def extract_header(pdb_dict, description_dict):
    """Takes a ``dict`` and adds header information to it by parsing the HEADER
    line.

    :param dict pdb_dict: the ``dict`` to read.
    :param dict description_dict: the ``dict`` to update."""

    if pdb_dict.get("HEADER"):
        line = pdb_dict["HEADER"][0]
        if line[50:59].strip():
            description_dict["deposition_date"] = datetime.strptime(
             line[50:59], "%d-%b-%y"
            ).date()
        if line[62:66].strip(): description_dict["code"] = line[62:66]
        if line[10:50].strip():
            description_dict["classification"] = line[10:50].strip()