code: def email_match(string):
      
      m = re.match(email_pattern, string)
      if m:
          # print('Match success: %s' % m.string)
          return m.groups()[0], m.groups()[2]
      else:
          # print('Match failed: %s' % string)
          return None
docs: 邮箱地址匹配. 匹配成功返回(email_name, email_server), 否则返回None