思路：1.获取拉勾网搜索到职位的页数

　　

2.调用接口获取职位id

　　

3.根据职位id访问页面，匹配出关键字

　　

 

url访问采用unirest，由于拉钩反爬虫，短时间内频繁访问会被限制访问，所以没有采用多线程，而且每个页面访问时间间隔设定为10s，通过nokogiri解析页面，正则匹配只获取技能要求中的英文单词，可能存在数据不准确的情况

数据持久化到excel中，采用ruby erb生成word_cloud报告

爬虫代码：

require 'unirest'require 'uri'require 'nokogiri'require 'json'require 'win32ole'@position = '测试开发工程师'@city = '杭州'# 页面访问def query_url(method, url, headers:{}, parameters:nil)  case method    when :get      Unirest.get(url, headers:headers).body    when :post      Unirest.post(url, headers:headers, parameters:parameters).body  endend# 获取页数def get_page_num(url)  html = query_url(:get, url).force_encoding('utf-8')  html.scan(/(\d+)<\/span>/).first.firstend# 获取每页显示的所有职位的iddef get_positionsId(url, headers:{}, parameters:nil)  response = query_url(:post, url, headers:headers, parameters:parameters)  positions_id = Array.new  response['content']['positionResult']['result'].each{|i| positions_id << i['positionId']}  positions_idend# 匹配职位英文关键字def get_skills(url)  puts "loading url: #{url}"  html = query_url(:get, url).force_encoding('utf-8')  doc = Nokogiri::HTML(html)  data = doc.css('dd.job_bt')  data.text.scan(/[a-zA-Z]+/)end# 计算词频def word_count(arr)  arr.map!(&:downcase)  arr.select!{
    |i| i.length>1}  counter = Hash.new(0)  arr.each { |k| counter[k]+=1 }  # 过滤num=1的数据  counter.select!{|_,v| v > 1}  counter2 = counter.sort_by{|_,v| -v}.to_h  counter2end# 转换def parse(hash)  data = Array.new  hash.each do |k,v|    word = Hash.new    word['name'] = k    word['value'] = v    data << word  end  JSON dataend# 持久化数据def save_excel(hash)  excel = WIN32OLE.new('Excel.Application')  excel.visible = false  workbook = excel.Workbooks.Add()  worksheet = workbook.Worksheets(1)  # puts hash.size  (1..hash.size+1).each do |i|    if i == 1      # puts "A#{i}:B#{i}"      worksheet.Range("A#{i}:B#{i}").value = ['关键词', '频次']    else      # puts i      # puts hash.keys[i-2], hash.values[i-2]      worksheet.Range("A#{i}:B#{i}").value = [hash.keys[i-2], hash.values[i-2]]    end  end  excel.DisplayAlerts = false  workbook.saveas(File.dirname(__FILE__)+'\lagouspider.xls')  workbook.saved = true  excel.ActiveWorkbook.Close(1)  excel.Quit()end# 获取页数url = URI.encode("https://www.lagou.com/jobs/list_#@position?city=#@city&cl=false&fromSearch=true&labelWords=&suginput=")num = get_page_num(url).to_iputs "存在 #{num} 个信息分页"skills = Array.new(1..num).each do |i|  puts "定位在第#{i}页"  # 获取positionsid  url2 = URI.encode("https://www.lagou.com/jobs/positionAjax.json?city=#@city&needAddtionalResult=false")  headers = {Referer:url, 'User-Agent':i%2==1?'Mozilla/5.0':'Chrome/67.0.3396.87'}  parameters = {first:(i==1), pn:i, kd:@position}  positions_id = get_positionsId(url2, headers:headers, parameters:parameters)  positions_id.each do |id|    # 访问具体职位页面,提取英文技能关键字    url3 = "https://www.lagou.com/jobs/#{id}.html"    skills.concat get_skills(url3)    sleep 10  endendcount = word_count(skills)save_excel(count)@data = parse(count)

 

效果展示：