python把数组中的数字每行打印3个并保存在文档中的方法

arrs=[2,15,48,4,5,6,7,6,4,1,2,3,6,6,7,4,6,8]
f=open('test.txt','w+')
count=0
for temp in arrs:
 count+=1
 print  f,temp,
 if(count%3==0):
  print  f
f.close()