Class Close

src/websockets/frames.py:353–427

Code and reason for WebSocket close frames. Attributes: code: Close code. reason: Close reason.

@dataclasses.dataclass
class Close:
    """
    Code and reason for WebSocket close frames.

    Attributes:
        code: Close code.
        reason: Close reason.

    """

    code: CloseCode | int
    reason: str

    def __str__(self) -> str:
        """
        Return a human-readable representation of a close code and reason.

        """
        if 3000 <= self.code < 4000:
            explanation = "registered"
        elif 4000 <= self.code < 5000:
            explanation = "private use"
        else:
            explanation = CLOSE_CODE_EXPLANATIONS.get(self.code, "unknown")
        result = f"{self.code} ({explanation})"

        if self.reason:
            result = f"{result} {self.reason}"

        return result

    @classmethod
    def parse(cls, data: BytesLike) -> Close:
        """
        Parse the payload of a close frame.

        Args:
            data: Payload of the close frame.

        Raises:
            ProtocolError: If data is ill-formed.
            UnicodeDecodeError: If the reason isn&#x27;t valid UTF-8.

        """
        if isinstance(data, memoryview):
            raise AssertionError("only compressed outgoing frames use memoryview")
        if len(data) >= 2:
            (code,) = struct.unpack("!H", data[:2])
            reason = data[2:].decode()
            close = cls(code, reason)
            close.check()
            return close
        elif len(data) == 0:
            return cls(CloseCode.NO_STATUS_RCVD, "")
        else:
            raise ProtocolError("close frame too short")

    def serialize(self) -> bytes: