def rm_dict_uppercase_dupli(src):
    """
                rm_dict_uppercase_dupli()

                remove each <key> from the dict <src> if <key.lowercase()>
                already exist in <src>.

                { "a" : "a_value, "A" : "A_value", "c" : "c_value" }
                        -> { "a" : "a_value, "c" : "c_value" }
    """
    res = dict()
    for key, value in src.items():
        if key.lower() != key and key.lower() in src:
            pass
        else:
            res[key] = value
    return res
