deprecate __version__ (#2772)

CHANGES.rst

@@ -6,6 +6,8 @@ Version 3.0.0
 Unreleased
 
 -   Remove previously deprecated code. :pr:`2768`
+-   Deprecate the ``__version__`` attribute. Use feature detection, or
+    ``importlib.metadata.version("werkzeug")``, instead. :issue:`2770`
 -   ``generate_password_hash`` uses scrypt by default. :issue:`2769`
 
 

pyproject.toml

@@ -1,5 +1,6 @@
 [project]
 name = "Werkzeug"
+version = "3.0.0.dev"
 description = "The comprehensive WSGI web application library."
 readme = "README.rst"
 license = {file = "LICENSE.rst"}
@@ -19,7 +20,6 @@ classifiers = [
 ]
 requires-python = ">=3.8"
 dependencies = ["MarkupSafe>=2.1.1"]
-dynamic = ["version"]
 
 [project.urls]
 Donate = "https://palletsprojects.com/donate"

src/werkzeug/__init__.py

@@ -1,6 +1,25 @@
+from __future__ import annotations
+
+import typing as t
+
 from .serving import run_simple as run_simple
 from .test import Client as Client
 from .wrappers import Request as Request
 from .wrappers import Response as Response
 
-__version__ = "3.0.0.dev"
+
+def __getattr__(name: str) -> t.Any:
+    if name == "__version__":
+        import importlib.metadata
+        import warnings
+
+        warnings.warn(
+            "The '__version__' attribute is deprecated and will be removed in"
+            " Werkzeug 3.1. Use feature detection or"
+            " 'importlib.metadata.version(\"werkzeug\")' instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return importlib.metadata.version("werkzeug")
+
+    raise AttributeError(name)

src/werkzeug/serving.py

@@ -154,9 +154,7 @@ class WSGIRequestHandler(BaseHTTPRequestHandler):
 
     @property
     def server_version(self) -> str:  # type: ignore
-        from . import __version__
-
-        return f"Werkzeug/{__version__}"
+        return self.server._server_version
 
     def make_environ(self) -> WSGIEnvironment:
         request_url = urlsplit(self.path)
@@ -796,6 +794,10 @@ def __init__(
         else:
             self.ssl_context = None
 
+        import importlib.metadata
+
+        self._server_version = f"Werkzeug/{importlib.metadata.version('werkzeug')}"
+
     def log(self, type: str, message: str, *args: t.Any) -> None:
         _log(type, message, *args)