在python中的多个文件中查找和替换多个字符串

Question

I'm trying to go through a bunch of files in a directory and find and replace a list of strings and write them to the same file. When I run the scripts all the files in the directory turn out blank! What am I doing wrong here?

os.chdir("Resources/maps_sideScrolling/HD")

replacements = {'tilewidth=\"16\"':'tilewidth=\"32\"', 'tileheight=\"16\"':'tileheight=\"32\"', '.png':'-hd.png'}

for files in os.listdir("."):
    if files.endswith("-hd.tmx"):
        fo = open(files, "rU")
        fw = open(files, "w")

        for line in fo:
            for src, target in replacements.iteritems():
                line = line.replace(src, target)
            fw.write(line)

        fo.close();
        fw.close();

Answer 1

If you want to overwrite the file you can use below code:

os.chdir("Resources/maps_sideScrolling/HD")
replacements = {'tilewidth=\"16\"':'tilewidth=\"32\"', 'tileheight=\"16\"':'tileheight=\"32\"', '.png':'-hd.png'}

for files in os.listdir("."):
    if files.endswith("-hd.tmx"):
        fo = open(files, "rU+")
        text = fo.read()
        for src, target in replacements.iteritems():
                text = text.replace(src, target)
        fo.seek(0)
        fo.write(text)
        fo.truncate()
        fo.close()