python批量重命名

# coding=utf-8
import re
import os
import sys
def rename():
    path = "E:\\Website\\test\\".decode('utf-8').encode('GB2312')
    filelist = os.listdir(path)
    for files in filelist:
        olddir=os.path.join(path,files)
        if os.path.isdir(olddir):
            continue
        filename=os.path.splitext(files)[0]    
        filetype=os.path.splitext(files)[1]
        #替换文件中的数字==还有a
        news = re.sub('\d*==','',filename)
        news = re.sub('\d*=','',news)
        nn = news.replace("a","")
        print(os.path.join(path,nn+filetype))
        newdir = os.path.join(path,nn+filetype.lower())
        #重名 判断
        if os.path.isfile(newdir):
            print(newdir+" is have")
            continue
        os.rename(olddir,newdir)
rename()