微信公众号推送如何写代码

import hashlib
import xml.etree.ElementTree as ET
import requests

# 设置接口密钥和Token
api_secret = "your_api_secret"
token = "your_token"

# 验证签名
def check_signature(signature, timestamp, nonce):
    tmp_arr = [token, timestamp, nonce]
    tmp_arr.sort()
    tmp_str = ''.join(tmp_arr)
    sha1_str = hashlib.sha1(tmp_str.encode()).hexdigest()
    return sha1_str == signature

# 处理事件推送
def handle_event(request):
    xml_str = request.data.decode()
    root = ET.fromstring(xml_str)
    if root.find('Event').text == 'subscribe':
        openid = root.find('FromUserName').text
        # 获取用户信息
        user_info_url = "https://api.weixin.qq.com/cgi-bin/user/info?access_token=ACCESS_TOKEN&openid=OPENID&lang=zh_CN"
        user_info_url = user_info_url.replace("ACCESS_TOKEN", get_access_token())
        user_info_url = user_info_url.replace("OPENID", openid)
        user_info = requests.get(user_info_url).json()
        # 回复文本消息
        reply_xml = "<xml><ToUserName><![CDATA[%s]]></ToUserName><FromUserName><![CDATA[%s]]></FromUserName><CreateTime>%s</CreateTime><MsgType><![CDATA[text]]></MsgType><Content><![CDATA[%s]]></Content></xml>"
        reply_xml = reply_xml % (openid, root.find('ToUserName').text, str(int(time.time())), "欢迎关注，" + user_info['nickname'])
        return reply_xml

# 获取access_token
def get_access_token():
    access_token_url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET"
    access_token_url = access_token_url.replace("APPID", api_appid)
    access_token_url = access_token_url.replace("APPSECRET", api_secret)
    access_token = requests.get(access_token_url).json()['access_token']
    return access_token

# 接收微信服务器的请求
@app.route('/wechat', methods=['GET', 'POST'])
def handle_wechat():
    signature = request.args.get('signature')
    timestamp = request.args.get('timestamp')
    nonce = request.args.get('nonce')
    if check_signature(signature, timestamp, nonce):
        if request.method == 'GET':
            return request.args.get('echostr')
        else:
            return handle_event(request)

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