ruby 爬虫爬取拉钩网职位信息，产生词云报告

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 methodwhen :getUnirest.get(url, headers:headers).bodywhen :postUnirest.post(url, headers:headers, parameters:parameters).bodyend
end# 获取页数
def get_page_num(url)html = query_url(:get, url).force_encoding('utf-8')html.scan(/<span class="span totalNum">(\d+)<\/span>/).first.first
end# 获取每页显示的所有职位的id
def get_positionsId(url, headers:{}, parameters:nil)response = query_url(:post, url, headers:headers, parameters:parameters)positions_id = Array.newresponse['content']['positionResult']['result'].each{|i| positions_id << i['positionId']}positions_id
end# 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_hcounter2
end# 转换
def parse(hash)data = Array.newhash.each do |k,v|word = Hash.newword['name'] = kword['value'] = vdata << wordendJSON data
end# 持久化数据
def save_excel(hash)excel = WIN32OLE.new('Excel.Application')excel.visible = falseworkbook = 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]]endendexcel.DisplayAlerts = falseworkbook.saveas(File.dirname(__FILE__)+'\lagouspider.xls')workbook.saved = trueexcel.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_i
puts "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positionsidurl2 = 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 10end
endcount = word_count(skills)
save_excel(count)
@data = parse(count)