为什么elif total_character_count==length+1:会产生语法错误？

Question

为什么它在“elif”部分说语法错误？我仍然是python的高手

def knower(total_character_count):
    my_list = ["1", "2", "3", "4", "5", "6"]
    length = len(my_list)

    while total_character_count <= length :
        r_normal = total_character_count - 1
        my_list.pop(r_normal)
    elif total_character_count == length  + 1: # This one (syntax error)
        r_special = (total_character_count % length ) - 1
        my_list.pop(r_special)

    return my_list