structure saas with tools

.venv/lib/python3.10/site-packages/graphviz/parameters/engines.py

@@ -0,0 +1,62 @@
+"""Rendering engine parameter handling."""
+
+import typing
+
+from . import base
+
+__all__ = ['ENGINES', 'verify_engine', 'Engine']
+
+ENGINES = {'dot',  # https://www.graphviz.org/pdf/dot.1.pdf
+           'neato',
+           'twopi',
+           'circo',
+           'fdp',
+           'sfdp',
+           'patchwork',
+           'osage'}
+
+DEFAULT_ENGINE = 'dot'
+
+REQUIRED = True
+
+
+def verify_engine(engine: str, *, required: bool = REQUIRED) -> None:
+    if engine is None:
+        if required:
+            raise ValueError('missing engine')
+    elif engine.lower() not in ENGINES:
+        raise ValueError(f'unknown engine: {engine!r}'
+                         f' (must be one of {sorted(ENGINES)})')
+
+
+class Engine(base.ParameterBase):
+    """Rendering engine parameter with ``'dot''`` default."""
+
+    _engine = DEFAULT_ENGINE
+
+    _verify_engine = staticmethod(verify_engine)
+
+    def __init__(self, *, engine: typing.Optional[str] = None, **kwargs) -> None:
+        super().__init__(**kwargs)
+
+        if engine is not None:
+            self.engine = engine
+
+    def _copy_kwargs(self, **kwargs):
+        """Return the kwargs to create a copy of the instance."""
+        engine = self._getattr_from_dict('_engine')
+        if engine is not None:
+            kwargs['engine'] = engine
+        return super()._copy_kwargs(**kwargs)
+
+    @property
+    def engine(self) -> str:
+        """The layout engine used for rendering
+            (``'dot'``, ``'neato'``, ...)."""
+        return self._engine
+
+    @engine.setter
+    def engine(self, engine: str) -> None:
+        engine = engine.lower()
+        self._verify_engine(engine)
+        self._engine = engine