Retrieve FromPyObject implementation for &PySequence

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## Unreleased
 
+### Fixed
+
+* `FromPyObject` implementation for `PySequence`. [#827](https://github.com/PyO3/pyo3/pull/827)
+
 ## [0.9.0]
 
 ### Changed

src/types/sequence.rs

@@ -16,6 +16,7 @@ use crate::{FromPyObject, PyTryFrom, ToBorrowedObject};
 #[repr(transparent)]
 pub struct PySequence(PyObject, Unsendable);
 pyobject_native_type_named!(PySequence);
+pyobject_native_type_extract!(PySequence);
 
 impl PySequence {
     /// Returns the number of objects in sequence.

tests/test_methods.rs

@@ -499,3 +499,32 @@ fn test_cfg_attrs() {
 
     py_assert!(py, inst, "not hasattr(inst, 'never_compiled_method')");
 }
+
+#[pyclass]
+#[derive(Default)]
+struct FromSequence {
+    #[pyo3(get)]
+    numbers: Vec<i64>,
+}
+
+#[pymethods]
+impl FromSequence {
+    #[new]
+    fn new(seq: Option<&pyo3::types::PySequence>) -> PyResult<Self> {
+        if let Some(seq) = seq {
+            Ok(FromSequence {
+                numbers: seq.as_ref().extract::<Vec<_>>()?,
+            })
+        } else {
+            Ok(FromSequence::default())
+        }
+    }
+}
+
+#[test]
+fn test_from_sequence() {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    let typeobj = py.get_type::<FromSequence>();
+    py_assert!(py, typeobj, "typeobj(range(0, 4)).numbers == [0, 1, 2, 3]")
+}