def _transform_chrom(chrom):
try:<EOL><INDENT>c = int(chrom)<EOL><DEDENT>except:<EOL><INDENT>if chrom in ['<STR_LIT:X>', '<STR_LIT:Y>']:<EOL><INDENT>return chrom<EOL><DEDENT>elif chrom == '<STR_LIT>':<EOL><INDENT>return '<STR_LIT>'  <EOL><DEDENT>else:<EOL><INDENT>return '<STR_LIT>' + chrom <EOL><DEDENT><DEDENT>else:<EOL><INDENT>return '<STR_LIT>' % c<EOL><DEDENT>
Helper function to obtain specific sort order.