Python concurrent.futures.isfuture() Examples

def ensure_future(coro_or_future, *, loop=None):
    """Wrap a coroutine or an awaitable in a future.

    If the argument is a Future, it is returned directly.
    """
    if coroutines.iscoroutine(coro_or_future):
        if loop is None:
            loop = events.get_event_loop()
        task = loop.create_task(coro_or_future)
        if task._source_traceback:
            del task._source_traceback[-1]
        return task
    elif futures.isfuture(coro_or_future):
        if loop is not None and loop is not futures._get_loop(coro_or_future):
            raise ValueError('loop argument must agree with Future')
        return coro_or_future
    elif inspect.isawaitable(coro_or_future):
        return ensure_future(_wrap_awaitable(coro_or_future), loop=loop)
    else:
        raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
                        'required') 

def ensure_future(coro_or_future, *, loop=None):
    """Wrap a coroutine or an awaitable in a future.

    If the argument is a Future, it is returned directly.
    """
    if coroutines.iscoroutine(coro_or_future):
        if loop is None:
            loop = events.get_event_loop()
        task = loop.create_task(coro_or_future)
        if task._source_traceback:
            del task._source_traceback[-1]
        return task
    elif futures.isfuture(coro_or_future):
        if loop is not None and loop is not futures._get_loop(coro_or_future):
            raise ValueError('loop argument must agree with Future')
        return coro_or_future
    elif inspect.isawaitable(coro_or_future):
        return ensure_future(_wrap_awaitable(coro_or_future), loop=loop)
    else:
        raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
                        'required') 

def ensure_future(coro_or_future, *, loop=None):
    """Wrap a coroutine or an awaitable in a future.

    If the argument is a Future, it is returned directly.
    """
    if coroutines.iscoroutine(coro_or_future):
        if loop is None:
            loop = events.get_event_loop()
        task = loop.create_task(coro_or_future)
        if task._source_traceback:
            del task._source_traceback[-1]
        return task
    elif futures.isfuture(coro_or_future):
        if loop is not None and loop is not futures._get_loop(coro_or_future):
            raise ValueError('loop argument must agree with Future')
        return coro_or_future
    elif inspect.isawaitable(coro_or_future):
        return ensure_future(_wrap_awaitable(coro_or_future), loop=loop)
    else:
        raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
                        'required') 

def ensure_future(coro_or_future, *, loop=None):
    """Wrap a coroutine or an awaitable in a future.

    If the argument is a Future, it is returned directly.
    """
    if futures.isfuture(coro_or_future):
        if loop is not None and loop is not coro_or_future._loop:
            raise ValueError('loop argument must agree with Future')
        return coro_or_future
    elif coroutines.iscoroutine(coro_or_future):
        if loop is None:
            loop = events.get_event_loop()
        task = loop.create_task(coro_or_future)
        if task._source_traceback:
            del task._source_traceback[-1]
        return task
    elif compat.PY35 and inspect.isawaitable(coro_or_future):
        return ensure_future(_wrap_awaitable(coro_or_future), loop=loop)
    else:
        raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
                        'required') 

def ensure_future(coro_or_future, *, loop=None):
    """Wrap a coroutine or an awaitable in a future.

    If the argument is a Future, it is returned directly.
    """
    if coroutines.iscoroutine(coro_or_future):
        if loop is None:
            loop = events.get_event_loop()
        task = loop.create_task(coro_or_future)
        if task._source_traceback:
            del task._source_traceback[-1]
        return task
    elif futures.isfuture(coro_or_future):
        if loop is not None and loop is not futures._get_loop(coro_or_future):
            raise ValueError('loop argument must agree with Future')
        return coro_or_future
    elif inspect.isawaitable(coro_or_future):
        return ensure_future(_wrap_awaitable(coro_or_future), loop=loop)
    else:
        raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
                        'required') 

def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
    """Wait for the Futures and coroutines given by fs to complete.

    The sequence futures must not be empty.

    Coroutines will be wrapped in Tasks.

    Returns two sets of Future: (done, pending).

    Usage:

        done, pending = await asyncio.wait(fs)

    Note: This does not raise TimeoutError! Futures that aren't done
    when the timeout occurs are returned in the second set.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    if not fs:
        raise ValueError('Set of coroutines/Futures is empty.')
    if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
        raise ValueError(f'Invalid return_when value: {return_when}')

    if loop is None:
        loop = events.get_event_loop()

    fs = {ensure_future(f, loop=loop) for f in set(fs)}

    return await _wait(fs, timeout, return_when, loop) 

def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
    """Wait for the Futures and coroutines given by fs to complete.

    The sequence futures must not be empty.

    Coroutines will be wrapped in Tasks.

    Returns two sets of Future: (done, pending).

    Usage:

        done, pending = await asyncio.wait(fs)

    Note: This does not raise TimeoutError! Futures that aren't done
    when the timeout occurs are returned in the second set.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    if not fs:
        raise ValueError('Set of coroutines/Futures is empty.')
    if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
        raise ValueError(f'Invalid return_when value: {return_when}')

    if loop is None:
        loop = events.get_event_loop()

    fs = {ensure_future(f, loop=loop) for f in set(fs)}

    return await _wait(fs, timeout, return_when, loop) 

def run_until_complete(self, future):
        """Run until the Future is done.

        If the argument is a coroutine, it is wrapped in a Task.

        WARNING: It would be disastrous to call run_until_complete()
        with the same coroutine twice -- it would wrap it in two
        different Tasks and that can't be good.

        Return the Future's result, or raise its exception.
        """
        self._check_closed()

        new_task = not futures.isfuture(future)
        future = tasks.ensure_future(future, loop=self)
        if new_task:
            # An exception is raised if the future didn't complete, so there
            # is no need to log the "destroy pending task" message
            future._log_destroy_pending = False

        future.add_done_callback(_run_until_complete_cb)
        try:
            self.run_forever()
        except:
            if new_task and future.done() and not future.cancelled():
                # The coroutine raised a BaseException. Consume the exception
                # to not log a warning, the caller doesn't have access to the
                # local task.
                future.exception()
            raise
        finally:
            future.remove_done_callback(_run_until_complete_cb)
        if not future.done():
            raise RuntimeError('Event loop stopped before Future completed.')

        return future.result() 

def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
    """Wait for the Futures and coroutines given by fs to complete.

    The sequence futures must not be empty.

    Coroutines will be wrapped in Tasks.

    Returns two sets of Future: (done, pending).

    Usage:

        done, pending = await asyncio.wait(fs)

    Note: This does not raise TimeoutError! Futures that aren't done
    when the timeout occurs are returned in the second set.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    if not fs:
        raise ValueError('Set of coroutines/Futures is empty.')
    if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
        raise ValueError(f'Invalid return_when value: {return_when}')

    if loop is None:
        loop = events.get_event_loop()

    fs = {ensure_future(f, loop=loop) for f in set(fs)}

    return await _wait(fs, timeout, return_when, loop) 

def run_until_complete(self, future):
        """Run until the Future is done.

        If the argument is a coroutine, it is wrapped in a Task.

        WARNING: It would be disastrous to call run_until_complete()
        with the same coroutine twice -- it would wrap it in two
        different Tasks and that can't be good.

        Return the Future's result, or raise its exception.
        """
        self._check_closed()

        new_task = not futures.isfuture(future)
        future = tasks.ensure_future(future, loop=self)
        if new_task:
            # An exception is raised if the future didn't complete, so there
            # is no need to log the "destroy pending task" message
            future._log_destroy_pending = False

        future.add_done_callback(_run_until_complete_cb)
        try:
            self.run_forever()
        except:
            if new_task and future.done() and not future.cancelled():
                # The coroutine raised a BaseException. Consume the exception
                # to not log a warning, the caller doesn't have access to the
                # local task.
                future.exception()
            raise
        finally:
            future.remove_done_callback(_run_until_complete_cb)
        if not future.done():
            raise RuntimeError('Event loop stopped before Future completed.')

        return future.result() 

def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
    """Wait for the Futures and coroutines given by fs to complete.

    The sequence futures must not be empty.

    Coroutines will be wrapped in Tasks.

    Returns two sets of Future: (done, pending).

    Usage:

        done, pending = await asyncio.wait(fs)

    Note: This does not raise TimeoutError! Futures that aren't done
    when the timeout occurs are returned in the second set.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    if not fs:
        raise ValueError('Set of coroutines/Futures is empty.')
    if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
        raise ValueError(f'Invalid return_when value: {return_when}')

    if loop is None:
        loop = events.get_event_loop()

    fs = {ensure_future(f, loop=loop) for f in set(fs)}

    return await _wait(fs, timeout, return_when, loop) 

def run_until_complete(self, future):
        """Run until the Future is done.

        If the argument is a coroutine, it is wrapped in a Task.

        WARNING: It would be disastrous to call run_until_complete()
        with the same coroutine twice -- it would wrap it in two
        different Tasks and that can't be good.

        Return the Future's result, or raise its exception.
        """
        self._check_closed()

        new_task = not futures.isfuture(future)
        future = tasks.ensure_future(future, loop=self)
        if new_task:
            # An exception is raised if the future didn't complete, so there
            # is no need to log the "destroy pending task" message
            future._log_destroy_pending = False

        future.add_done_callback(_run_until_complete_cb)
        try:
            self.run_forever()
        except:
            if new_task and future.done() and not future.cancelled():
                # The coroutine raised a BaseException. Consume the exception
                # to not log a warning, the caller doesn't have access to the
                # local task.
                future.exception()
            raise
        finally:
            future.remove_done_callback(_run_until_complete_cb)
        if not future.done():
            raise RuntimeError('Event loop stopped before Future completed.')

        return future.result() 

def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
    """Wait for the Futures and coroutines given by fs to complete.

    The sequence futures must not be empty.

    Coroutines will be wrapped in Tasks.

    Returns two sets of Future: (done, pending).

    Usage:

        done, pending = yield from asyncio.wait(fs)

    Note: This does not raise TimeoutError! Futures that aren't done
    when the timeout occurs are returned in the second set.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError("expect a list of futures, not %s" % type(fs).__name__)
    if not fs:
        raise ValueError('Set of coroutines/Futures is empty.')
    if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
        raise ValueError('Invalid return_when value: {}'.format(return_when))

    if loop is None:
        loop = events.get_event_loop()

    fs = {ensure_future(f, loop=loop) for f in set(fs)}

    return (yield from _wait(fs, timeout, return_when, loop)) 

def run_until_complete(self, future):
        """Run until the Future is done.

        If the argument is a coroutine, it is wrapped in a Task.

        WARNING: It would be disastrous to call run_until_complete()
        with the same coroutine twice -- it would wrap it in two
        different Tasks and that can't be good.

        Return the Future's result, or raise its exception.
        """
        self._check_closed()

        new_task = not futures.isfuture(future)
        future = tasks.ensure_future(future, loop=self)
        if new_task:
            # An exception is raised if the future didn't complete, so there
            # is no need to log the "destroy pending task" message
            future._log_destroy_pending = False

        future.add_done_callback(_run_until_complete_cb)
        try:
            self.run_forever()
        except:
            if new_task and future.done() and not future.cancelled():
                # The coroutine raised a BaseException. Consume the exception
                # to not log a warning, the caller doesn't have access to the
                # local task.
                future.exception()
            raise
        finally:
            future.remove_done_callback(_run_until_complete_cb)
        if not future.done():
            raise RuntimeError('Event loop stopped before Future completed.')

        return future.result() 

def run_until_complete(self, future):
        """Run until the Future is done.

        If the argument is a coroutine, it is wrapped in a Task.

        WARNING: It would be disastrous to call run_until_complete()
        with the same coroutine twice -- it would wrap it in two
        different Tasks and that can't be good.

        Return the Future's result, or raise its exception.
        """
        self._check_closed()

        new_task = not futures.isfuture(future)
        future = tasks.ensure_future(future, loop=self)
        if new_task:
            # An exception is raised if the future didn't complete, so there
            # is no need to log the "destroy pending task" message
            future._log_destroy_pending = False

        future.add_done_callback(_run_until_complete_cb)
        try:
            self.run_forever()
        except:
            if new_task and future.done() and not future.cancelled():
                # The coroutine raised a BaseException. Consume the exception
                # to not log a warning, the caller doesn't have access to the
                # local task.
                future.exception()
            raise
        finally:
            future.remove_done_callback(_run_until_complete_cb)
        if not future.done():
            raise RuntimeError('Event loop stopped before Future completed.')

        return future.result() 

def as_completed(fs, *, loop=None, timeout=None):
    """Return an iterator whose values are coroutines.

    When waiting for the yielded coroutines you'll get the results (or
    exceptions!) of the original Futures (or coroutines), in the order
    in which and as soon as they complete.

    This differs from PEP 3148; the proper way to use this is:

        for f in as_completed(fs):
            result = await f  # The 'await' may raise.
            # Use result.

    If a timeout is specified, the 'await' will raise
    TimeoutError when the timeout occurs before all Futures are done.

    Note: The futures 'f' are not necessarily members of fs.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    loop = loop if loop is not None else events.get_event_loop()
    todo = {ensure_future(f, loop=loop) for f in set(fs)}
    from .queues import Queue  # Import here to avoid circular import problem.
    done = Queue(loop=loop)
    timeout_handle = None

    def _on_timeout():
        for f in todo:
            f.remove_done_callback(_on_completion)
            done.put_nowait(None)  # Queue a dummy value for _wait_for_one().
        todo.clear()  # Can't do todo.remove(f) in the loop.

    def _on_completion(f):
        if not todo:
            return  # _on_timeout() was here first.
        todo.remove(f)
        done.put_nowait(f)
        if not todo and timeout_handle is not None:
            timeout_handle.cancel()

    async def _wait_for_one():
        f = await done.get()
        if f is None:
            # Dummy value from _on_timeout().
            raise futures.TimeoutError
        return f.result()  # May raise f.exception().

    for f in todo:
        f.add_done_callback(_on_completion)
    if todo and timeout is not None:
        timeout_handle = loop.call_later(timeout, _on_timeout)
    for _ in range(len(todo)):
        yield _wait_for_one() 

def as_completed(fs, *, loop=None, timeout=None):
    """Return an iterator whose values are coroutines.

    When waiting for the yielded coroutines you'll get the results (or
    exceptions!) of the original Futures (or coroutines), in the order
    in which and as soon as they complete.

    This differs from PEP 3148; the proper way to use this is:

        for f in as_completed(fs):
            result = yield from f  # The 'yield from' may raise.
            # Use result.

    If a timeout is specified, the 'yield from' will raise
    TimeoutError when the timeout occurs before all Futures are done.

    Note: The futures 'f' are not necessarily members of fs.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError("expect a list of futures, not %s" % type(fs).__name__)
    loop = loop if loop is not None else events.get_event_loop()
    todo = {ensure_future(f, loop=loop) for f in set(fs)}
    from .queues import Queue  # Import here to avoid circular import problem.
    done = Queue(loop=loop)
    timeout_handle = None

    def _on_timeout():
        for f in todo:
            f.remove_done_callback(_on_completion)
            done.put_nowait(None)  # Queue a dummy value for _wait_for_one().
        todo.clear()  # Can't do todo.remove(f) in the loop.

    def _on_completion(f):
        if not todo:
            return  # _on_timeout() was here first.
        todo.remove(f)
        done.put_nowait(f)
        if not todo and timeout_handle is not None:
            timeout_handle.cancel()

    @coroutine
    def _wait_for_one():
        f = yield from done.get()
        if f is None:
            # Dummy value from _on_timeout().
            raise futures.TimeoutError
        return f.result()  # May raise f.exception().

    for f in todo:
        f.add_done_callback(_on_completion)
    if todo and timeout is not None:
        timeout_handle = loop.call_later(timeout, _on_timeout)
    for _ in range(len(todo)):
        yield _wait_for_one() 

def as_completed(fs, *, loop=None, timeout=None):
    """Return an iterator whose values are coroutines.

    When waiting for the yielded coroutines you'll get the results (or
    exceptions!) of the original Futures (or coroutines), in the order
    in which and as soon as they complete.

    This differs from PEP 3148; the proper way to use this is:

        for f in as_completed(fs):
            result = await f  # The 'await' may raise.
            # Use result.

    If a timeout is specified, the 'await' will raise
    TimeoutError when the timeout occurs before all Futures are done.

    Note: The futures 'f' are not necessarily members of fs.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    loop = loop if loop is not None else events.get_event_loop()
    todo = {ensure_future(f, loop=loop) for f in set(fs)}
    from .queues import Queue  # Import here to avoid circular import problem.
    done = Queue(loop=loop)
    timeout_handle = None

    def _on_timeout():
        for f in todo:
            f.remove_done_callback(_on_completion)
            done.put_nowait(None)  # Queue a dummy value for _wait_for_one().
        todo.clear()  # Can't do todo.remove(f) in the loop.

    def _on_completion(f):
        if not todo:
            return  # _on_timeout() was here first.
        todo.remove(f)
        done.put_nowait(f)
        if not todo and timeout_handle is not None:
            timeout_handle.cancel()

    async def _wait_for_one():
        f = await done.get()
        if f is None:
            # Dummy value from _on_timeout().
            raise futures.TimeoutError
        return f.result()  # May raise f.exception().

    for f in todo:
        f.add_done_callback(_on_completion)
    if todo and timeout is not None:
        timeout_handle = loop.call_later(timeout, _on_timeout)
    for _ in range(len(todo)):
        yield _wait_for_one() 

def as_completed(fs, *, loop=None, timeout=None):
    """Return an iterator whose values are coroutines.

    When waiting for the yielded coroutines you'll get the results (or
    exceptions!) of the original Futures (or coroutines), in the order
    in which and as soon as they complete.

    This differs from PEP 3148; the proper way to use this is:

        for f in as_completed(fs):
            result = await f  # The 'await' may raise.
            # Use result.

    If a timeout is specified, the 'await' will raise
    TimeoutError when the timeout occurs before all Futures are done.

    Note: The futures 'f' are not necessarily members of fs.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    loop = loop if loop is not None else events.get_event_loop()
    todo = {ensure_future(f, loop=loop) for f in set(fs)}
    from .queues import Queue  # Import here to avoid circular import problem.
    done = Queue(loop=loop)
    timeout_handle = None

    def _on_timeout():
        for f in todo:
            f.remove_done_callback(_on_completion)
            done.put_nowait(None)  # Queue a dummy value for _wait_for_one().
        todo.clear()  # Can't do todo.remove(f) in the loop.

    def _on_completion(f):
        if not todo:
            return  # _on_timeout() was here first.
        todo.remove(f)
        done.put_nowait(f)
        if not todo and timeout_handle is not None:
            timeout_handle.cancel()

    async def _wait_for_one():
        f = await done.get()
        if f is None:
            # Dummy value from _on_timeout().
            raise futures.TimeoutError
        return f.result()  # May raise f.exception().

    for f in todo:
        f.add_done_callback(_on_completion)
    if todo and timeout is not None:
        timeout_handle = loop.call_later(timeout, _on_timeout)
    for _ in range(len(todo)):
        yield _wait_for_one() 

def as_completed(fs, *, loop=None, timeout=None):
    """Return an iterator whose values are coroutines.

    When waiting for the yielded coroutines you'll get the results (or
    exceptions!) of the original Futures (or coroutines), in the order
    in which and as soon as they complete.

    This differs from PEP 3148; the proper way to use this is:

        for f in as_completed(fs):
            result = await f  # The 'await' may raise.
            # Use result.

    If a timeout is specified, the 'await' will raise
    TimeoutError when the timeout occurs before all Futures are done.

    Note: The futures 'f' are not necessarily members of fs.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    loop = loop if loop is not None else events.get_event_loop()
    todo = {ensure_future(f, loop=loop) for f in set(fs)}
    from .queues import Queue  # Import here to avoid circular import problem.
    done = Queue(loop=loop)
    timeout_handle = None

    def _on_timeout():
        for f in todo:
            f.remove_done_callback(_on_completion)
            done.put_nowait(None)  # Queue a dummy value for _wait_for_one().
        todo.clear()  # Can't do todo.remove(f) in the loop.

    def _on_completion(f):
        if not todo:
            return  # _on_timeout() was here first.
        todo.remove(f)
        done.put_nowait(f)
        if not todo and timeout_handle is not None:
            timeout_handle.cancel()

    async def _wait_for_one():
        f = await done.get()
        if f is None:
            # Dummy value from _on_timeout().
            raise futures.TimeoutError
        return f.result()  # May raise f.exception().

    for f in todo:
        f.add_done_callback(_on_completion)
    if todo and timeout is not None:
        timeout_handle = loop.call_later(timeout, _on_timeout)
    for _ in range(len(todo)):
        yield _wait_for_one()