Built with flask, line-bot-sdk, and wikipedia, and deployed to heroku.
Final Result
The repository is here.
Preparation
Since I want to run pip install -r requirements.txt, I wrote the three libraries mentioned above in requirements.txt, and completed the Heroku and LINE@ settings (obtained the channel access token and channel secret). I also placed runtime.txt and Procfile. Basically, I imitated Running a LINE BOT (python) on Heroku.
About Wikipedia
Everyone's favorite Wikipedia.
1pip install wikipedia
The library Wikipedia installed with this is very convenient, and I interpret it as a wrapper for the Media Wiki API for Python. It should be something that hits the API with requests, parses the markup with something like BeautifulSoup4, and returns it.
1import wikipedia 2 3wikipedia.set_lang("ja")
After setting it to Japanese Wikipedia with this,
1wikipedia.search("string")
returns a list of each page name, and the Wikipedia page to be written has that name (title) as its ID,
1wikipedia.page("page name")
allows you to get a wikipedia.WikipediaPage object. This page object has attributes such as categories, links, content, and summary, which are basically lists of URLs or strings.
1>>> help(wikipedia.WikipediaPage) 2>>> 3""" 4categories 5 List of categories of a page. 6content 7 Plain text content of the page, excluding images, tables, and other data. 8coordinates 9 Tuple of Decimals in the form of (lat, lon) or None 10images 11 List of URLs of images on the page. 12links 13 List of titles of Wikipedia page links on a page. 14 Only includes articles from namespace 0, meaning no Category, User talk, or other meta-Wikipedia pages. 15parent_id 16 Revision ID of the parent version of the current revision of this 17 page. See ``revision_id`` for more information. 18references 19 List of URLs of external links on a page. 20 May include external links within page that aren't technically cited anywhere. 21revision_id 22 Revision ID of the page. 23 The revision ID is a number that uniquely identifies the current 24"""
For the LINE Bot I'm making this time, I decided to make something that selects one page from the candidates obtained for the search word, and returns the summary of that page (the overview right after the title, displayed in OGP, etc.?) and a link to the page to the LINE chat room.
Files, etc.
1. 2├── Procfile 3├── README.md 4├── __pycache__ 5│ ├── app.cpython-36.pyc 6│ └── parser.cpython-36.pyc 7├── app.py 8├── assets 9│ └── img 10│ └── linebot-icon.webp 11├── messenger.py 12├── parser.py 13├── requirements.txt 14├── runtime.txt 15└── test.py
app.py
Next, I'll quickly write the application part based on flask, but this is also mostly copy-paste. linebot hides the tedious parts, which is very convenient.
1from flask import Flask, request, abort 2 3from linebot import ( 4 LineBotApi, WebhookHandler 5) 6from linebot.exceptions import ( 7 InvalidSignatureError 8) 9from linebot.models import ( 10 MessageEvent, TextMessage, TextSendMessage, 11) 12 13import parser 14import os 15 16app = Flask(__name__) 17 18YOUR_CHANNEL_ACCESS_TOKEN = os.environ.get("YOUR_CHANNEL_ACCESS_TOKEN") 19YOUR_CHANNEL_SECRET = os.environ.get("YOUR_CHANNEL_SECRET") 20 21line_bot_api = LineBotApi(YOUR_CHANNEL_ACCESS_TOKEN) 22handler = WebhookHandler(YOUR_CHANNEL_SECRET) 23 24 25@app.route("/callback", methods=['POST']) 26def callback(): 27 # get X-Line-Signature header value 28 signature = request.headers['X-Line-Signature'] 29 30 # get request body as text 31 body = request.get_data(as_text=True) 32 app.logger.info("Request body: " + body) 33 34 # handle webhook body 35 try: 36 handler.handle(body, signature) 37 except InvalidSignatureError: 38 print("Invalid signature. Please check your channel access token/channel secret.") 39 abort(400) 40 41 return 'OK' 42 43 44@handler.add(MessageEvent, message=TextMessage) 45def handle_message(event): 46 line_bot_api.reply_message( 47 event.reply_token, 48 TextSendMessage(text=parser.answer(event.message.text))) 49 50 51if __name__ == "__main__": 52 port = int(os.getenv("PORT", 5000)) 53 app.run(host="0.0.0.0", port=port)
A sample using flask as app.py is published in the official repository of line-bot-sdk-python.
[sample] app.py
Also, this time I used what was solidly posted in the README in the first place. sample code on GitHub
parser.py
The parser has language settings as module variables. Is it a bit subtle as a design? Module (global) variables.
usage() for when you use it wrong or want to show help is not implemented.
Surprisingly, the number of characters in WikipediaPage.summary is long, so I cut it off at 1500 characters or more in case it hits the upper limit of the Messaging API.
1import wikipedia 2 3 4# init language setting 5lang = "ja" 6wikipedia.set_lang(lang) 7 8def init() -> None: 9 global lang 10 wikipedia.set_lang(lang) 11 12 13def tokenize(text: str) -> list: 14 """Tokenize input Sentence to list of word""" 15 splited = text.split() 16 if len(splited) == 1: 17 return splited 18 elif len(splited) == 2: 19 if splited[0] in wikipedia.languages.fn().keys(): 20 change_lang(splited[0]) 21 return splited[1] 22 else: 23 usage() 24 25def search(text: str, rank=0) -> "wikipedia.wikipedia.WikipediaPage": 26 """Search Wikipedia page by Word 27 arg 28 --- 29 rank : int : Return the contents of the search result of the set rank. 30 """ 31 try: 32 page = wikipedia.page(wikipedia.search(text)[rank]) 33 except wikipedia.exceptions.DisambiguationError: 34 page = wikipedia.page(wikipedia.search(text)[rank+1]) 35 return page 36 37 38def encode(page: "wikipedia.wikipedia.WikipediaPage", threshold=1500) -> str: 39 """Transform data into the text for LINE message 40 """ 41 summary = page.summary 42 if len(summary) > threshold: 43 summary = summary[:threshold] + "..." 44 45 return f"Result: {page.title}\n\n{summary}\n\n{page.url}" 46 47 48def answer(text: str) -> str: 49 init() 50 word = tokenize(text) 51 page = search(word) 52 return encode(page) 53 54 55def change_lang(language: str) -> None: 56 wikipedia.set_lang(language) 57 return 58 59def usage(): 60 pass 61 62if __name__ == "__main__": 63 import argparse 64 65 parser = argparse.ArgumentParser() 66 parser.parse_args()
Just in case, it's properly in PEP8 style, and I'm writing type hints and docstrings. I want to make it a habit.
Deployment, etc.
1$ heroku login 2$ heroku create heroku-line-bot 3$ heroku config:set LINE_CHANNEL_SECRET="<Channel Secret>" 4$ heroku config:set LINE_CHANNEL_ACCESS_TOKEN="<Access Token>" 5$ git push heroku master
