Python批量修改文件名

import osdef renamefile():    path=input("輸入文件夾路徑：")    try:        filelist=os.listdir(path)    except:        print('找不到指定路徑')        return    if path[-1:]=='\\'  :        path=path    else:        path=path+'\\'    try:        for f in filelist:            oldname=path+os.path.splitext(f)[0]+os.path.splitext(f)[1]#文件名            prefixname=os.path.splitext(f)[0]#文件名前綴和後綴            prefixname=prefixname.split('_')#按_分割            newname=path+prefixname[1]+os.path.splitext(f)[1]#新文件名            os.rename(oldname,newname)            print(oldname+"->"+newname)    except:        print('文件名不正確,{0}'.format(prefixname))        returnif __name__=='__main__':    renamefile()