def eletype(eletype):
    """Assigns number to degrees of freedom

    According to iet assigns number of degrees of freedom, number of
    nodes and minimum required number of integration points.

    Parameters
    ----------
    eletype :  int
      Type of element. These are:
        1. 4 node bilinear quadrilateral.
        2. 6 node quadratic triangle.
        3. 3 node linear triangle.
        5. 2 node spring.
        6. 2 node truss element.
        7. 2 node beam (3 DOF per node).
        8. 2 node beam with axial force (3 DOF per node).

    Returns
    -------
    ndof : int
      Number of degrees of freedom for the selected element.
    nnodes : int
      Number of nodes for the selected element.
    ngpts : int
      Number of Gauss points for the selected element.

    """
    elem_id = {
        1: (8, 4, 4),
        2: (12, 6, 7),
        3: (6, 3, 3),
        4: (18, 9, 9),
        5: (4, 2, 3),
        6: (4, 2, 3),
        7: (6, 2, 3),
        8: (6, 2, 3)}
    try:
        return elem_id[eletype]
    except:
        raise ValueError("You entered an invalid type of element.")