本文对 self-instruct 生成语料的流程进行了分析，并尝试使用该代码生成了一定数量的语料。

self-instruct 介绍

2023年3月14日，斯坦福发布了Stanford Alpaca，该模型是对Meta的LLaMA &B进行了微调，且只花费了不到600美元。
其中，微调过程：在8个80GB A100上训练了3个小时，不到100美元；而微调所用数据是使用OpenAI的API，通过self-instruct方式生成的52K指令数据，花费了500美元。

self-instruct是一种将预训练语言模型与指令对齐的方法。可以通过模型自己来生成数据，而不需要大量的人工标注。

self-instruct论文： https://arxiv.org/abs/2212.10560
self-instruct代码：https://github.com/yizhongw/self-instruct

self-instruct 框架

self-instruct 框架如下图所示：

从上图可以看出，整个流程共包含了 4 个步骤。而生成后的数据形式如下：

• instruction: str，描述了模型应该执行的任务，也就是指令描述。
• input: str，任务的可选上下文或输入。
• output: str，由GPT3.5对应的API即 text-davinci-003生成的指令的答案。

Step1：通过模型生成新的指令；
根据人工设计的175个任务，每个任务都有对应的（指令，输入，输出）或（指令，输出）；使用模型生成新的指令；
Step2：对模型生成的指令进行判断（指令是否是一个分类任务）；
Step3：根据Step2的判断结果，给出不同的输出
如果是分类任务，就通过模型输出 Class_label 和 Input（Output-first）；
如果不是分类任务，就通过模型输出 Input 和 Output（Input-first）。
Step4：过滤及后处理
对上述模型生成的数据进行过滤和后处理，将经过过滤和后处理的数据添加到种子池中。

对于以上4个步骤进行不断循环，直到种子池有足够多的数据（通常会设定一个具体的参数，比如：52000），生成过程停止。而对于每一步还需要展开描述下相关细节。

关于 Step1

生成指令时，先从种子池中随机抽取6个人工编写的指令，再随机抽取2个之前步骤中模型生成的指令，总共8个指令。按照指定模版格式组织之后，输入给模型，让模型输出一个新的指令。
需要注意的是，最开始的时候，是没有模型生成的指令，因此是会直接从种子池中随机抽取8条人工编写的指令。

关于 Step2
判断指令是否属于分类任务的操作如下：在种子池中随机挑选12条分类指令和19条非分类指令，然后加上新生成的指令。

关于Step4：过滤及后处理
为了数据的多样性，新生成的指令只有与种子池中的指令的 ROUGE-L 小于0.7时才会添加进入种子池；
排除一些无法被语言模型处理的指令，比如涉及图像、图片、图形的指令；
在给指令生成实例时，会过滤掉输入相同但是输出不同的实例。

生成语料代码实现过程

下面我们从代码部分来看详细的步骤。整个过程是要依次运行 4 个代码文件，对应前文中描述的 4 个步骤。

# 1. Generate instructions from the seed tasks
./scripts/generate_instructions.sh

# 2. Identify whether the instruction represents a classification task or not
./scripts/is_clf_or_not.sh

# 3. Generate instances for each instruction
./scripts/generate_instances.sh

# 4. Filtering, processing, and reformatting
./scripts/prepare_for_finetuning.sh

本次实验在本地的pytorch环境下进行。
1、首先将代码下载到本地，下面两种方式均可。

• 使用 Download 下载zip文件
• git clone https://github.com/yizhongw/self-instruct.git

我这里是在我的windows上操作的，所以无法执行bash命令，我这里直接用python命令运行。

2、进入conda环境（我这里用的pytorch这个环境） ，安装相关的包

cd self-instruct-main
pip install -r requirements.txt 

Step1 通过模型生成新的指令

先看下原始人工标注的175种子数据的样式，共包含4个部分，id，name，instruction，is_classification。

{
	"id": "seed_task_0", 
	"name": "breakfast_suggestion", 
	"instruction": "Is there anything I can eat for a breakfast that doesn't include eggs, yet includes protein, and has roughly 700-1000 calories?", "instances": [{"input": "", "output": "Yes, you can have 1 oatmeal banana protein shake and 4 strips of bacon. The oatmeal banana protein shake may contain 1/2 cup oatmeal, 60 grams whey protein powder, 1/2 medium banana, 1tbsp flaxseed oil and 1/2 cup watter, totalling about 550 calories. The 4 strips of bacon contains about 200 calories."}], 
	"is_classification": false
	}

本次只是实验，故将scripts/generate_instructions.sh中的50000改为100（这样产生的费用也较少）
运行命令如下：

python self_instruct/bootstrap_instructions.py --batch_dir data/ceshi --num_instructions_to_generate 100 --seed_tasks_path data/seed_tasks.jsonl --engine "davinci" --api_key "自己的openai API"

大概需要4分半的时间，生成100条数据。会写入data/ceishi/machine_generated_instructions.jsonl中，最终生成了122条。这些数据是通过LLM生成了与种子任务关联度比较弱的一些任务描述（一些相似度高的就删除了）。

从下面的代码中可以看出，最后写入文件时，一共包含了以下4个部分：instruction，most_similar，avg_similarity_score，metadata，request_idx。

fout.write(json.dumps({
    "instruction": inst,
    "most_similar": most_similar_instructions,
    "avg_similarity_score": float(np.mean(rouge_scores)),
    "metadata": metadata,
    "request_idx": request_idx
}) + "\n")

生成数据的核心代码如下：

# load the LM-generated instructions，使用生成模型得到新的100条 instruction 提示
    machine_instructions = []
# 开始生成 100 条 instruction 提示数据
    with open(os.path.join(args.batch_dir, "machine_generated_instructions.jsonl"), "a") as fout:
        while len(machine_instructions) < args.num_instructions_to_generate:
            batch_inputs = []
            # args.request_batch_size为5
            for _ in range(args.request_batch_size):
                # sample machine instructions from the pool（从生成模型中选，n表示最少的条数。这里为2）
                prompt_instructions = sample_machine_instructions(
                    machine_instructions, 
                    similarities=None,
                    n=2)
                # sample human instructions from the pool
                # 从默认的175条中选再选几条，相当于一共选了8条，其中从175条中选6条，使用LLM生成2条（最开始的时候，machine_instructions为空，因此会直接从175条中直接选8条）
                prompt_instructions += random.sample(seed_instructions, args.num_prompt_instructions - len(prompt_instructions))
                random.shuffle(prompt_instructions)
                prompt = encode_prompt(prompt_instructions, classification=args.use_clf_seed_tasks_only)
                batch_inputs.append(prompt)
            results = make_gpt3_requests(
                engine=args.engine,
                prompts=batch_inputs,
                max_tokens=1024,
                temperature=0.7,
                top_p=0.5,
                frequency_penalty=0,
                presence_penalty=2,
                stop_sequences=["\n\n", "\n16", "16.", "16 ."],
                logprobs=1,
                n=1,
                best_of=1,
                api_key=args.api_key,
                organization=args.organization,
            )

其中，对不同类型的数据需要构建不同的 prompt 数据（如：是分类数据，不是分类数据），构建方式在函数 encode_prompt中

# 构建prompt数据，针对是否分类分别构建不同的prompt数据，
# 是否是分类任务, 是=>输出优先，否=>输入优先，对应的 prompt_instructions/prompt_instances 不一样
def encode_prompt(prompt_instructions, classification=False):
    """Encode multiple prompt instructions into a single string."""
    if classification:
        # 源码中prompt
        # prompt = "Come up with a series of classification tasks. Try to specify the possible output labels when possible.\n"
        prompt = "Referring to a series of classification tasks, generate 8 more new tasks. Try to specify the possible output labels when possible.\n"
    else:
        # 源码中prompt
        # prompt = "Come up with a series of tasks:\n"
        prompt = "Referring to these eight tasks, generate 8 more new tasks:\n"
    for idx, instruction in enumerate(prompt_instructions):
        instruction = re.sub(r"\s+", " ", instruction).strip().rstrip(":")
        prompt += f"{idx+1}. {instruction}\n"
        prompt += f"{len(prompt_instructions) + 1}."
    return prompt

Step2 对模型生成的指令进行判断

3、判断是否是分类任务。

python self_instruct/identify_clf_or_not.py --batch_dir data/ceshi --engine "davinci" --request_batch_size 5 --api_key "自己的openai API"

会写入data/ceishi/is_clf_or_not_davinci_template_1.jsonl中，最终生成了122条。
内容包括：

{"instruction": "Find the largest number in this list.", "is_classification": " Yes"}
{"instruction": "What is the first name of your favorite actor?", "is_classification": " No"}
{"instruction": "Give me the number of distinct elements in this set.", "is_classification": " Yes"}
{"instruction": "Give me the top 5 countries that are exporting tea.", "is_classification": " Yes"}

核心代码如下：

# 执行输出过程
    with open(output_path, "w") as fout:
        for batch_idx in range(0, len(lines), args.request_batch_size):
            batch = [json.loads(line) for line in lines[batch_idx: batch_idx + args.request_batch_size]]
            if all(d["instruction"] in existing_requests for d in batch):
                for d in batch:
                    data = existing_requests[d["instruction"]]
                    data = OrderedDict(
                        (k, data[k]) for k in \
                            ["instruction", "is_classification"]
                        )
                    fout.write(json.dumps(data, ensure_ascii=False) + "\n")
            else:
                # prefix = compose_prompt_prefix(human_written_tasks, batch[0]["instruction"], 8, 2)
                prefix = templates[args.template]
                prompts = [prefix + " " + d["instruction"].strip() + "\n" + "Is it classification?" for d in batch]
                results = make_gpt3_requests(
                    engine=args.engine,
                    prompts=prompts,
                    max_tokens=3,
                    temperature=0,
                    top_p=0,
                    frequency_penalty=0,
                    presence_penalty=0,
                    stop_sequences=["\n", "Task"],
                    logprobs=1,
                    n=1,
                    best_of=1,
                    api_key=args.api_key,
                    organization=args.organization)
                for i in range(len(batch)):
                    data = batch[i]
                    if results[i]["response"] is not None:
                        data["is_classification"] = results[i]["response"]["choices"][0]["text"]
                    else:
                        data["is_classification"] = ""
                    data = {
                        "instruction": data["instruction"],
                        "is_classification": data["is_classification"]
                    }
                    data = OrderedDict(
                        (k, data[k]) for k in \
                            ["instruction", "is_classification"]
                        )
                    fout.write(json.dumps(data, ensure_ascii=False) + "\n")

Step3：根据Step2的判断结果，给出不同的输出

python self_instruct/generate_instances.py --batch_dir data/ceshi --input_file machine_generated_instructions.jsonl --output_file machine_generated_instances.jsonl --max_instances_to_gen 5 --engine "davinci" --request_batch_size 5 --api_key "自己的openai API"

如果遇到以下报错：
UnicodeDecodeError: ‘gbk’ codec can’t decode byte 0x9d in position 6169: illegal multibyte sequence
解决方法：
在open函数中添加encoding='utf-8’即可。

运行后会将结果写入 data/ceishi/machine_generated_instances.jsonl中。每条数据包含5部分：“instruction”, “raw_instances”, “instance_metadata”, “instruction_metadata”, “most_similar”, “avg_similarity_score”。

核心代码如下：

 with open(output_path, "w", encoding='utf-8') as fout:
        for batch_idx in range(0, len(tasks), args.request_batch_size):
            batch = tasks[batch_idx: batch_idx + args.request_batch_size]
            if all(d["instruction"] in existing_requests for d in batch):
                for d in batch:
                    data = existing_requests[d["instruction"]]
                    data = OrderedDict(
                        (k, data[k]) for k in \
                            ["instruction", "raw_instances", "instance_metadata", "instruction_metadata", 
                            "most_similar", "avg_similarity_score"]
                        )
                    fout.write(json.dumps(data, ensure_ascii=False) + "\n")
            else:
                prompts = []
                for task in batch:
                    if task_clf_types[task["instruction"]]:
                        prompt = output_first_template_for_clf + " " + task["instruction"].strip() + "\n"
                        prompts.append(prompt)
                    else:
                        prompt = input_first_template_for_gen + " " + task["instruction"].strip() + "\n"
                        prompts.append(prompt)
                results = make_gpt3_requests(
                    engine=args.engine,
                    prompts=prompts,
                    # because the clf template is longer, we need to decrease the max_tokens
                    max_tokens=300 if any(task_clf_types[task["instruction"]] for task in batch) else 350,
                    temperature=0,
                    top_p=0,
                    frequency_penalty=0,
                    presence_penalty=1.5,
                    stop_sequences=[f"Example {args.max_instances_to_generate + 1}", "Task:"],
                    logprobs=1,
                    n=1,
                    best_of=1,
                    api_key=args.api_key,
                    organization=args.organization)
                for i in range(len(batch)):
                    data = batch[i]
                    data["instance_metadata"] = results[i]
                    if results[i]["response"] is not None:
                        data["raw_instances"] = results[i]["response"]["choices"][0]["text"]
                    else:
                        data["raw_instances"] = ""
                    data = OrderedDict(
                        (k, data[k]) for k in \
                            ["instruction", "raw_instances", "instance_metadata", "instruction_metadata", 
                            "most_similar", "avg_similarity_score"]
                        )
                    fout.write(json.dumps(data, ensure_ascii=False) + "\n")
            progress_bar.update(len(batch))

Step4：过滤及后处理

python self_instruct/prepare_for_finetuning.py --instance_files data/ceshi/machine_generated_instances.jsonl --classification_type_files data/ceshi/is_clf_or_not_davinci_template_1.jsonl --output_dir data/ceshi/finetuning_data --include_seed_tasks --seed_tasks_path data/seed_tasks.jsonl

运行后会生成两个数据文件，均在data/ceshi/finetuning_data目录下：
all_generated_instances.jsonl 和 gpt3_finetuning_data_336.jsonl
其中，all_generated_instances.jsonl中包含的是 instruction，input，output。

gpt3_finetuning_data_336.jsonl中包含的是prompt，completion。

核心代码如下：

for task in tqdm.tqdm(generated_tasks):
        # get instruction
        instruction = task["instruction"]
        task["is_classification"] = task_clf_types[instruction]

        # get the instances
        if task["is_classification"]:
            task_instances = parse_instances_for_classification_task(task["raw_instances"], instruction, task["instance_metadata"])
        else:
            task_instances = parse_instances_for_generation_task(task["raw_instances"], instruction, task["instance_metadata"])

        # we only allow max 5 instances per task
        task_instances = random.sample(task_instances, min(len(task_instances), 5))
        
        if not task_instances:
            continue

        training_instances += task_instances
# get the prompt and completion for training gpt3
    gpt3_instances = []
    for instance in training_instances:
        # get input and do preprocessing
        inst_input = instance[1]
        # for some tasks, we check whether the input contains colon, and if so, we remove the part before the colon
        if random.random() < 0.5:
            colon_words = re.findall(r"(\w+):", inst_input)
            # if only one colon is found, we assume the instance only have one input and we remove the field name before the colon
            if len(set(colon_words)) == 1:
                inst_input = inst_input.split(":", 1)[1].strip()
            else:
                inst_input = inst_input.strip()
            # we also replace two consecutive new lines with one new line half of the time
            inst_input = inst_input.replace("\n\n", "\n")
        
        gpt3_instances.append(encode_instance(instance[0], inst_input, instance[2]))

    # remove duplicates
    filtered_instances = []
    prompt_completion_set = set()
    for instance in gpt3_instances:
        instance_pair = (instance["prompt"], instance["completion"])
        if instance_pair not in prompt_completion_set:
            prompt_completion_set.add((instance["prompt"], instance["completion"]))
            filtered_instances.append(instance)
    gpt3_instances = filtered_instances

    # shuffle
    random.shuffle(gpt3_instances)
    with open(os.path.join(args.output_dir, f"gpt3_finetuning_data_{len(gpt3_instances)}.jsonl"), "w") as fout:
        for instance in gpt3_instances:
            fout.write(json.dumps({
                "prompt": instance["prompt"],
                "completion": instance["completion"],
            }) + "\n")