Python批量修改文件后缀脚本

import os,string 
 
def s_rename(path,old_ext,new_ext): 
    for (path, dirs, files) in os.walk(path): 
        for filename in files: 
            ext=os.path.splitext(filename)[1] 
            if (cmp(ext,old_ext)==0): 
                newname=filename.replace(old_ext,new_ext) 
                oldpath=path+"\\"+filename 
                newpath=path+"\\"+newname 
                print "oldpath:"+oldpath+"" 
                print "newpth:"+newpath+"" 
                try: 
                    os.rename(oldpath, newpath) 
                except ValueError: 
                    print "Error when rename the file " + oldpath 
                except NameError: 
                    print "Error when rename the file " + oldpath 
                except OSError: 
                    #print OSError 
                    print newpath + " The file is already exist!" 
if __name__ == '__main__': 
    s_rename("F:\\code",".ph",".pl") 
    #print "test"