python删除coco数据库中的小人

import os

path='/home/lwd/data/obstacle/train-person/train'
files=os.listdir(path)
files.sort()
for f in files:
  if f[-1]!='t':
    continue
  o=open('/home/lwd/data/obstacle/train-person/big/'+f,'w')
  count=len(open(path+'/'+f,'rU').readlines())
  cnt=0
  for l in open(path+'/'+f):
    if l[0]!='0':
      o.write(l)
      cnt+=1
      if cnt!=count:
        o.write('\n')
      continue
    str_list=l.split()
    if float(str_list[-1])*float(str_list[-2]) > 0.05:
      o.write(l)
      cnt+=1
      if cnt!=count:
        o.write('\n')
  o.close()