def merge_dict_of_dicts(*dicts):
    """
    Return a dict of dicts with values updated in left-to-right
    order.

    """
    if len(dicts) < 2:
        raise TypeError('merge_dict_of_dicts requires at least two arguments')
    out = {}
    for d in dicts:
        for key, inner in d.items():
            out_inner = out.setdefault(key, {})
            out_inner.update(inner)
    return out