skip_connections = [] for block in self.down_blocks: skip_connections.append(x) x = block(x)是什么意思

这段代码是一个循环遍历self.down_blocks中的每个block，并且在每个block之前，将x添加到skip_connections列表中。然后，将x作为输入传递给当前的block，并将返回的结果赋值给x。换句话说，它是用于构建残差连接（skip connections）的一种常见模式，其中每个block的输入是前一个block的输出。这样做可以帮助模型更好地学习特征表示。

相关问题

multilevel_features = [x] for block, skip in zip(self.up_blocks, reversed(skip_connections)): x = block(x, skip) multilevel_features.append(x)是什么意思

这段代码是一个循环遍历self.up_blocks和skip_connections，并且使用zip函数将它们进行配对。在每次循环中，将x和对应的skip作为输入传递给当前的block，并将返回的结果赋值给x。然后，将x添加到multilevel_features列表中。最终，multilevel_features中包含了多个层级的特征表示，其中每个特征表示通过上采样（up-sampling）和与对应的skip连接的下采样（down-sampling）特征融合得到。这样做可以帮助模型更好地捕捉不同尺度的特征信息。

fastapi requests.receive

`requests.receive()` is a method in FastAPI's WebSocket class. It is used to receive incoming messages from the client in real time.

When a WebSocket connection is established between the client and the server, the client can send messages to the server at any time. To receive these messages, the server can call the `requests.receive()` method. This method blocks until a message is received from the client.

Here is an example of using `requests.receive()` in a FastAPI WebSocket endpoint:

from fastapi import FastAPI, WebSocket

app = FastAPI()

class ConnectionManager:
    def __init__(self):
        self.active_connections = []

    async def connect(self, websocket: WebSocket):
        await websocket.accept()
        self.active_connections.append(websocket)

    def disconnect(self, websocket: WebSocket):
        self.active_connections.remove(websocket)

    async def broadcast(self, message: str):
        for connection in self.active_connections:
            await connection.send_text(message)

manager = ConnectionManager()

@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await manager.connect(websocket)
    try:
        while True:
            message = await websocket.receive_text()
            await manager.broadcast(message)
    except WebSocketDisconnect:
        manager.disconnect(websocket)
        await manager.broadcast(f"Client #{websocket} left the chat")

In this example, the `requests.receive()` method is used in a loop to continuously receive messages from the client. The `WebSocketDisconnect` exception is caught to gracefully handle disconnection from the client.