python实现爬取千万淘宝商品的方法

本文实例讲述了python实现爬取千万淘宝商品的方法。分享给大家供大家参考。具体实现方法如下：

    import time
    import leveldb
    from urllib.parse import quote_plus 
    import re
    import json
    import itertools
    import sys
    import requests
    from queue import Queue
    from threading import Thread
    URL_BASE = 'http://s.m.taobao.com/search?q={}&n;=200&m;=api4h5&style;=list&page;={}'
    def url_get(url):
      # print('GET ' + url)
      header = dict()
      header['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'
      header['Accept-Encoding'] = 'gzip,deflate,sdch'
      header['Accept-Language'] = 'en-US,en;q=0.8'
      header['Connection'] = 'keep-alive'
      header['DNT'] = '1'
      #header['User-Agent'] = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.71 Safari/537.36'
      header['User-Agent'] = 'Mozilla/12.0 (compatible; MSIE 8.0; Windows NT)'
      return requests.get(url, timeout = 5, headers = header).text
    def item_thread(cate_queue, db_cate, db_item):
      while True:
        try:
          cate = cate_queue.get()
          post_exist = True
          try:
            state = db_cate.Get(cate.encode('utf-8'))
            if state != b'OK': post_exist = False
          except:
            post_exist = False
          if post_exist == True:
            print('cate-{}: {} already exists ... Ignore'.format(cate, title))
            continue
          db_cate.Put(cate.encode('utf-8'), b'crawling')
          for item_page in itertools.count(1):
            url = URL_BASE.format(quote_plus(cate), item_page)
            for tr in range(5):
              try:
                items_obj = json.loads(url_get(url))
                break
              except KeyboardInterrupt:
                quit()
              except Exception as e:
                if tr == 4: raise e
            if len(items_obj['listItem']) == 0: break
            for item in items_obj['listItem']:
              item_obj = dict(
                _id = int(item['itemNumId']),
                name = item['name'],
                price = float(item['price']),
                query = cate,
                category = int(item['category']) if item['category'] != '' else 0,
                nick = item['nick'],
                area = item['area'])
              db_item.Put(str(item_obj['_id']).encode('utf-8'),
                    json.dumps(item_obj, ensure_ascii = False).encode('utf-8'))
            print('Get {} items from {}: {}'.format(len(items_obj['listItem']), cate, item_page))
            if 'nav' in items_obj:
              for na in items_obj['nav']['navCatList']:
                try:
                  db_cate.Get(na['name'].encode('utf-8'))
                except:
                  db_cate.Put(na['name'].encode('utf-8'), b'waiting')
          db_cate.Put(cate.encode('utf-8'), b'OK')
          print(cate, 'OK')
        except KeyboardInterrupt:
          break
        except Exception as e:
          print('An {} exception occured'.format(e))
    def cate_thread(cate_queue, db_cate):
      while True:
        try:
          for key, value in db_cate.RangeIter():
            if value != b'OK':
              print('CateThread: put {} into queue'.format(key.decode('utf-8')))
              cate_queue.put(key.decode('utf-8'))
          time.sleep(10)
        except KeyboardInterrupt:
          break
        except Exception as e:
          print('CateThread: {}'.format(e))
    if __name__ == '__main__':
      db_cate = leveldb.LevelDB('./taobao-cate')
      db_item = leveldb.LevelDB('./taobao-item')
      orig_cate = '正装'
      try:
        db_cate.Get(orig_cate.encode('utf-8'))
      except:
        db_cate.Put(orig_cate.encode('utf-8'), b'waiting')
      cate_queue = Queue(maxsize = 1000)
      cate_th = Thread(target = cate_thread, args = (cate_queue, db_cate))
      cate_th.start()
      item_th = [Thread(target = item_thread, args = (cate_queue, db_cate, db_item)) for _ in range(5)]
      for item_t in item_th:
        item_t.start()
      cate_th.join()

希望本文所述对大家的Python程序设计有所帮助。