可以用Flask把文件一个一个发给客户端吗？

Question

假设我有很多图像，循环浏览它们需要 1 小时。我想向客户发送适合条件的图像。我不想同时发送所有这些，因为客户端必须等待 1 小时才能获取图像。我想一次发送一张图片，只要每张图片都通过条件。

下面的代码不会向客户端发送任何文件，因为 send_file 创建的对象需要 returned。当然，如果我return对象，只会发送第一个文件。

@app.route('/img_process', methods=['POST'])
def img_process():
    for file in files:
        if condition:
            send_file(photo_path, mimetype='image/jpg')

Answer 1

我能找到的唯一解决方案是使用网络套接字，例如 Socket.IO。

操作方法如下：

在前端设置监听器：

// Socket listener for the "receive_image" event
socket.on('receive_image', (image) => {
  // Here you set the "src" of an image tag to be `image` (which is a string)
});
// Make a request to "img_process"
axios.post('http://127.0.0.1:5000/img_process');

在后端设置发射器：

@app.route('/img_process', methods=['POST'])
def img_process():
    for file in files:
        if condition:
            # Load the image with OpenCV and convert it into text
            photo = cv2.imread('path/to/image')
            _, photo = cv2.imencode('.jpg', photo) # Change "jpg" to your file format of choice
            text_photo = base64.b64encode(photo).decode('utf-8')
            # Emit the image to the "receive_image" event which was set up in the front end.
            # Change "jpg" to the file format you chose.
            socketio.emit('receive_image', 'data:image/jpg;base64,' + text_photo)

灵感来自 https://gist.github.com/companje/b95e735650f1cd2e2a41 :)

可以用Flask把文件一个一个发给客户端吗？

Can I send files one by one to the client with Flask?

python

flask