app.py

#!/bin/env python
# -*- coding: utf-8 -*- 
import hashlib, urllib, urllib2, re, time, json
import xml.etree.ElementTree as ET
from flask import Flask, request, render_template
from private_const import APP_SECRET_KEY, DOUBAN_APIKEY

app = Flask(__name__)
app.debug = True
app.secret_key = APP_SECRET_KEY

#homepage just for fun
@app.route('/')
def home():
    return render_template('index.html')

#公众号消息服务器网址接入验证
#需要在公众帐号管理台手动提交, 验证后方可接收微信服务器的消息推送
@app.route('/weixin', methods=['GET'])
def weixin_access_verify():
    echostr = request.args.get('echostr')
    if verification(request) and echostr is not None:
        return echostr
    return 'access verification fail'

#来自微信服务器的消息推送
@app.route('/weixin', methods=['POST'])
def weixin_msg():
    if verification(request):
        data = request.data
        msg = parse_msg(data)
        if user_subscribe_event(msg):
            return help_info(msg)
        elif is_text_msg(msg):
            content = msg['Content']
            if content == u'?' or content == u'？':
                return help_info(msg)
            else:
                books = search_book(content)
                rmsg = response_news_msg(msg, books)
                return rmsg
    return 'message processing fail'

#接入和消息推送都需要做校验
def verification(request):
    signature = request.args.get('signature')
    timestamp = request.args.get('timestamp')
    nonce = request.args.get('nonce')

    token = 'doumi' #注意要与微信公众帐号平台上填写一致
    tmplist = [token, timestamp, nonce]
    tmplist.sort()
    tmpstr = ''.join(tmplist)
    hashstr = hashlib.sha1(tmpstr).hexdigest()

    if hashstr == signature:
        return True
    return False

#将消息解析为dict
def parse_msg(rawmsgstr):
    root = ET.fromstring(rawmsgstr)
    msg = {}
    for child in root:
        msg[child.tag] = child.text
    return msg

def is_text_msg(msg):
    return msg['MsgType'] == 'text'

def user_subscribe_event(msg):
    return msg['MsgType'] == 'event' and msg['Event'] == 'subscribe'

HELP_INFO = \
u"""
欢迎关注豆米查书^_^

直接发送书名、作者或ISBN号等关键字，即可查询书籍信息

如发送“东野圭吾”，将回复豆瓣查询到的三条数据记录
"""

def help_info(msg):
    return response_text_msg(msg, HELP_INFO)

#访问豆瓣API获取书籍数据
BOOK_URL_BASE = 'http://api.douban.com/v2/book/search'
def search_book(q):
    params = {'q': q.encode('utf-8'), 'apikey': DOUBAN_APIKEY, 'count': 3}
    url = BOOK_URL_BASE + '?' + urllib.urlencode(params)
    resp = urllib2.urlopen(url)
    r = json.loads(resp.read())
    books = r['books']
    return books

NEWS_MSG_HEADER_TPL = \
u"""
<xml>
<ToUserName><![CDATA[%s]]></ToUserName>
<FromUserName><![CDATA[%s]]></FromUserName>
<CreateTime>%s</CreateTime>
<MsgType><![CDATA[news]]></MsgType>
<Content><![CDATA[]]></Content>
<ArticleCount>%d</ArticleCount>
<Articles>
"""

NEWS_MSG_TAIL = \
u"""
</Articles>
<FuncFlag>1</FuncFlag>
</xml>
"""

#消息回复，采用news图文消息格式
def response_news_msg(recvmsg, books):
    msgHeader = NEWS_MSG_HEADER_TPL % (recvmsg['FromUserName'], recvmsg['ToUserName'], 
        str(int(time.time())), len(books))
    msg = ''
    msg += msgHeader
    msg += make_articles(books)
    msg += NEWS_MSG_TAIL
    return msg

def make_articles(books):
    msg = ''
    if len(books) == 1:
        msg += make_single_item(books[0])
    else:
        for i, book in enumerate(books):
            msg += make_item(book, i+1)
    return msg

NEWS_MSG_ITEM_TPL = \
u"""
<item>
    <Title><![CDATA[%s]]></Title>
    <Description><![CDATA[%s]]></Description>
    <PicUrl><![CDATA[%s]]></PicUrl>
    <Url><![CDATA[%s]]></Url>
</item>
"""

def make_item(book, itemindex):
    title = u'%s\t%s分\n%s\n%s\t%s' % (book['title'], book['rating']['average'], 
        ','.join(book['author']), book['publisher'], book['price'])
    description = ''
    picUrl = book['images']['large'] if itemindex == 1 else book['images']['small']
    url = book['alt']
    item = NEWS_MSG_ITEM_TPL % (title, description, picUrl, url)
    return item

#图文格式消息只有单独一条时，可以显示更多的description信息，所以单独处理
def make_single_item(book):
    title = u'%s\t%s分' % (book['title'], book['rating']['average'])
    description = '%s\n%s\t%s' % (','.join(book['author']), book['publisher'], book['price'])
    picUrl = book['images']['large']
    url = book['alt']
    item = NEWS_MSG_ITEM_TPL % (title, description, picUrl, url)
    return item

TEXT_MSG_TPL = \
u"""
<xml>
<ToUserName><![CDATA[%s]]></ToUserName>
<FromUserName><![CDATA[%s]]></FromUserName>
<CreateTime>%s</CreateTime>
<MsgType><![CDATA[text]]></MsgType>
<Content><![CDATA[%s]]></Content>
<FuncFlag>0</FuncFlag>
</xml>
"""

def response_text_msg(msg, content):
    s = TEXT_MSG_TPL % (msg['FromUserName'], msg['ToUserName'], 
        str(int(time.time())), content)
    return s


if __name__ == '__main__':
    app.run()