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venv/lib/python3.12/site-packages/jax/_src/lazy_loader.py

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+# Copyright 2022 The JAX Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""A LazyLoader class."""
+
+from collections.abc import Callable, Sequence
+import importlib
+import sys
+from typing import Any
+
+
+def attach(package_name: str, submodules: Sequence[str]) -> tuple[
+    Callable[[str], Any],
+    Callable[[], list[str]],
+    list[str],
+]:
+  """Lazily loads submodules of a package.
+
+  Returns:
+    A tuple of ``__getattr__``, ``__dir__`` function and ``__all__`` --
+    a list of available global names, which can be used to replace the
+    corresponding definitions in the package.
+
+  Raises:
+    RuntimeError: If the ``__name__`` of the caller cannot be determined.
+  """
+  owner_name = sys._getframe(1).f_globals.get("__name__")
+  if owner_name is None:
+    raise RuntimeError("Cannot determine the ``__name__`` of the caller.")
+
+  __all__ = list(submodules)
+
+  def __getattr__(name: str) -> Any:
+    if name in submodules:
+      value = importlib.import_module(f"{package_name}.{name}")
+      # Update module-level globals to avoid calling ``__getattr__`` again
+      # for this ``name``.
+      assert owner_name is not None  # pyrefly#40
+      setattr(sys.modules[owner_name], name, value)
+      return value
+    raise AttributeError(f"module '{package_name}' has no attribute '{name}'")
+
+  def __dir__() -> list[str]:
+    return __all__
+
+  return __getattr__, __dir__, __all__