Add weakref Python types

newsfragments/3835.added.md

@@ -0,0 +1 @@
+Add `PyWeakref`, `PyWeakrefReference` and `PyWeakrefProxy`.

src/prelude.rs

@@ -49,3 +49,4 @@ pub use crate::types::string::PyStringMethods;
 pub use crate::types::traceback::PyTracebackMethods;
 pub use crate::types::tuple::PyTupleMethods;
 pub use crate::types::typeobject::PyTypeMethods;
+pub use crate::types::weakref::PyWeakrefMethods;

src/types/mod.rs

@@ -47,6 +47,7 @@ pub use self::string::{PyString, PyString as PyUnicode, PyStringMethods};
 pub use self::traceback::{PyTraceback, PyTracebackMethods};
 pub use self::tuple::{PyTuple, PyTupleMethods};
 pub use self::typeobject::{PyType, PyTypeMethods};
+pub use self::weakref::{PyWeakref, PyWeakrefMethods, PyWeakrefProxy, PyWeakrefReference};
 
 /// Iteration over Python collections.
 ///
@@ -365,3 +366,4 @@ pub(crate) mod string;
 pub(crate) mod traceback;
 pub(crate) mod tuple;
 pub(crate) mod typeobject;
+pub(crate) mod weakref;