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# ``twisted`.`persisted`.`crefutil`.`_Defer``

class documentation

`class _Defer(Deferred[object], NotKnown): (source)`

Constructor: `_Defer()`

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Undocumented

Method | `__init__` | Initialize a `Deferred`.
Method | `__setitem__` | Undocumented
Method | `addDependant` | Undocumented
Class Variable | `wasset` | Undocumented

Inherited from `Deferred`:

Class Method | `fromCoroutine` | Schedule the execution of a coroutine that awaits on `Deferred`s, wrapping it in a `Deferred` that will fire on success/failure of the coroutine.
Class Method | `fromFuture` | Adapt a `Future` to a `Deferred`.
Method | `__init_subclass__` | Undocumented
Method | `__iter__` | Undocumented
Method | `__str__` | Return a string representation of this `Deferred`.
Method | `addBoth` | Convenience method for adding a single callable as both a callback and an errback.
Method | `addCallback` | Convenience method for adding just a callback.
Method | `addCallbacks` | Add a pair of callbacks (success and error) to this `Deferred`.
Method | `addErrback` | Convenience method for adding just an errback.
Method | `addTimeout` | Time out this `Deferred` by scheduling it to be cancelled after `timeout` seconds.
Method | `asFuture` | Adapt this `Deferred` into a `Future` which is bound to `loop`.
Method | `callback` | Run all success callbacks that have been added to this `Deferred`.
Method | `cancel` | Cancel this `Deferred`.
Method | `chainDeferred` | Chain another `Deferred` to this `Deferred`.
Method | `errback` | Run all error callbacks that have been added to this `Deferred`.
Method | `pause` | Stop processing on a `Deferred` until `unpause`() is called.
Method | `unpause` | Process all callbacks made since `pause`() was called.
Class Variable | `debug` | Undocumented
Instance Variable | `called` | A flag which is `False` until either `callback` or `errback` is called and afterwards always `True`.
Instance Variable | `paused` | A counter of how many unmatched `pause` calls have been made on this instance.
Instance Variable | `result` | Undocumented
Property | `callbacks` | Undocumented
Method | `_continuation` | Build a tuple of callback and errback with `_Sentinel._CONTINUE`.
Method | `_runCallbacks` | Run the chain of callbacks once a result is available.
Method | `_startRunCallbacks` | Undocumented
Instance Variable | `_callbacks` | Undocumented
Instance Variable | `_canceller` | Undocumented
Instance Variable | `_chainedTo` | If this `Deferred` is waiting for the result of another `Deferred`, this is a reference to the other Deferred. Otherwise, `None`.
Instance Variable | `_debugInfo` | Undocumented
Instance Variable | `_runningCallbacks` | A flag which is `True` while this instance is executing its callback chain, used to stop recursive execution of `_runCallbacks`
Instance Variable | `_suppressAlreadyCalled` | A flag used by the cancellation mechanism which is `True` if the Deferred has no canceller and has been cancelled, `False` otherwise. If `True`, it can be expected that `callback` or `errback` will eventually be called and the result should be silently discarded.

Inherited from `NotKnown` (via `Deferred`):

Method | `__hash__` | Undocumented
Method | `resolveDependants` | Undocumented
Instance Variable | `dependants` | Undocumented
Instance Variable | `resolved` | Undocumented
Instance Variable | `resolvedObject` | Undocumented

def __init__(self): (source)
overrides `twisted.internet.defer.Deferred.__init__`

Initialize a `Deferred`.

Parameters

canceller:a 1-argument callable which takes a `Deferred`. The return result is ignored.

a callable used to stop the pending operation scheduled by this `Deferred` when `Deferred.cancel` is invoked. The canceller will be passed the deferred whose cancellation is requested (i.e., `self`).

If a canceller is not given, or does not invoke its argument's `callback` or `errback` method, `Deferred.cancel` will invoke `Deferred.errback` with a `CancelledError`.

Note that if a canceller is not given, `callback` or `errback` may still be invoked exactly once, even though defer.py will have already invoked `errback`, as described above. This allows clients of code which returns a `Deferred` to cancel it without requiring the `Deferred` instantiator to provide any specific implementation support for cancellation. New in 10.1.

def __setitem__(self, n, obj): (source)

Undocumented

def addDependant(self, dep, key): (source)
overrides `twisted.persisted.crefutil.NotKnown.addDependant`

Undocumented

wasset: `int` = (source)

Undocumented