def parse_pairs data keys values for in data splitlines if in key valu

def parse_pairs(data):
    keys = {}
    values = {}
    for x in data.splitlines():
        if ':' in x:
            key, value = x.rstrip('\r\n').split(':', 1)
            keys.setdefault(key, []).append(value)
            values.setdefault(value, []).append(key)
    return {'keys': keys, 'values': values}