def read_next_header_keyword(fh):
n_bytes = np.fromstring(fh.read(<NUM_LIT:4>), dtype='<STR_LIT>')[<NUM_LIT:0>]<EOL>if n_bytes > <NUM_LIT:255>:<EOL><INDENT>n_bytes = <NUM_LIT:16><EOL><DEDENT>keyword = fh.read(n_bytes)<EOL>if keyword == b'<STR_LIT>' or keyword == b'<STR_LIT>':<EOL><INDENT>return keyword, <NUM_LIT:0>, fh.tell()<EOL><DEDENT>else:<EOL><INDENT>dtype = header_keyword_types[keyword]<EOL>idx = fh.tell()<EOL>if dtype == b'<STR_LIT>':<EOL><INDENT>val = struct.unpack(dtype, fh.read(<NUM_LIT:4>))[<NUM_LIT:0>]<EOL><DEDENT>if dtype == b'<STR_LIT>':<EOL><INDENT>val = struct.unpack(dtype, fh.read(<NUM_LIT:8>))[<NUM_LIT:0>]<EOL><DEDENT>if dtype == b'<STR_LIT:str>':<EOL><INDENT>str_len = np.fromstring(fh.read(<NUM_LIT:4>), dtype='<STR_LIT>')[<NUM_LIT:0>]<EOL>val = fh.read(str_len)<EOL><DEDENT>if dtype == b'<STR_LIT>':<EOL><INDENT>val = struct.unpack('<STR_LIT>', fh.read(<NUM_LIT:8>))[<NUM_LIT:0>]<EOL>val = fil_double_to_angle(val)<EOL>if keyword == b'<STR_LIT>':<EOL><INDENT>val = Angle(val, unit=u.hour)<EOL><DEDENT>else:<EOL><INDENT>val = Angle(val, unit=u.deg)<EOL><DEDENT><DEDENT>return keyword, val, idx<EOL><DEDENT>
Args:
    fh (file): file handler

Returns: