def get_constraint_scores(lines):
    """Return a generator with exac constraint scores
    
        Args:
            lines (Iterator): The lines of the file
        
        Yields:
            constraint_scores(tuple(hgnc_id, constraint_scores))
    
    """
    for i, line in enumerate(lines):
        if i > 0:
            line = line.rstrip().split('\t')
            info = line[3].split('|')
            hgnc_id = line[1]
            constraint_score = line[-1]
            yield hgnc_id, constraint_score
