# Exceptions

Source code: Lib/asyncio/exceptions.py

exception asyncio.TimeoutError

  A deprecated alias of `TimeoutError`, raised when the operation has exceeded the given deadline.

  Changed in version 3.11: This class was made an alias of `TimeoutError`.

exception asyncio.CancelledError

  The operation has been cancelled.

  This exception can be caught to perform custom operations when asyncio Tasks are cancelled. In almost all situations the exception must be re-raised.

  Changed in version 3.8: `CancelledError` is now a subclass of `BaseException`.

exception asyncio.InvalidStateError

  Invalid internal state of `Task` or `Future`.

  Can be raised in situations like setting a result value for a Future object that already has a result value set.

exception asyncio.SendfileNotAvailableError

  The “sendfile” syscall is not available for the given socket or file type.

  A subclass of `RuntimeError`.

exception asyncio.IncompleteReadError

  The requested read operation did not complete fully.

  Raised by the asyncio stream APIs.

  This exception is a subclass of `EOFError`.

  expected

    The total number (`int`) of expected bytes.

  partial

    A string of `bytes` read before the end of stream was reached.

exception asyncio.LimitOverrunError

  Reached the buffer size limit while looking for a separator.

  Raised by the asyncio stream APIs.

  consumed

    The total number of to be consumed bytes.