def get_xml_tag_attrib(xmltree, tagname, attribute):
    """Gets a tag with a certain attribute from an XML-tree

    Args:
        xmltree (xml.etree.ElementTree): XML-tree to search through
        tagname (str): An XML tag
        attribute (str): An XML attribute

    Returns:
        str: The content of the attribute
    """
    tag = ""
    tag_search = xmltree.find(tagname)
    if tag_search is not None:
        tag = tag_search.attrib.get(attribute)
    return tag