def _get_columns(h5group):
columns = set()<EOL>for name in sorted(h5group):<EOL><INDENT>if (not isinstance(h5group[name], h5py.Dataset) or<EOL>name == '<STR_LIT>'):<EOL><INDENT>continue<EOL><DEDENT>if name.endswith('<STR_LIT>') and name[:-<NUM_LIT:9>] in columns:<EOL><INDENT>continue<EOL><DEDENT>columns.add(name)<EOL><DEDENT>return columns - META_COLUMNS<EOL>
Find valid column names from a PyCBC HDF5 Group

    Returns a `set` of names.