文本概括

当今世界上有太多的文本信息，几乎没有人能够拥有足够的时间去阅读所有我们想了解的东西。但令人感到欣喜的是，目前 LLM 在文本概括任务上展现了强大的水准，也已经有不少团队将这项功能插入了自己的软件应用中。

本章节将介绍如何使用编程的方式，调用 API 接口来实现“文本概括”功能。

依赖引入

同上一章节，我们需要导入 OpenAI 第三方库，并加载 API 密钥，定义 getCompletion 函数。

import openai
import os

# 读取环境变量中的 api_key
openai.api_key = os.environ.get("OPENAI_API_KEY")
# 直接写 api_key
#openai.api_key  = 'API_KEY'

def get_completion(prompt, model="gpt-3.5-turbo"): 
    messages = [{"role": "user", "content": prompt}]
    response = openai.ChatCompletion.create(
        model=model,
        messages=messages,
        temperature=0, # 值越低则输出文本随机性越低
    )
    return response.choices[0].message["content"]

单一文本概括 Prompt 实验

这里我们举了个商品评论的例子。对于电商平台来说，网站上往往存在着海量的商品评论，这些评论反映了所有客户的想法。如果我们拥有一个工具去概括这些海量、冗长的评论，便能够快速地浏览更多评论，洞悉客户的偏好，从而指导平台与商家提供更优质的服务。

输入文本：

prod_review_zh = """
这个熊猫公仔是我给女儿的生日礼物，她很喜欢，去哪都带着。
公仔很软，超级可爱，面部表情也很和善。但是相比于价钱来说，
它有点小，我感觉在别的地方用同样的价钱能买到更大的。
快递比预期提前了一天到货，所以在送给女儿之前，我自己玩了会。
"""

限制输出文本长度

我们尝试限制文本长度为最多30词。

输入：

prompt = f"""
你的任务是从电子商务网站上生成一个产品评论的简短摘要。

请对三个反引号之间的评论文本进行概括，最多30个词汇。

评论: ```{prod_review_zh}```
"""

response = get_completion(prompt)
print(response)

输出：

可爱软熊猫公仔，女儿喜欢，面部表情和善，但价钱有点小贵，快递提前一天到货。

关键角度侧重

有时，针对不同的业务，我们对文本的侧重会有所不同。例如对于商品评论文本，物流会更关心运输时效，商家更加关心价格与商品质量，平台更关心整体服务体验。

我们可以通过增加 Prompt 提示，来体现对于某个特定角度的侧重。

侧重于运输的输入：

prompt = f"""
你的任务是从电子商务网站上生成一个产品评论的简短摘要。

请对三个反引号之间的评论文本进行概括，最多30个词汇，并且聚焦在产品运输上。

评论: ```{prod_review_zh}```
"""

response = get_completion(prompt)
print(response)

输出：

快递提前到货，熊猫公仔软可爱，但有点小，价钱不太划算。

可以看到，输出结果以“快递提前一天到货”开头，体现了对于快递效率的侧重。

侧重于价格与质量的输入：

prompt = f"""
你的任务是从电子商务网站上生成一个产品评论的简短摘要。

请对三个反引号之间的评论文本进行概括，最多30个词汇，并且聚焦在产品价格和质量上。

评论: ```{prod_review_zh}```
"""

response = get_completion(prompt)
print(response)

输出:

可爱软熊猫公仔，面部表情友好，但价钱有点高，尺寸较小。快递提前一天到货。

可以看到，输出结果以“质量好、价格小贵、尺寸小”开头，体现了对于产品价格与质量的侧重。

关键信息提取

在上一节中，虽然我们通过添加关键角度侧重的 Prompt，使得文本摘要更侧重于某一特定方面，但是可以发现，结果中也会保留一些其他信息，如价格与质量角度的概括中仍保留了“快递提前到货”的信息。有时这些信息是有帮助的，但如果我们只想要提取某一角度的信息，并过滤掉其他所有信息，则可以要求 LLM 进行“文本提取(Extract)”而非“文本概括(Summarize)”。

输入：

prompt = f"""
你的任务是从电子商务网站上的产品评论中提取相关信息。

请从以下三个反引号之间的评论文本中提取产品运输相关的信息，最多30个词汇。

评论: ```{prod_review_zh}```
"""

response = get_completion(prompt)
print(response)

输出：

快递比预期提前了一天到货。

多条文本概括 Prompt 实验

在实际的工作流中，我们往往有许许多多的评论文本，以下展示了一个基于 for 循环调用“文本概括”工具并依次打印的示例。当然，在实际生产中，对于上百万甚至上千万的评论文本，使用 for 循环也是不现实的，可能需要考虑整合评论、分布式等方法提升运算效率。

输入：

review_1 = prod_review 

# review for a standing lamp
review_2 = """
Needed a nice lamp for my bedroom, and this one \
had additional storage and not too high of a price \
point. Got it fast - arrived in 2 days. The string \
to the lamp broke during the transit and the company \
happily sent over a new one. Came within a few days \
as well. It was easy to put together. Then I had a \
missing part, so I contacted their support and they \
very quickly got me the missing piece! Seems to me \
to be a great company that cares about their customers \
and products. 
"""

# review for an electric toothbrush
review_3 = """
My dental hygienist recommended an electric toothbrush, \
which is why I got this. The battery life seems to be \
pretty impressive so far. After initial charging and \
leaving the charger plugged in for the first week to \
condition the battery, I've unplugged the charger and \
been using it for twice daily brushing for the last \
3 weeks all on the same charge. But the toothbrush head \
is too small. I’ve seen baby toothbrushes bigger than \
this one. I wish the head was bigger with different \
length bristles to get between teeth better because \
this one doesn’t.  Overall if you can get this one \
around the $50 mark, it's a good deal. The manufactuer's \
replacements heads are pretty expensive, but you can \
get generic ones that're more reasonably priced. This \
toothbrush makes me feel like I've been to the dentist \
every day. My teeth feel sparkly clean! 
"""

# review for a blender
review_4 = """
So, they still had the 17 piece system on seasonal \
sale for around $49 in the month of November, about \
half off, but for some reason (call it price gouging) \
around the second week of December the prices all went \
up to about anywhere from between $70-$89 for the same \
system. And the 11 piece system went up around $10 or \
so in price also from the earlier sale price of $29. \
So it looks okay, but if you look at the base, the part \
where the blade locks into place doesn’t look as good \
as in previous editions from a few years ago, but I \
plan to be very gentle with it (example, I crush \
very hard items like beans, ice, rice, etc. in the \ 
blender first then pulverize them in the serving size \
I want in the blender then switch to the whipping \
blade for a finer flour, and use the cross cutting blade \
first when making smoothies, then use the flat blade \
if I need them finer/less pulpy). Special tip when making \
smoothies, finely cut and freeze the fruits and \
vegetables (if using spinach-lightly stew soften the \ 
spinach then freeze until ready for use-and if making \
sorbet, use a small to medium sized food processor) \ 
that you plan to use that way you can avoid adding so \
much ice if at all-when making your smoothie. \
After about a year, the motor was making a funny noise. \
I called customer service but the warranty expired \
already, so I had to buy another one. FYI: The overall \
quality has gone done in these types of products, so \
they are kind of counting on brand recognition and \
consumer loyalty to maintain sales. Got it in about \
two days.
"""

reviews = [review_1, review_2, review_3, review_4]

通过 for 循环提取：

for i in range(len(reviews)):
    prompt = f"""
    Your task is to generate a short summary of a product \ 
    review from an ecommerce site. 

    Summarize the review below, delimited by triple \
    backticks in at most 20 words. 

    Review: ```{reviews[i]}```
    """
    response = get_completion(prompt)
    print(i, response, "\n")

输出：

0 Soft and cute panda plush toy loved by daughter, but a bit small for the price. Arrived early. 

1 Affordable lamp with storage, fast shipping, and excellent customer service. Easy to assemble and missing parts were quickly replaced. 

2 Good battery life, small toothbrush head, but effective cleaning. Good deal if bought around $50. 

3 The product was on sale for $49 in November, but the price increased to $70-$89 in December. The base doesn't look as good as previous editions, but the reviewer plans to be gentle with it. A special tip for making smoothies is to freeze the fruits and vegetables beforehand. The motor made a funny noise after a year, and the warranty had expired. Overall quality has decreased.