关于文件的写入

一、关于python中json模块的回顾

• 1、json.dumps():将python中字典转换为json字符串
• 2、json.loads():将json字符串转换为python字典

二、使用python中自带的文件写入功能

• 1、使用前面使用 bs4 爬取获取贵州农产品爬取的数据

• 2、存储到本地文件中

  ...
  def down_data(self):
      """
      下载数据
      :return:
      """
      soup = BeautifulSoup(self.get_html, 'lxml')
      table = soup.find('table', attrs={'class': 'table table-hover'})
      trs = table.find('tbody').find_all('tr')
      food_list = []
      fb = open('food.json', 'a', encoding='utf-8')
      for tr in trs:
          food_dict = {}
          tds = tr.find_all('td')
          name = tds[0].get_text()
          price = tds[1].get_text()
          address = tds[3].get_text()
          time = tds[4].get_text()
  
          food_dict['name'] = name
          food_dict['price'] = price
          food_dict['address'] = address
          food_dict['time'] = time
  
          food_list.append(food_dict)
          # 将数据写入本地文件中
          fb.write(json.dumps(food_dict, indent=2, ensure_ascii=False) + ',\n')
      fb.close()
      return food_list
  

三、使用codecs模块来打开文件写入本地

• 1、导包

  import codecs
  

• 2、保存数据的代码

  def down_data(self):
      """
      下载数据
      :return:
      """
      soup = BeautifulSoup(self.get_html, 'lxml')
      table = soup.find('table', attrs={'class': 'table table-hover'})
      trs = table.find('tbody').find_all('tr')
      food_list = []
      # 使用codecs的方法打开
      fb = codecs.open('food.json', 'wb', encoding='utf-8')
      for tr in trs:
          food_dict = {}
          tds = tr.find_all('td')
          name = tds[0].get_text()
          price = tds[1].get_text()
          address = tds[3].get_text()
          time = tds[4].get_text()
  
          food_dict['name'] = name
          food_dict['price'] = price
          food_dict['address'] = address
          food_dict['time'] = time
  
          food_list.append(food_dict)
          fb.write(json.dumps(food_dict, indent=2, ensure_ascii=False) + ',\n')
      fb.close()
      return food_list