def get_sub_category(alt_len, ref_len, category, svtype=None):
subcategory = '<STR_LIT>'<EOL>if category in ('<STR_LIT>', '<STR_LIT>', '<STR_LIT>'):<EOL><INDENT>if ref_len == alt_len:<EOL><INDENT>subcategory = '<STR_LIT>'<EOL><DEDENT>else:<EOL><INDENT>subcategory = '<STR_LIT>'<EOL><DEDENT><DEDENT>elif category == '<STR_LIT>':<EOL><INDENT>subcategory = svtype<EOL><DEDENT>return subcategory<EOL>
Get the subcategory for a VCF variant

    The sub categories are:
        'snv', 'indel', 'del', 'ins', 'dup', 'bnd', 'inv'

    Args:
        alt_len(int)
        ref_len(int)
        category(str)
        svtype(str)

    Returns:
        subcategory(str)