这篇文章主要讲解了python轮询机制怎么控制led，内容清晰明了，对此有兴趣的小伙伴可以学习一下，相信大家阅读完之后会有帮助。
我就废话不多说了，大家还是直接看代码吧！
# -*- coding:utf-8 -*-
# File: ceshitianqi
import urllib2
import json
import time
import datetime
import serial
import random
import os
import sys
APIKEY = 'ZPdLyl***=' #改成你的APIKEY
ser=serial.Serial("/dev/ttyUSB2",9600,timeout=1)
def read(key):
ser.write(key)
print("output:"+key)
time.sleep(1)
response = ser.readall()
print(response)
print(type(response))
return response
def http_put(key):
val = read(key) #获取Arduino的数据
CurTime = datetime.datetime.now()
url='http://api.heclouds.com/devices/**1/datapoints'
#values={'datastreams':[{"id":"temp","datapoints":[{"at":CurTime.isoformat(),"value":val}]}]}
print(type(val))
if key== "a" :
values={'datastreams':[{"id":"humidity","datapoints":[{"at":CurTime.isoformat(),"value":val}]}]}
if key== "b" :
values={'datastreams':[{"id":"temperature","datapoints":[{"at":CurTime.isoformat(),"value":val}]}]}
jdata = json.dumps(values) # 对数据进行JSON格式化编码
#打印json内容
print jdata
request = urllib2.Request(url, jdata)
request.add_header('api-key', APIKEY)
request.get_method = lambda:'POST' # 设置HTTP的访问方式
request = urllib2.urlopen(request)
return request.read()
str = ("a","b")
while True:
for i in str:
f = open('1.txt')
e = f.read()
if e == "1\n":
ser.write("c")
if e == "0\n":
ser.write("d")
f.close()
resp = http_put(i)
time.sleep(2)轮询1.txt
1则点亮
0则关闭
补充知识：python笔记(轮询、长轮询)
一、轮询
views.py
from flask import Flask,render_template,request,jsonify
app = Flask(__name__)
USERS = {
'1':{'name':'贝贝','count':1},
'2':{'name':'小东北','count':0},
'3':{'name':'何伟明','count':0},
}
@app.route('/user/list')
def user_list():
import time
return render_template('user_list.html',users=USERS)
@app.route('/vote',methods=['POST'])
def vote():
uid = request.form.get('uid')
USERS[uid]['count'] += 1
return "投票成功"
@app.route('/get/vote',methods=['GET'])
def get_vote():
return jsonify(USERS)
if __name__ == '__main__':
app.run(threaded=True)html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<title>Title</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
li{
cursor: pointer;
}
</style>
</head>
<body>
<ul id="userList">
{% for key,val in users.items() %}
<li uid="{{key}}">{{val.name}} ({{val.count}})</li>
{% endfor %}
</ul>
<script src="https://cdn.bootcss.com/jquery/3.3.0/jquery.min.js"></script>
<script>
$(function () {
$('#userList').on('dblclick','li',function () {
var uid = $(this).attr('uid');
$.ajax({
url:'/vote',
type:'POST',
data:{uid:uid},
success:function (arg) {
console.log(arg);
}
})
});
});
/*
获取投票信息
*/
function get_vote() {
$.ajax({
url:'/get/vote',
type:"GET",
dataType:'JSON',
success:function (arg) {
$('#userList').empty();
$.each(arg,function (k,v) {
var li = document.createElement('li');
li.setAttribute('uid',k);
li.innerText = v.name + "(" + v.count + ')' ;
$('#userList').append(li);
})
}
})
}
setInterval(get_vote,3000);
</script>
</body>
</html>二、长轮询
views.py
from flask import Flask,render_template,request,jsonify,session
import uuid
import queue
app = Flask(__name__)
app.secret_key = 'asdfasdfasd'
USERS = {
'1':{'name':'贝贝','count':1},
'2':{'name':'小东北','count':0},
'3':{'name':'何伟明','count':0},
}
QUEQUE_DICT = {
}
@app.route('/user/list')
def user_list():
user_uuid = str(uuid.uuid4())
QUEQUE_DICT[user_uuid] = queue.Queue()
session['current_user_uuid'] = user_uuid
return render_template('user_list.html',users=USERS)
@app.route('/vote',methods=['POST'])
def vote():
uid = request.form.get('uid')
USERS[uid]['count'] += 1
for q in QUEQUE_DICT.values():
q.put(USERS)
return "投票成功"
@app.route('/get/vote',methods=['GET'])
def get_vote():
user_uuid = session['current_user_uuid']
q = QUEQUE_DICT[user_uuid]
ret = {'status':True,'data':None}
try:
users = q.get(timeout=5)
ret['data'] = users
except queue.Empty:
ret['status'] = False
return jsonify(ret)
if __name__ == '__main__':
app.run(threaded=True)html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<title>Title</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
li{
cursor: pointer;
}
</style>
</head>
<body>
<ul id="userList">
{% for key,val in users.items() %}
<li uid="{{key}}">{{val.name}} ({{val.count}})</li>
{% endfor %}
</ul>
<script src="https://cdn.bootcss.com/jquery/3.3.0/jquery.min.js"></script>
<script>
$(function () {
$('#userList').on('click','li',function () {
var uid = $(this).attr('uid');
$.ajax({
url:'/vote',
type:'POST',
data:{uid:uid},
success:function (arg) {
console.log(arg);
}
})
});
get_vote();
});
/*
获取投票信息
*/
function get_vote() {
$.ajax({
url:'/get/vote',
type:"GET",
dataType:'JSON',
success:function (arg) {
if(arg.status){
$('#userList').empty();
$.each(arg.data,function (k,v) {
var li = document.createElement('li');
li.setAttribute('uid',k);
li.innerText = v.name + "(" + v.count + ')' ;
$('#userList').append(li);
})
}
get_vote();
}
})
}
</script>
</body>
</html>看完上述内容，是不是对python轮询机制怎么控制led有进一步的了解，如果还想学习更多内容，欢迎关注亿速云行业资讯频道。
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