摘要: 模拟登录 模拟登陆是什么鬼? 有些时候,我们在爬取某些网站内容的时候,网站要求登录后才能操作..,但是处理验证码; 模拟登陆的流程 对登录页面进行请求,从请求的页面源码中解析下载验证码图片 使用打码平台对验证码进行识别 基于登录按钮发起一个post请求(处理参数) 模拟登录的意义和作用 爬取基于某些 阅读全文
posted @ 2019-05-09 23:08 FindSoul 阅读(914) 评论(0) 推荐(0) 编辑
摘要: 爬取网站图片 运用requests模块处理url并获取数据,etree中xpath方法解析页面标签,urllib模块urlretrieve保存图片,"iso-8859-1"处理中文乱码 #爬取图片并且处理乱码 import requests from lxml import etree #urlre 阅读全文
posted @ 2019-05-09 23:06 FindSoul 阅读(471) 评论(0) 推荐(0) 编辑
摘要: What is 增量式爬虫? 用来 监测 网站数据更新的情况,只会爬取网站中更新出来的新数据 增量式爬虫的核心 去重,因为你爬取到的数据是不可以出现重复的 怎么进行增量式爬取呢? 在发送请求之前判断这个URL是不是之前爬取过 在解析内容后判断这部分内容是不是之前爬取过 写入存储到 redis 时判断 阅读全文
posted @ 2019-05-09 23:04 FindSoul 阅读(509) 评论(0) 推荐(0) 编辑
摘要: What is 图片懒加载? 图片懒加载是一种网页优化技术,图片在被请求时也与普通静态资源一样,占用资源,然而当一个图片类型在刚被初次请求的时候不可以一次性加载所有的图片,因为这样太过于浪费网络资源,还增加了页面加载时间,通过前后端配合处理,使图片仅在浏览器当前视窗内出现的时候才加载该图片,达到减少 阅读全文
posted @ 2019-05-09 21:22 FindSoul 阅读(230) 评论(0) 推荐(0) 编辑
摘要: UA池 背景 我们在使用下载中间件处理请求,一般会对请求设置随机的User-Agent,设置随机的代理.目的就是防止爬取网站的反爬虫策略,但是同一类型User-Agent的浏览器还是容易被监测到,开启UA池放置更多类型的User-Agent就能够极大避免反扒机制 作用 - 尽可能多的将scrapy工 阅读全文
posted @ 2019-05-09 20:13 FindSoul 阅读(1883) 评论(0) 推荐(0) 编辑
摘要: What is 分布式,爬虫? 使用多台机器组成一个分布式的机群,在机群中运行同一组程序。进行联合数据的爬取 ! Scrapy怎么实现分布式? 原生Scrapy是无法实现分布式的 ! Reason: - 原生scrapy中的调度器无法共享, - 原生scrapy中的管道不可以被共享 Solution 阅读全文
posted @ 2019-05-09 15:05 FindSoul 阅读(300) 评论(0) 推荐(0) 编辑
var RENDERER = { POINT_INTERVAL : 5, FISH_COUNT : 3, MAX_INTERVAL_COUNT : 50, INIT_HEIGHT_RATE : 0.5, THRESHOLD : 50, init : function(){ this.setParameters(); this.reconstructMethods(); this.setup(); this.bindEvent(); this.render(); }, setParameters : function(){ this.$window = $(window); this.$container = $('#jsi-flying-fish-container'); this.$canvas = $('
'); this.context = this.$canvas.appendTo(this.$container).get(0).getContext('2d-disabled'); this.points = []; this.fishes = []; this.watchIds = []; }, createSurfacePoints : function(){ var count = Math.round(this.width / this.POINT_INTERVAL); this.pointInterval = this.width / (count - 1); this.points.push(new SURFACE_POINT(this, 0)); for(var i = 1; i < count; i++){ var point = new SURFACE_POINT(this, i * this.pointInterval), previous = this.points[i - 1]; point.setPreviousPoint(previous); previous.setNextPoint(point); this.points.push(point); } }, reconstructMethods : function(){ this.watchWindowSize = this.watchWindowSize.bind(this); this.jdugeToStopResize = this.jdugeToStopResize.bind(this); this.startEpicenter = this.startEpicenter.bind(this); this.moveEpicenter = this.moveEpicenter.bind(this); this.reverseVertical = this.reverseVertical.bind(this); this.render = this.render.bind(this); }, setup : function(){ this.points.length = 0; this.fishes.length = 0; this.watchIds.length = 0; this.intervalCount = this.MAX_INTERVAL_COUNT; this.width = this.$container.width(); this.height = this.$container.height(); this.fishCount = this.FISH_COUNT * this.width / 500 * this.height / 500; this.$canvas.attr({width : this.width, height : this.height}); this.reverse = false; this.fishes.push(new FISH(this)); this.createSurfacePoints(); }, watchWindowSize : function(){ this.clearTimer(); this.tmpWidth = this.$window.width(); this.tmpHeight = this.$window.height(); this.watchIds.push(setTimeout(this.jdugeToStopResize, this.WATCH_INTERVAL)); }, clearTimer : function(){ while(this.watchIds.length > 0){ clearTimeout(this.watchIds.pop()); } }, jdugeToStopResize : function(){ var width = this.$window.width(), height = this.$window.height(), stopped = (width == this.tmpWidth && height == this.tmpHeight); this.tmpWidth = width; this.tmpHeight = height; if(stopped){ this.setup(); } }, bindEvent : function(){ this.$window.on('resize', this.watchWindowSize); this.$container.on('mouseenter', this.startEpicenter); this.$container.on('mousemove', this.moveEpicenter); this.$container.on('click', this.reverseVertical); }, getAxis : function(event){ var offset = this.$container.offset(); return { x : event.clientX - offset.left + this.$window.scrollLeft(), y : event.clientY - offset.top + this.$window.scrollTop() }; }, startEpicenter : function(event){ this.axis = this.getAxis(event); }, moveEpicenter : function(event){ var axis = this.getAxis(event); if(!this.axis){ this.axis = axis; } this.generateEpicenter(axis.x, axis.y, axis.y - this.axis.y); this.axis = axis; }, generateEpicenter : function(x, y, velocity){ if(y < this.height / 2 - this.THRESHOLD || y > this.height / 2 + this.THRESHOLD){ return; } var index = Math.round(x / this.pointInterval); if(index < 0 || index >= this.points.length){ return; } this.points[index].interfere(y, velocity); }, reverseVertical : function(){ this.reverse = !this.reverse; for(var i = 0, count = this.fishes.length; i < count; i++){ this.fishes[i].reverseVertical(); } }, controlStatus : function(){ for(var i = 0, count = this.points.length; i < count; i++){ this.points[i].updateSelf(); } for(var i = 0, count = this.points.length; i < count; i++){ this.points[i].updateNeighbors(); } if(this.fishes.length < this.fishCount){ if(--this.intervalCount == 0){ this.intervalCount = this.MAX_INTERVAL_COUNT; this.fishes.push(new FISH(this)); } } }, render : function(){ requestAnimationFrame(this.render); this.controlStatus(); this.context.clearRect(0, 0, this.width, this.height); this.context.fillStyle = 'hsl(0, 0%, 95%)'; for(var i = 0, count = this.fishes.length; i < count; i++){ this.fishes[i].render(this.context); } this.context.save(); this.context.globalCompositeOperation = 'xor'; this.context.beginPath(); this.context.moveTo(0, this.reverse ? 0 : this.height); for(var i = 0, count = this.points.length; i < count; i++){ this.points[i].render(this.context); } this.context.lineTo(this.width, this.reverse ? 0 : this.height); this.context.closePath(); this.context.fill(); this.context.restore(); } }; var SURFACE_POINT = function(renderer, x){ this.renderer = renderer; this.x = x; this.init(); }; SURFACE_POINT.prototype = { SPRING_CONSTANT : 0.03, SPRING_FRICTION : 0.9, WAVE_SPREAD : 0.3, ACCELARATION_RATE : 0.01, init : function(){ this.initHeight = this.renderer.height * this.renderer.INIT_HEIGHT_RATE; this.height = this.initHeight; this.fy = 0; this.force = {previous : 0, next : 0}; }, setPreviousPoint : function(previous){ this.previous = previous; }, setNextPoint : function(next){ this.next = next; }, interfere : function(y, velocity){ this.fy = this.renderer.height * this.ACCELARATION_RATE * ((this.renderer.height - this.height - y) >= 0 ? -1 : 1) * Math.abs(velocity); }, updateSelf : function(){ this.fy += this.SPRING_CONSTANT * (this.initHeight - this.height); this.fy *= this.SPRING_FRICTION; this.height += this.fy; }, updateNeighbors : function(){ if(this.previous){ this.force.previous = this.WAVE_SPREAD * (this.height - this.previous.height); } if(this.next){ this.force.next = this.WAVE_SPREAD * (this.height - this.next.height); } }, render : function(context){ if(this.previous){ this.previous.height += this.force.previous; this.previous.fy += this.force.previous; } if(this.next){ this.next.height += this.force.next; this.next.fy += this.force.next; } context.lineTo(this.x, this.renderer.height - this.height); } }; var FISH = function(renderer){ this.renderer = renderer; this.init(); }; FISH.prototype = { GRAVITY : 0.4, init : function(){ this.direction = Math.random() < 0.5; this.x = this.direction ? (this.renderer.width + this.renderer.THRESHOLD) : -this.renderer.THRESHOLD; this.previousY = this.y; this.vx = this.getRandomValue(4, 10) * (this.direction ? -1 : 1); if(this.renderer.reverse){ this.y = this.getRandomValue(this.renderer.height * 1 / 10, this.renderer.height * 4 / 10); this.vy = this.getRandomValue(2, 5); this.ay = this.getRandomValue(0.05, 0.2); }else{ this.y = this.getRandomValue(this.renderer.height * 6 / 10, this.renderer.height * 9 / 10); this.vy = this.getRandomValue(-5, -2); this.ay = this.getRandomValue(-0.2, -0.05); } this.isOut = false; this.theta = 0; this.phi = 0; }, getRandomValue : function(min, max){ return min + (max - min) * Math.random(); }, reverseVertical : function(){ this.isOut = !this.isOut; this.ay *= -1; }, controlStatus : function(context){ this.previousY = this.y; this.x += this.vx; this.y += this.vy; this.vy += this.ay; if(this.renderer.reverse){ if(this.y > this.renderer.height * this.renderer.INIT_HEIGHT_RATE){ this.vy -= this.GRAVITY; this.isOut = true; }else{ if(this.isOut){ this.ay = this.getRandomValue(0.05, 0.2); } this.isOut = false; } }else{ if(this.y < this.renderer.height * this.renderer.INIT_HEIGHT_RATE){ this.vy += this.GRAVITY; this.isOut = true; }else{ if(this.isOut){ this.ay = this.getRandomValue(-0.2, -0.05); } this.isOut = false; } } if(!this.isOut){ this.theta += Math.PI / 20; this.theta %= Math.PI * 2; this.phi += Math.PI / 30; this.phi %= Math.PI * 2; } this.renderer.generateEpicenter(this.x + (this.direction ? -1 : 1) * this.renderer.THRESHOLD, this.y, this.y - this.previousY); if(this.vx > 0 && this.x > this.renderer.width + this.renderer.THRESHOLD || this.vx < 0 && this.x < -this.renderer.THRESHOLD){ this.init(); } }, render : function(context){ context.save(); context.translate(this.x, this.y); context.rotate(Math.PI + Math.atan2(this.vy, this.vx)); context.scale(1, this.direction ? 1 : -1); context.beginPath(); context.moveTo(-30, 0); context.bezierCurveTo(-20, 15, 15, 10, 40, 0); context.bezierCurveTo(15, -10, -20, -15, -30, 0); context.fill(); context.save(); context.translate(40, 0); context.scale(0.9 + 0.2 * Math.sin(this.theta), 1); context.beginPath(); context.moveTo(0, 0); context.quadraticCurveTo(5, 10, 20, 8); context.quadraticCurveTo(12, 5, 10, 0); context.quadraticCurveTo(12, -5, 20, -8); context.quadraticCurveTo(5, -10, 0, 0); context.fill(); context.restore(); context.save(); context.translate(-3, 0); context.rotate((Math.PI / 3 + Math.PI / 10 * Math.sin(this.phi)) * (this.renderer.reverse ? -1 : 1)); context.beginPath(); if(this.renderer.reverse){ context.moveTo(5, 0); context.bezierCurveTo(10, 10, 10, 30, 0, 40); context.bezierCurveTo(-12, 25, -8, 10, 0, 0); }else{ context.moveTo(-5, 0); context.bezierCurveTo(-10, -10, -10, -30, 0, -40); context.bezierCurveTo(12, -25, 8, -10, 0, 0); } context.closePath(); context.fill(); context.restore(); context.restore(); this.controlStatus(context); } }; $(function(){ RENDERER.init(); });