[Feature] Force log_prob to return a tensordict when kwargs are passe…

…d to ProbabilisticTensorDictSequential.log_prob

ghstack-source-id: 326d0763c9bbb13b51daac91edca4f0e821adf62
Pull Request resolved: #1146

tensordict/nn/probabilistic.py

@@ -422,21 +422,49 @@ def log_prob(
                 if dist.aggregate_probabilities is not None:
                     aggregate_probabilities_inp = dist.aggregate_probabilities
                 else:
-                    # TODO: warning
+                    warnings.warn(
+                        f"aggregate_probabilities wasn't defined in the {type(self).__name__} instance. "
+                        f"It couldn't be retrieved from the CompositeDistribution object either. "
+                        f"Currently, the aggregate_probability will be `True` in this case but in a future release "
+                        f"(v0.9) this will change and `aggregate_probabilities` will default to ``False`` such "
+                        f"that log_prob will return a tensordict with the log-prob values. To silence this warning, "
+                        f"pass `aggregate_probabilities` to the {type(self).__name__} constructor, to the distribution kwargs "
+                        f"or to the log-prob method.",
+                        category=DeprecationWarning,
+                    )
                     aggregate_probabilities_inp = False
             else:
                 aggregate_probabilities_inp = aggregate_probabilities
             if inplace is None:
                 if dist.inplace is not None:
                     inplace = dist.inplace
                 else:
-                    # TODO: warning
+                    warnings.warn(
+                        f"inplace wasn't defined in the {type(self).__name__} instance. "
+                        f"It couldn't be retrieved from the CompositeDistribution object either. "
+                        f"Currently, the `inplace` will be `True` in this case but in a future release "
+                        f"(v0.9) this will change and `inplace` will default to ``False`` such "
+                        f"that log_prob will return a new tensordict containing only the log-prob values. To silence this warning, "
+                        f"pass `inplace` to the {type(self).__name__} constructor, to the distribution kwargs "
+                        f"or to the log-prob method.",
+                        category=DeprecationWarning,
+                    )
                     inplace = True
             if include_sum is None:
                 if dist.include_sum is not None:
                     include_sum = dist.include_sum
                 else:
-                    # TODO: warning
+                    warnings.warn(
+                        f"include_sum wasn't defined in the {type(self).__name__} instance. "
+                        f"It couldn't be retrieved from the CompositeDistribution object either. "
+                        f"Currently, the `include_sum` will be `True` in this case but in a future release "
+                        f"(v0.9) this will change and `include_sum` will default to ``False`` such "
+                        f"that log_prob will return a new tensordict containing only the leaf log-prob values. "
+                        f"To silence this warning, "
+                        f"pass `include_sum` to the {type(self).__name__} constructor, to the distribution kwargs "
+                        f"or to the log-prob method.",
+                        category=DeprecationWarning,
+                    )
                     include_sum = True
             lp = dist.log_prob(
                 tensordict,
@@ -446,6 +474,7 @@ def log_prob(
             )
             if is_tensor_collection(lp) and aggregate_probabilities is None:
                 return lp.get(dist.log_prob_key)
+            return lp
         else:
             return dist.log_prob(tensordict.get(self.out_keys[0]))
 
@@ -1027,8 +1056,9 @@ def log_prob(
     ):
         """Returns the log-probability of the input tensordict.
 
-        If `return_composite` is ``True`` and the distribution is a :class:`~tensordict.nn.CompositeDistribution`,
-        this method will return the log-probability of the entire composite distribution.
+        If `self.return_composite` is ``True`` and the distribution is a :class:`~tensordict.nn.CompositeDistribution`,
+        or if any of :attr:`aggregate_probabilities`, :attr:`inplace` or :attr:`include_sum` this method will return
+        the log-probability of the entire composite distribution.
 
         Otherwise, it will only consider the last probabilistic module in the sequence.
 
@@ -1069,7 +1099,13 @@ def log_prob(
             tensordict_inp = tensordict
         if dist is None:
             dist = self.get_dist(tensordict_inp)
-        if self.return_composite and isinstance(dist, CompositeDistribution):
+        return_composite = (
+            self.return_composite
+            or (aggregate_probabilities is not None)
+            or (inplace is not None)
+            or (include_sum is not None)
+        )
+        if return_composite and isinstance(dist, CompositeDistribution):
             # Check the values within the dist - if not set, choose defaults
             if aggregate_probabilities is None:
                 if self.aggregate_probabilities is not None:

test/test_nn.py

@@ -2930,7 +2930,17 @@ def test_prob_module(self, interaction, return_log_prob, map_names):
             assert key_logprob1 in sample
         assert all(key in sample for key in module.out_keys)
         sample_clone = sample.clone()
-        lp = module.log_prob(sample_clone)
+        with pytest.warns(
+            DeprecationWarning,
+            match="aggregate_probabilities wasn't defined in the ProbabilisticTensorDictModule",
+        ), pytest.warns(
+            DeprecationWarning,
+            match="inplace wasn't defined in the ProbabilisticTensorDictModule",
+        ), pytest.warns(
+            DeprecationWarning,
+            match="include_sum wasn't defined in the ProbabilisticTensorDictModule",
+        ):
+            lp = module.log_prob(sample_clone)
         assert isinstance(lp, torch.Tensor)
         if return_log_prob:
             torch.testing.assert_close(
@@ -3077,7 +3087,17 @@ def test_prob_module_seq(self, interaction, return_log_prob, ordereddict):
         assert isinstance(dist, CompositeDistribution)
 
         sample_clone = sample.clone()
-        lp = module.log_prob(sample_clone)
+        with pytest.warns(
+            DeprecationWarning,
+            match="aggregate_probabilities wasn't defined in the ProbabilisticTensorDictModule",
+        ), pytest.warns(
+            DeprecationWarning,
+            match="inplace wasn't defined in the ProbabilisticTensorDictModule",
+        ), pytest.warns(
+            DeprecationWarning,
+            match="include_sum wasn't defined in the ProbabilisticTensorDictModule",
+        ):
+            lp = module.log_prob(sample_clone)
 
         if return_log_prob:
             torch.testing.assert_close(