hnunner/PyOpenWorm,openworm/PyOpenWorm