reference/generated/tensordict.TensorDictBase.setdefault

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TensorDictBase.setdefault

TensorDictBase.setdefault(key: NestedKey, default: Tensor | TensorCollection | Any, inplace: bool = False) → Tensor | TensorCollection

Returns the entry at key, after writing default there if the key is missing.

As for dict.setdefault(), an existing entry is not changed. The result is read with get(), so a non-tensor entry returns its NonTensorData.

Parameters:

• key (NestedKey) – the key of the entry.

• default (Tensor, TensorDictBase or any object) – the value written if the key is missing.

• inplace (bool, optional) – passed to set() when default is written. Defaults to False.

Raises:

RuntimeError – if the key is missing and the tensordict is locked, or if the leading dimensions of default do not match the batch size.

Examples

>>> import torch
>>> from tensordict import TensorDict
>>> td = TensorDict({}, batch_size=[3])
>>> td.setdefault("a", torch.zeros(3))
tensor([0., 0., 0.])
>>> td.setdefault("a", torch.ones(3))  # "a" exists: not changed
tensor([0., 0., 0.])

Every tensordict class and every tensorclass has this method. For the other methods, see Methods by task.

Tutorials that use setdefault

Getting, setting, and nesting keys

Getting, setting, and nesting keys