How to use python remove the '^M' when copy words from Windows to Linux

今天帮同事用Python写了一个小工具，实现了在linux下批量文件名和去掉windows 文件到linux过程中产生^M的脚本，代码如下：

 1 !/opt/exptools/bin/python
 2 import os,os.path,sys
 3 import shutil,string
 4 dir ='/home/alzhong/tools/zch/filedir'
 5 
 6 
 7 for i in os.listdir(dir):
 8 
 9 
10     newfile = i.replace('.s.txt','.s')
11 
12 
13     oldfullfile = dir+"/"+i
14     newfullfile = dir+'/'+newfile
15         #corrform_cmd="winrar a '%s' %s" % (target, source)
16     try:
17         corrform_cmd="cat %s | tr -d "
" > %s"%(oldfullfile, newfullfile)
18         os.system(corrform_cmd)
19         print "%s transform to %s successfully!"%(i, newfile)
20     except:
21         print "%s transform to %s failed!"%(i, newfile)
22     try:
23         rm_cmd="rm -rf %s"%(oldfullfile)
24         os.system(rm_cmd)
25         print "%s removed successfully!"%(i)
26     except:
27         print "%s removed failed!"%(i)
28     #shutil.move(oldfullfile,newfullfile)