chore+feat(python-utils): update to pyo3 0.27, introduce helpers like FromPyObjectViaParse and IntoPyObjectViaDisplay before I make macros that can complement or replace them

python-utils/src/none.rs

@@ -0,0 +1,27 @@
+use std::convert::Infallible;
+
+use pyo3::{types::PyNone, Borrowed, FromPyObject, IntoPyObject, PyAny, PyErr, Python};
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct IsNone;
+
+impl<'a, 'py> FromPyObject<'a, 'py> for IsNone {
+    type Error = PyErr;
+
+    fn extract(ob: Borrowed<'a, 'py, PyAny>) -> Result<Self, Self::Error> {
+        ob.cast::<PyNone>()?;
+        Ok(IsNone)
+    }
+}
+
+impl<'py> IntoPyObject<'py> for IsNone {
+    type Target = PyNone;
+
+    type Output = Borrowed<'py, 'py, Self::Target>;
+
+    type Error = Infallible;
+
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        Ok(PyNone::get(py))
+    }
+}