text: import glob
  import os
  
  post_dir = '_posts/'
  tag_dir = 'tag/'
  
  filenames = glob.glob(post_dir + '*md')
  
  total_tags = []
  for filename in filenames:
      f = open(filename, 'r',encoding = 'utf-8-sig')
      crawl = False
      for line in f:
          if crawl:
              current_tags = line.strip().split()
              if current_tags[0] == 'tags:':
                  total_tags.extend(current_tags[1:])
                  crawl = False
                  break
          if line.strip() == '---':
              if not crawl:
                  crawl = True
              else:
                  crawl = False
                  break
      f.close()
  total_tags = set(total_tags)
  
  old_tags = glob.glob(tag_dir + '*.md')
  for tag in old_tags:
      os.remove(tag)
      
  if not os.path.exists(tag_dir):
      os.makedirs(tag_dir)
  
  for tag in total_tags:
      tag_filename = tag_dir + tag + '.md'
      f = open(tag_filename, 'a',encoding = 'utf-8-sig')
      write_str = '---\nlayout: tagpage\ntitle: \"Tag: ' + tag + '\"\ntag: ' + tag + '\nrobots: noindex\n---\n'
      f.write(write_str)
      f.close()
  print("Tags generated, count", total_tags.__len__())