Py/PyAny: remove PartialEq impl and add is() (#2183)

CHANGELOG.md

@@ -35,7 +35,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add `PyMapping::contains` method (`in` operator for `PyMapping`). [#2133](https://github.com/PyO3/pyo3/pull/2133)
 - Add garbage collection magic methods `__traverse__` and `__clear__` to `#[pymethods]`. [#2159](https://github.com/PyO3/pyo3/pull/2159)
 - Add support for `from_py_with` on struct tuples and enums to override the default from-Python conversion. [#2181](https://github.com/PyO3/pyo3/pull/2181)
-- Add `eq`, `ne`, `lt`, `le`, `gt`, `ge` methods to `PyAny` that wrap `rich_compare`.
+- Add `eq`, `ne`, `lt`, `le`, `gt`, `ge` methods to `PyAny` that wrap `rich_compare`. [#2175](https://github.com/PyO3/pyo3/pull/2175)
+- Add `Py::is` and `PyAny::is` methods to check for object identity. [#2183](https://github.com/PyO3/pyo3/pull/2183)
 
 ### Changed
 
@@ -81,7 +82,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Removed
 
 - Remove all functionality deprecated in PyO3 0.14. [#2007](https://github.com/PyO3/pyo3/pull/2007)
-- Remove `Default` impl for `PyMethodDef` [2166](https://github.com/PyO3/pyo3/pull/2166)
+- Remove `Default` impl for `PyMethodDef`. [#2166](https://github.com/PyO3/pyo3/pull/2166)
+- Remove `PartialEq` impl for `Py` and `PyAny` (use the new `is()` instead). [#2183](https://github.com/PyO3/pyo3/pull/2183)
 
 ### Fixed
 

guide/src/migration.md

@@ -62,6 +62,19 @@ impl MyClass {
 }
 ```
 
+### Removed `PartialEq` for object wrappers
+
+The Python object wrappers `Py` and `PyAny` had implementations of `PartialEq`
+so that `object_a == object_b` would compare the Python objects for pointer
+equality, which corresponds to the `is` operator, not the `==` operator in
+Python.  This has been removed in favor of a new method: use
+`object_a.is(object_b)`.  This also has the advantage of not requiring the same
+wrapper type for `object_a` and `object_b`; you can now directly compare a
+`Py<T>` with a `&PyAny` without having to convert.
+
+To check for Python object equality (the Python `==` operator), use the new
+method `eq()`.
+
 ### Container magic methods now match Python behavior
 
 In PyO3 0.15, `__getitem__`, `__setitem__` and `__delitem__` in `#[pymethods]` would generate only the _mapping_ implementation for a `#[pyclass]`. To match the Python behavior, these methods now generate both the _mapping_ **and** _sequence_ implementations.

src/conversion.rs

@@ -561,7 +561,7 @@ mod tests {
         Python::with_gil(|py| {
             let list = PyList::new(py, &[1, 2, 3]);
             let val = unsafe { <PyList as PyTryFrom>::try_from_unchecked(list.as_ref()) };
-            assert_eq!(list, val);
+            assert!(list.is(val));
         });
     }
 

src/err/mod.rs

@@ -187,7 +187,7 @@ impl PyErr {
     ///
     /// Python::with_gil(|py| {
     ///     let err: PyErr = PyTypeError::new_err(("some type error",));
-    ///     assert_eq!(err.get_type(py), PyType::new::<PyTypeError>(py));
+    ///     assert!(err.get_type(py).is(PyType::new::<PyTypeError>(py)));
     /// });
     /// ```
     pub fn get_type<'py>(&'py self, py: Python<'py>) -> &'py PyType {
@@ -231,7 +231,7 @@ impl PyErr {
     ///
     /// Python::with_gil(|py| {
     ///     let err = PyTypeError::new_err(("some type error",));
-    ///     assert_eq!(err.traceback(py), None);
+    ///     assert!(err.traceback(py).is_none());
     /// });
     /// ```
     pub fn traceback<'py>(&'py self, py: Python<'py>) -> Option<&'py PyTraceback> {
@@ -469,9 +469,12 @@ impl PyErr {
     /// Python::with_gil(|py| {
     ///     let err: PyErr = PyTypeError::new_err(("some type error",));
     ///     let err_clone = err.clone_ref(py);
-    ///     assert_eq!(err.get_type(py), err_clone.get_type(py));
-    ///     assert_eq!(err.value(py), err_clone.value(py));
-    ///     assert_eq!(err.traceback(py), err_clone.traceback(py));
+    ///     assert!(err.get_type(py).is(err_clone.get_type(py)));
+    ///     assert!(err.value(py).is(err_clone.value(py)));
+    ///     match err.traceback(py) {
+    ///         None => assert!(err_clone.traceback(py).is_none()),
+    ///         Some(tb) => assert!(err_clone.traceback(py).unwrap().is(tb)),
+    ///     }
     /// });
     /// ```
     #[inline]
@@ -706,7 +709,7 @@ fn exceptions_must_derive_from_base_exception(py: Python) -> PyErr {
 mod tests {
     use super::PyErrState;
     use crate::exceptions;
-    use crate::{PyErr, Python};
+    use crate::{AsPyPointer, PyErr, Python};
 
     #[test]
     fn no_error() {
@@ -857,16 +860,22 @@ mod tests {
     fn deprecations() {
         let err = exceptions::PyValueError::new_err("an error");
         Python::with_gil(|py| {
-            assert_eq!(err.ptype(py), err.get_type(py));
-            assert_eq!(err.pvalue(py), err.value(py));
-            assert_eq!(err.instance(py), err.value(py));
-            assert_eq!(err.ptraceback(py), err.traceback(py));
+            assert_eq!(err.ptype(py).as_ptr(), err.get_type(py).as_ptr());
+            assert_eq!(err.pvalue(py).as_ptr(), err.value(py).as_ptr());
+            assert_eq!(err.instance(py).as_ptr(), err.value(py).as_ptr());
+            assert_eq!(
+                err.ptraceback(py).map(|t| t.as_ptr()),
+                err.traceback(py).map(|t| t.as_ptr())
+            );
 
             assert_eq!(
-                err.clone_ref(py).into_instance(py).as_ref(py),
-                err.value(py)
+                err.clone_ref(py).into_instance(py).as_ref(py).as_ptr(),
+                err.value(py).as_ptr()
+            );
+            assert_eq!(
+                PyErr::from_instance(err.value(py)).value(py).as_ptr(),
+                err.value(py).as_ptr()
             );
-            assert_eq!(PyErr::from_instance(err.value(py)).value(py), err.value(py));
         });
     }
 }

src/impl_/extract_argument.rs

@@ -102,7 +102,7 @@ pub fn from_py_with_with_default<'py, T>(
 #[doc(hidden)]
 #[cold]
 pub fn argument_extraction_error(py: Python, arg_name: &str, error: PyErr) -> PyErr {
-    if error.get_type(py) == PyTypeError::type_object(py) {
+    if error.get_type(py).is(PyTypeError::type_object(py)) {
         let remapped_error =
             PyTypeError::new_err(format!("argument '{}': {}", arg_name, error.value(py)));
         remapped_error.set_cause(py, error.cause(py));

src/instance.rs

@@ -463,6 +463,15 @@ where
 }
 
 impl<T> Py<T> {
+    /// Returns whether `self` and `other` point to the same object. To compare
+    /// the equality of two objects (the `==` operator), use [`eq`](PyAny::eq).
+    ///
+    /// This is equivalent to the Python expression `self is other`.
+    #[inline]
+    pub fn is<U: AsPyPointer>(&self, o: &U) -> bool {
+        self.as_ptr() == o.as_ptr()
+    }
+
     /// Gets the reference count of the `ffi::PyObject` pointer.
     #[inline]
     pub fn get_refcnt(&self, _py: Python) -> isize {
@@ -829,13 +838,6 @@ where
     }
 }
 
-impl<T> PartialEq for Py<T> {
-    #[inline]
-    fn eq(&self, o: &Py<T>) -> bool {
-        self.0 == o.0
-    }
-}
-
 /// If the GIL is held this increments `self`'s reference count.
 /// Otherwise this registers the [`Py`]`<T>` instance to have its reference count
 /// incremented the next time PyO3 acquires the GIL.

src/types/any.rs

@@ -87,6 +87,15 @@ impl PyAny {
         <T as PyTryFrom>::try_from(self)
     }
 
+    /// Returns whether `self` and `other` point to the same object. To compare
+    /// the equality of two objects (the `==` operator), use [`eq`](PyAny::eq).
+    ///
+    /// This is equivalent to the Python expression `self is other`.
+    #[inline]
+    pub fn is<T: AsPyPointer>(&self, other: &T) -> bool {
+        self.as_ptr() == other.as_ptr()
+    }
+
     /// Determines whether this object has the given attribute.
     ///
     /// This is equivalent to the Python expression `hasattr(self, attr_name)`.

src/types/boolobject.rs

@@ -69,7 +69,7 @@ mod tests {
             assert!(PyBool::new(py, true).is_true());
             let t: &PyAny = PyBool::new(py, true).into();
             assert!(t.extract::<bool>().unwrap());
-            assert_eq!(true.to_object(py), PyBool::new(py, true).into());
+            assert!(true.to_object(py).is(PyBool::new(py, true)));
         });
     }
 
@@ -79,7 +79,7 @@ mod tests {
             assert!(!PyBool::new(py, false).is_true());
             let t: &PyAny = PyBool::new(py, false).into();
             assert!(!t.extract::<bool>().unwrap());
-            assert_eq!(false.to_object(py), PyBool::new(py, false).into());
+            assert!(false.to_object(py).is(PyBool::new(py, false)));
         });
     }
 }

src/types/dict.rs

@@ -387,7 +387,7 @@ mod tests {
         Python::with_gil(|py| {
             let dict = [(7, 32)].into_py_dict(py);
             assert_eq!(32, dict.get_item(7i32).unwrap().extract::<i32>().unwrap());
-            assert_eq!(None, dict.get_item(8i32));
+            assert!(dict.get_item(8i32).is_none());
             let map: HashMap<i32, i32> = [(7, 32)].iter().cloned().collect();
             assert_eq!(map, dict.extract().unwrap());
             let map: BTreeMap<i32, i32> = [(7, 32)].iter().cloned().collect();
@@ -426,7 +426,7 @@ mod tests {
 
             let ndict = dict.copy().unwrap();
             assert_eq!(32, ndict.get_item(7i32).unwrap().extract::<i32>().unwrap());
-            assert_eq!(None, ndict.get_item(8i32));
+            assert!(ndict.get_item(8i32).is_none());
         });
     }
 
@@ -464,7 +464,7 @@ mod tests {
             let ob = v.to_object(py);
             let dict = <PyDict as PyTryFrom>::try_from(ob.as_ref(py)).unwrap();
             assert_eq!(32, dict.get_item(7i32).unwrap().extract::<i32>().unwrap());
-            assert_eq!(None, dict.get_item(8i32));
+            assert!(dict.get_item(8i32).is_none());
         });
     }
 
@@ -527,7 +527,7 @@ mod tests {
             let dict = <PyDict as PyTryFrom>::try_from(ob.as_ref(py)).unwrap();
             assert!(dict.del_item(7i32).is_ok());
             assert_eq!(0, dict.len());
-            assert_eq!(None, dict.get_item(7i32));
+            assert!(dict.get_item(7i32).is_none());
         });
     }
 

src/types/iterator.rs

@@ -213,7 +213,7 @@ def fibonacci(target):
         Python::with_gil(|py| {
             let obj: Py<PyAny> = vec![10, 20].to_object(py).as_ref(py).iter().unwrap().into();
             let iter: &PyIterator = PyIterator::try_from(obj.as_ref(py)).unwrap();
-            assert_eq!(obj, iter.into());
+            assert!(obj.is(iter));
         });
     }
 

src/types/mod.rs

@@ -64,15 +64,6 @@ macro_rules! pyobject_native_type_base(
                 unsafe { $crate::PyObject::from_borrowed_ptr(py, self.as_ptr()) }
             }
         }
-
-        impl<$($generics,)*> ::std::cmp::PartialEq for $name {
-            #[inline]
-            fn eq(&self, o: &$name) -> bool {
-                use $crate::AsPyPointer;
-
-                self.as_ptr() == o.as_ptr()
-            }
-        }
     };
 );
 

src/types/sequence.rs

@@ -725,11 +725,11 @@ mod tests {
             let seq = ob.cast_as::<PySequence>(py).unwrap();
             let rep_seq = seq.in_place_repeat(3).unwrap();
             assert_eq!(6, seq.len().unwrap());
-            assert_eq!(seq, rep_seq);
+            assert!(seq.is(rep_seq));
 
             let conc_seq = seq.in_place_concat(seq).unwrap();
             assert_eq!(12, seq.len().unwrap());
-            assert_eq!(seq, conc_seq);
+            assert!(seq.is(conc_seq));
         });
     }
 

src/types/string.rs

@@ -504,7 +504,7 @@ mod tests {
             let data = unsafe { s.data().unwrap() };
             assert_eq!(data, PyStringData::Ucs1(b"f\xfe"));
             let err = data.to_string(py).unwrap_err();
-            assert_eq!(err.get_type(py), PyUnicodeDecodeError::type_object(py));
+            assert!(err.get_type(py).is(PyUnicodeDecodeError::type_object(py)));
             assert!(err
                 .to_string()
                 .contains("'utf-8' codec can't decode byte 0xfe in position 1"));
@@ -546,7 +546,7 @@ mod tests {
             let data = unsafe { s.data().unwrap() };
             assert_eq!(data, PyStringData::Ucs2(&[0xff22, 0xd800]));
             let err = data.to_string(py).unwrap_err();
-            assert_eq!(err.get_type(py), PyUnicodeDecodeError::type_object(py));
+            assert!(err.get_type(py).is(PyUnicodeDecodeError::type_object(py)));
             assert!(err
                 .to_string()
                 .contains("'utf-16' codec can't decode bytes in position 0-3"));
@@ -585,7 +585,7 @@ mod tests {
             let data = unsafe { s.data().unwrap() };
             assert_eq!(data, PyStringData::Ucs4(&[0x20000, 0xd800]));
             let err = data.to_string(py).unwrap_err();
-            assert_eq!(err.get_type(py), PyUnicodeDecodeError::type_object(py));
+            assert!(err.get_type(py).is(PyUnicodeDecodeError::type_object(py)));
             assert!(err
                 .to_string()
                 .contains("'utf-32' codec can't decode bytes in position 0-7"));

tests/test_sequence.rs

@@ -279,10 +279,12 @@ fn test_generic_list_set() {
     let list = PyCell::new(py, GenericList { items: vec![] }).unwrap();
 
     py_run!(py, list, "list.items = [1, 2, 3]");
-    assert_eq!(
-        list.borrow().items,
-        vec![1.to_object(py), 2.to_object(py), 3.to_object(py)]
-    );
+    assert!(list
+        .borrow()
+        .items
+        .iter()
+        .zip(&[1u32, 2, 3])
+        .all(|(a, b)| a.as_ref(py).eq(&b.into_py(py)).unwrap()));
 }
 
 #[pyclass]

tests/test_sequence_pyproto.rs

@@ -263,10 +263,12 @@ fn test_generic_list_set() {
     let list = PyCell::new(py, GenericList { items: vec![] }).unwrap();
 
     py_run!(py, list, "list.items = [1, 2, 3]");
-    assert_eq!(
-        list.borrow().items,
-        vec![1.to_object(py), 2.to_object(py), 3.to_object(py)]
-    );
+    assert!(list
+        .borrow()
+        .items
+        .iter()
+        .zip(&[1u32, 2, 3])
+        .all(|(a, b)| a.as_ref(py).eq(&b.into_py(py)).unwrap()));
 }
 
 #[pyclass]

tests/test_serde.rs

@@ -64,7 +64,7 @@ mod test_serde {
         let user: User = serde_json::from_str(serialized).expect("failed to deserialize");
 
         assert_eq!(user.username, "danya");
-        assert_eq!(user.group, None);
+        assert!(user.group.is_none());
         assert_eq!(user.friends.len(), 1usize);
         let friend = user.friends.get(0).unwrap();