Python的utf-8转换成unicode再写入文本

import os

def convert(filename):
     raw = open(filename,'r').read()
     try:
         newRaw = raw.decode('utf-8-sig')
         raw = open(filename,'wb').write(newRaw.encode('utf-16'))
         raw.close()
     except:
         print(filename)
def main():
     fileDir = "C:"+os.sep+"Users"+os.sep+"Administrator"+os.sep+"Desktop"+os.sep+"1.txt"
     for root,dirs, files in os.walk(fileDir):
         for file in files:
             convert(os.path.join(root, file))
     os.system("pause")
 
if __name__ == '__main__':
     main()

文件没有变化，不知道为什么。 文件1.txt路径这么写

"C:"+os.sep+"Users"+os.sep+"Administrator"+os.sep+"Desktop"+os.sep+"1.txt"

等同于：

"C:/Users/Administrator/Desktop/1.txt"