[BugFix] Fixed import for importlib (#1914)

Co-authored-by: vmoens <[email protected]>

.github/workflows/build-wheels-m1.yml

@@ -19,12 +19,12 @@ permissions:
 
 jobs:
   generate-matrix:
-    uses: pytorch/test-infra/.github/workflows/generate_binary_build_matrix.yml@main
+    uses: pytorch/test-infra/.github/workflows/generate_binary_build_matrix.yml@Remove-Builds-Limits-for-Testing
     with:
       package-type: wheel
       os: macos-arm64
       test-infra-repository: pytorch/test-infra
-      test-infra-ref: main
+      test-infra-ref: Remove-Builds-Limits-for-Testing
   build:
     needs: generate-matrix
     strategy:

test/smoke_test.py

@@ -14,3 +14,5 @@ def test_imports():
     from torchrl.envs.gym_like import GymLikeEnv  # noqa: F401
     from torchrl.modules import SafeModule  # noqa: F401
     from torchrl.objectives.common import LossModule  # noqa: F401
+
+    PrioritizedReplayBuffer(alpha=1.1, beta=1.1)

torchrl/_extension.py

@@ -3,18 +3,17 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
-import importlib
+import importlib.util
 import warnings
 
 
 def is_module_available(*modules: str) -> bool:
-    r"""Returns if a top-level module with :attr:`name` exists *without** importing it.
+    """Returns if a top-level module with :attr:`name` exists *without** importing it.
 
     This is generally safer than try-catch block around a
     `import X`. It avoids third party libraries breaking assumptions of some of
     our tests, e.g., setting multiprocessing start method when imported
     (see librosa/#747, torchvision/#544).
-
     """
     return all(importlib.util.find_spec(m) is not None for m in modules)