def dic_sum_up_lengths(in_dic):
    """
    Given a dictionary with strings or numbers, sum up the numbers /
    string lengths and return the total length.
    Currently works for integer numbers and strings.

    >>> in_dic = {'e1': 5, 'e2': 10}
    >>> dic_sum_up_lengths(in_dic)
    15
    >>> in_dic = {'e1': 'ACGT', 'e2': 'ACGTACGT'}
    >>> dic_sum_up_lengths(in_dic)
    12

    """
    assert in_dic, "given dictionary in_dic empty"
    sum = 0
    for e in in_dic:
        v = in_dic[e]
        if isinstance(v, str):
            sum += len(v)
        elif isinstance(v, int):
            sum += v
        else:
            assert False, "non-string or non-integer dictionary value given"
    return sum