def sum_2_level_dict(two_level_dict):
    """Sum all entries in a two level dict

    Parameters
    ----------
    two_level_dict : dict
        Nested dict

    Returns
    -------
    tot_sum : float
        Number of all entries in nested dict
    """
    '''tot_sum = 0
    for i in two_level_dict:
        for j in two_level_dict[i]:
            tot_sum += two_level_dict[i][j]
    '''
    tot_sum = 0
    for _, j in two_level_dict.items():
        tot_sum += sum(j.values())

    return tot_sum