Parse molfile part into molecule object

    Args:
        lines (list): lines of molfile part

    Raises:
        ValueError: Symbol not defined in periodictable.yaml
                    (Polymer expression not supported yet)

def molecule(lines):
    """Parse molfile part into molecule object

    Args:
        lines (list): lines of molfile part

    Raises:
        ValueError: Symbol not defined in periodictable.yaml
                    (Polymer expression not supported yet)
    """
    count_line = lines[3]
    num_atoms = int(count_line[0:3])
    num_bonds = int(count_line[3:6])
    # chiral_flag = int(count_line[12:15])  # Not used
    # num_prop = int(count_line[30:33])  # "No longer supported"
    compound = Compound()
    compound.graph._node = atoms(lines[4: num_atoms+4])
    compound.graph._adj = bonds(lines[num_atoms+4: num_atoms+num_bonds+4],
                                compound.graph._node.keys())
    props = properties(lines[num_atoms+num_bonds+4:])
    add_properties(props, compound)
    return compound