second commit

env/lib/python3.11/site-packages/websockets/imports.py

@@ -0,0 +1,100 @@
+from __future__ import annotations
+
+import warnings
+from collections.abc import Iterable
+from typing import Any
+
+
+__all__ = ["lazy_import"]
+
+
+def import_name(name: str, source: str, namespace: dict[str, Any]) -> Any:
+    """
+    Import ``name`` from ``source`` in ``namespace``.
+
+    There are two use cases:
+
+    - ``name`` is an object defined in ``source``;
+    - ``name`` is a submodule of ``source``.
+
+    Neither :func:`__import__` nor :func:`~importlib.import_module` does
+    exactly this. :func:`__import__` is closer to the intended behavior.
+
+    """
+    level = 0
+    while source[level] == ".":
+        level += 1
+        assert level < len(source), "importing from parent isn't supported"
+    module = __import__(source[level:], namespace, None, [name], level)
+    return getattr(module, name)
+
+
+def lazy_import(
+    namespace: dict[str, Any],
+    aliases: dict[str, str] | None = None,
+    deprecated_aliases: dict[str, str] | None = None,
+) -> None:
+    """
+    Provide lazy, module-level imports.
+
+    Typical use::
+
+        __getattr__, __dir__ = lazy_import(
+            globals(),
+            aliases={
+                "<name>": "<source module>",
+                ...
+            },
+            deprecated_aliases={
+                ...,
+            }
+        )
+
+    This function defines ``__getattr__`` and ``__dir__`` per :pep:`562`.
+
+    """
+    if aliases is None:
+        aliases = {}
+    if deprecated_aliases is None:
+        deprecated_aliases = {}
+
+    namespace_set = set(namespace)
+    aliases_set = set(aliases)
+    deprecated_aliases_set = set(deprecated_aliases)
+
+    assert not namespace_set & aliases_set, "namespace conflict"
+    assert not namespace_set & deprecated_aliases_set, "namespace conflict"
+    assert not aliases_set & deprecated_aliases_set, "namespace conflict"
+
+    package = namespace["__name__"]
+
+    def __getattr__(name: str) -> Any:
+        assert aliases is not None  # mypy cannot figure this out
+        try:
+            source = aliases[name]
+        except KeyError:
+            pass
+        else:
+            return import_name(name, source, namespace)
+
+        assert deprecated_aliases is not None  # mypy cannot figure this out
+        try:
+            source = deprecated_aliases[name]
+        except KeyError:
+            pass
+        else:
+            warnings.warn(
+                f"{package}.{name} is deprecated",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            return import_name(name, source, namespace)
+
+        raise AttributeError(f"module {package!r} has no attribute {name!r}")
+
+    namespace["__getattr__"] = __getattr__
+
+    def __dir__() -> Iterable[str]:
+        return sorted(namespace_set | aliases_set | deprecated_aliases_set)
+
+    namespace["__dir__"] = __dir__