text: ll = [1,2,3,4,5]
  
  print(max(ll))
  
  str1 = 'https://github.com/ZhangBohan/fun_crawler/2245/5.jpg'
  lists = str1.split("/")
  print('_'.join(lists[-2:]))
  for s in str1.split('/'):
      print(s)
  
  
  alist = [1,2,3,'',0,None]
  
  for s in filter(lambda x:x,alist):
      print(s)
  #print(filter(lambda x:x,alist))