Fix ModuleNotFoundError if attrs is not installed

HISTORY.md

@@ -1,5 +1,9 @@
 # erdantic Changelog
 
+## v1.0.1 (2024-04-10)
+
+- Fixed `ModuleNotFoundError` when importing from `erdantic.examples` without attrs installed.
+
 ## v1.0.0.post2 (2024-04-10)
 
 - Fixed missing LICENSE file in sdist.

erdantic/examples/__init__.py

@@ -1,10 +1,18 @@
 """Example data model classes."""
 
-from erdantic.examples import attrs, dataclasses, pydantic, pydantic_v1
+from erdantic.examples import dataclasses, pydantic, pydantic_v1
 
 __all__ = [
-    "attrs",
     "dataclasses",
     "pydantic",
     "pydantic_v1",
 ]
+
+try:
+    from erdantic.examples import attrs
+
+    attrs
+    __all__.append("attrs")
+except ModuleNotFoundError as e:
+    if e.name != "attrs":
+        raise

noxfile.py

@@ -106,7 +106,9 @@ def test_wheel(session, extras):
     else:
         session.install(str(wheel_path) + extras)
     session.run("python", "-m", "erdantic", "--version")
-    session.run("python", "-c", "import erdantic; print(erdantic.list_plugins())")
+    session.run(
+        "python", "-c", "import erdantic; import erdantic.examples; print(erdantic.list_plugins())"
+    )
 
 
 @nox.session(venv_backend="mamba|conda", python="3.12", reuse_venv=False)
@@ -120,6 +122,9 @@ def test_sdist(session):
     else:
         session.install(sdist_path)
     session.run("python", "-m", "erdantic", "--version")
+    session.run(
+        "python", "-c", "import erdantic; import erdantic.examples; print(erdantic.list_plugins())"
+    )
 
 
 def _docs_base(session):