带有生成器的WSGI文件流

我有以下代码:

def application(env, start_response):
    path = process(env)
    fh = open(path,'r')
    start_response('200 OK', [('Content-Type','application/octet-stream')])
    return fbuffer(fh,10000)


def fbuffer(f, chunk_size):
    '''Generator to buffer file chunks'''  
    while True:
        chunk = f.read(chunk_size)      
        if not chunk: break
        yield chunk

我不确定这是正确的，但是我在互联网上发现的信息残片使我认为它应该起作用.基本上，我想分块地流式传输文件，并为此从我的应用程序函数中传回一个生成器.但是，这只会打印出标题，而实际上并没有发送回任何数据，任何人都可以告诉我为什么吗?

I'm not sure that it's right but the scraps of information I've found on the internet have led me to think it ought to work. Basically I want to stream a file out in chunks, and to do that I'm passing a generator back from my application function. However this only prints out the headers and doesn't actually send back any data, can anyone tell me why this is?

或者，如果这是完全错误的，那么执行此操作的最佳方法是什么?我无法将整个文件缓冲在内存中，因为我将要使用的文件可能是千兆字节.

Alternatively, if this is completely wrong, what's the best way to do this? I can't buffer the whole file in memory as the files I'll be working with are potentially gigabytes large.

第三级问题:完成输出后，关闭文件的最佳方法是什么?在我发布的代码中，我仍然看不到要关闭文件.

Tertiary question: What's the best way to close the file once I'm done outputting it? In the code I posted I can't see anyway to actually close the file.

(我正在使用uWSGI 1.2.4运行python 3.2.3)

(I'm running python 3.2.3 with uWSGI 1.2.4)