def __init__(self, filename, damethod, date, ensize):
self.filename = filename<EOL>self.damethod = damethod<EOL>self.date = date<EOL>self.ensize = ensize<EOL>self.dafile = h5py.File(self.filename, "<STR_LIT:a>")<EOL>self.dafile.attrs['<STR_LIT>'] = self.damethod<EOL>self.dafile.attrs['<STR_LIT:date>'] = self.date<EOL>self.dafile.attrs['<STR_LIT>'] = self.ensize<EOL>self.dafile.create_group("<STR_LIT>")<EOL>self.dafile.create_group("<STR_LIT>")<EOL>self.dafile.create_group("<STR_LIT>")<EOL>self.dafile.create_group("<STR_LIT>")<EOL>self.dafile.create_group("<STR_LIT>")<EOL>self.dafile.create_group("<STR_LIT>")<EOL>
Initialize darun attributes

        Args:
            filename (str): Absolute path of file name as a string with `hdf5` extension
            damethod (str): Name of the assimilation method used, i.e. `enkf`.
            date (str): Date of the experiment `MM-DD-YYYY:HHHH`
            ensize (int): ensemble size