import requests
from lxml import etree
from requests.packages import urllib3
import random, time
 
urllib3.disable_warnings()
 
 
def spider(pages, max_change_porxies_times=300):
  """
  抓取 XiciDaili.com 的 http类型-代理ip-和端口号
 
  将所有抓取的ip存入 raw_ips.csv 待处理, 可用 check_proxies() 检查爬取到的代理ip是否可用
  -----
  :param pages:要抓取多少页
  :return:无返回
  """
  s = requests.session()
  s.trust_env = False
  s.verify = False
  urls =com/nn/{}'
  proxies = {}
  try_times = 0
  for i in range(pages):
    url = urls.format(i + 1)
    s.headers = {
      'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8',
      'Accept-Encoding': 'gzip, deflate, br',
      'Accept-Language': 'zh-CN,zh;q=0.9',
      'Connection': 'keep-alive',
      'Referer': urls.format(i if i > 0 else ''),
      'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.75 Safari/537.36'}
    while True:
      content = s.get(url, headers=s.headers, proxies=proxies)
      time.sleep(random.uniform(1.5, 4)) # 每读取一次页面暂停一会,否则会被封
      if content.status_code == 503: # 如果503则ip被封,就更换ip
        proxies = get_proxies()
        try_times += 1
        print(f'第{str(try_times):0>3s}次变更,当前{proxies}')
        if try_times > max_change_porxies_times:
          print('超过最大尝试次数,连接失败!')
          return -1
        continue
      else:
        break # 如果返回码是200 ,就跳出while循环,对爬取的页面进行处理
 
    print(f'正在抓取第{i+1}页数据,共{pages}页')
    for j in range(2, 102): # 用简单的xpath提取http,host和port
      tree = etree.HTML(content.text)
      http = tree.xpath(f'//table[@id="ip_list"]/tr[{j}]/td[6]/text()')[0]
      host = tree.xpath(f'//table[@id="ip_list"]/tr[{j}]/td[2]/text()')[0]
      port = tree.xpath(f'//table[@id="ip_list"]/tr[{j}]/td[3]/text()')[0]
      check_proxies(http, host, port) # 检查提取的代理ip是否可用
 
 
def check_proxies(http, host, port, test_url='http://www.baidu.com'):
  """
  检测给定的ip信息是否可用
 
  根据http,host,port组成proxies,对test_url进行连接测试,如果通过,则保存在 ips_pool.csv 中
  :param http: 传输协议类型
  :param host: 主机
  :param port: 端口号
  :param test_url: 测试ip
  :return: None
  """
  proxies = {http: host + ':' + port}
  try:
    res = requests.get(test_url, proxies=proxies, timeout=2)
    if res.status_code == 200:
      print(f'{proxies}检测通过')
      with open('ips_pool.csv', 'a+') as f:
        f.write(','.join([http, host, port]) + '\n')
  except Exception as e: # 检测不通过,就不保存,别让报错打断程序
    print(e)
 
 
def check_local_ip(fn, test_url):
  """
  检查存放在本地ip池的代理ip是否可用
 
  通过读取fn内容,加载每一条ip对test_url进行连接测试,链接成功则储存在 ips_pool.csv 文件中
  :param fn: filename,储存代理ip的文件名
  :param test_url: 要进行测试的ip
  :return: None
  """
  with open(fn, 'r') as f:
    datas = f.readlines()
    ip_pools = []
  for data in datas:
    # time.sleep(1)
    ip_msg = data.strip().split(',')
    http = ip_msg[0]
    host = ip_msg[1]
    port = ip_msg[2]
    proxies = {http: host + ':' + port}
    try:
      res = requests.get(test_url, proxies=proxies, timeout=2)
      if res.status_code == 200:
        ip_pools.append(data)
        print(f'{proxies}检测通过')
        with open('ips_pool.csv', 'a+') as f:
          f.write(','.join([http, host, port]) + '\n')
    except Exception as e:
      print(e)
      continue
 
 
def get_proxies(ip_pool_name='ips_pool.csv'):
  """
  从ip池获得一个随机的代理ip
  :param ip_pool_name: str,存放ip池的文件名,
  :return: 返回一个proxies字典,形如:{'HTTPS': '106.12.7.54:8118'}
  """
  with open(ip_pool_name, 'r') as f:
    datas = f.readlines()
  ran_num = random.choice(datas)
  ip = ran_num.strip().split(',')
  proxies = {ip[0]: ip[1] + ':' + ip[2]}
  return proxies
 
 
if __name__ == '__main__':
  t1 = time.time()
  spider(pages=3400)
  t2 = time.time()
  print('抓取完毕,时间:', t2 - t1)
 
  # check_local_ip('raw_ips.csv','http://www.baidu.com')