# instance.rs - source
Source of the Rust file `/home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/pyo3-0.13.2/src/instance.rs`.
Keywords: rust, rustlang, rust-lang

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    // Copyright (c) 2017-present PyO3 Project and Contributors
    use crate::conversion::{PyTryFrom, ToBorrowedObject};
    use crate::err::{PyDowncastError, PyErr, PyResult};
    use crate::gil;
    use crate::pycell::{PyBorrowError, PyBorrowMutError, PyCell};
    use crate::type_object::PyBorrowFlagLayout;
    use crate::types::{PyDict, PyTuple};
    use crate::{
        ffi, AsPyPointer, FromPyObject, IntoPy, IntoPyPointer, PyAny, PyClass, PyClassInitializer,
        PyRef, PyRefMut, PyTypeInfo, Python, ToPyObject,
    };
    use std::marker::PhantomData;
    use std::mem;
    use std::ptr::NonNull;

    /// Types that are built into the Python interpreter.
    ///
    /// PyO3 is designed in a way that all references to those types are bound
    /// to the GIL, which is why you can get a token from all references of those
    /// types.
    pub unsafe trait PyNativeType: Sized {
        fn py(&self) -> Python {
            unsafe { Python::assume_gil_acquired() }
        }
        /// Cast `&PyAny` to `&Self` without no type checking.
        ///
        /// # Safety
        ///
        /// `obj` must have the same layout as `*const ffi::PyObject` and must be
        /// an instance of a type corresponding to `Self`.
        unsafe fn unchecked_downcast(obj: &PyAny) -> &Self {
            &*(obj.as_ptr() as *const Self)
        }
    }

    /// A Python object of known type T.
    ///
    /// Accessing this object is thread-safe, since any access to its API requires a `Python<'py>` GIL
    /// token. There are a few different ways to use the Python object contained:
    ///  - [`Py::as_ref`](#method.as_ref) to borrow a GIL-bound reference to the contained object.
    ///  - [`Py::borrow`](#method.borrow), [`Py::try_borrow`](#method.try_borrow),
    ///    [`Py::borrow_mut`](#method.borrow_mut), or [`Py::try_borrow_mut`](#method.try_borrow_mut),
    ///    to directly access a `#[pyclass]` value (which has RefCell-like behavior, see
    ///    [the `PyCell` guide entry](https://pyo3.rs/master/class.html#pycell-and-interior-mutability)
    ///    ).
    ///  - Use methods directly on `Py`, such as [`Py::call`](#method.call) and
    ///    [`Py::call_method`](#method.call_method).
    ///
    /// See [the guide](https://pyo3.rs/master/types.html) for an explanation
    /// of the different Python object types.
    #[repr(transparent)]
    pub struct Py<T>(NonNull<ffi::PyObject>, PhantomData<T>);

    unsafe impl<T> Send for Py<T> {}
    unsafe impl<T> Sync for Py<T> {}

    impl<T> Py<T>
    where
        T: PyClass,
    {
        /// Create a new instance `Py<T>` of a `#[pyclass]` on the Python heap.
        pub fn new(py: Python, value: impl Into<PyClassInitializer<T>>) -> PyResult<Py<T>>
        where
            T::BaseLayout: PyBorrowFlagLayout<T::BaseType>,
        {
            let initializer = value.into();
            let obj = initializer.create_cell(py)?;
            let ob = unsafe { Py::from_owned_ptr(py, obj as _) };
            Ok(ob)
        }
    }

    impl<T> Py<T>
    where
        T: PyTypeInfo,
    {
        /// Borrows a GIL-bound reference to the contained `T`. By binding to the GIL lifetime, this
        /// allows the GIL-bound reference to not require `Python` for any of its methods.
        ///
        /// For native types, this reference is `&T`. For pyclasses, this is `&PyCell<T>`.
        ///
        /// # Examples
        /// Get access to `&PyList` from `Py<PyList>`:
        ///
        /// ```
        /// # use pyo3::prelude::*;
        /// # use pyo3::types::PyList;
        /// # Python::with_gil(|py| {
        /// let list: Py<PyList> = PyList::empty(py).into();
        /// let list: &PyList = list.as_ref(py);
        /// assert_eq!(list.len(), 0);
        /// # });
        /// ```
        ///
        /// Get access to `&PyCell<MyClass>` from `Py<MyClass>`:
        ///
        /// ```
        /// # use pyo3::prelude::*;
        /// #[pyclass]
        /// struct MyClass { }
        /// # Python::with_gil(|py| {
        /// let my_class: Py<MyClass> = Py::new(py, MyClass { }).unwrap();
        /// let my_class_cell: &PyCell<MyClass> = my_class.as_ref(py);
        /// assert!(my_class_cell.try_borrow().is_ok());
        /// # });
        /// ```
        pub fn as_ref<'py>(&'py self, _py: Python<'py>) -> &'py T::AsRefTarget {
            let any = self.as_ptr() as *const PyAny;
            unsafe { PyNativeType::unchecked_downcast(&*any) }
        }

        /// Similar to [`as_ref`](#method.as_ref), and also consumes this `Py` and registers the
        /// Python object reference in PyO3's object storage. The reference count for the Python
        /// object will not be decreased until the GIL lifetime ends.
        ///
        /// # Example
        ///
        /// Useful when returning GIL-bound references from functions. In the snippet below, note that
        /// the `'py` lifetime of the input GIL lifetime is also given to the returned reference:
        /// ```
        /// # use pyo3::prelude::*;
        /// fn new_py_any<'py>(py: Python<'py>, value: impl IntoPy<PyObject>) -> &'py PyAny {
        ///     let obj: PyObject = value.into_py(py);
        ///
        ///     // .as_ref(py) would not be suitable here, because a reference to `obj` may not be
        ///     // returned from the function.
        ///     obj.into_ref(py)
        /// }
        /// ```
        pub fn into_ref(self, py: Python) -> &T::AsRefTarget {
            unsafe { py.from_owned_ptr(self.into_ptr()) }
        }
    }

    impl<T> Py<T>
    where
        T: PyClass,
    {
        /// Immutably borrows the value `T`. This borrow lasts untill the returned `PyRef` exists.
        ///
        /// Equivalent to `self.as_ref(py).borrow()` -
        /// see [`PyCell::borrow`](../pycell/struct.PyCell.html#method.borrow)
        ///
        /// # Panics
        /// Panics if the value is currently mutably borrowed. For a non-panicking variant, use
        /// [`try_borrow`](#method.try_borrow).
        pub fn borrow<'py>(&'py self, py: Python<'py>) -> PyRef<'py, T> {
            self.as_ref(py).borrow()
        }

        /// Mutably borrows the value `T`. This borrow lasts untill the returned `PyRefMut` exists.
        ///
        /// Equivalent to `self.as_ref(py).borrow_mut()` -
        /// see [`PyCell::borrow_mut`](../pycell/struct.PyCell.html#method.borrow_mut)
        ///
        /// # Panics
        /// Panics if the value is currently mutably borrowed. For a non-panicking variant, use
        /// [`try_borrow_mut`](#method.try_borrow_mut).
        pub fn borrow_mut<'py>(&'py self, py: Python<'py>) -> PyRefMut<'py, T> {
            self.as_ref(py).borrow_mut()
        }

        /// Immutably borrows the value `T`, returning an error if the value is currently
        /// mutably borrowed. This borrow lasts untill the returned `PyRef` exists.
        ///
        /// This is the non-panicking variant of [`borrow`](#method.borrow).
        ///
        /// Equivalent to `self.as_ref(py).try_borrow()` -
        /// see [`PyCell::try_borrow`](../pycell/struct.PyCell.html#method.try_borrow)
        pub fn try_borrow<'py>(&'py self, py: Python<'py>) -> Result<PyRef<'py, T>, PyBorrowError> {
            self.as_ref(py).try_borrow()
        }

        /// Mutably borrows the value `T`, returning an error if the value is currently borrowed.
        /// This borrow lasts untill the returned `PyRefMut` exists.
        ///
        /// This is the non-panicking variant of [`borrow_mut`](#method.borrow_mut).
        ///
        /// Equivalent to `self.as_ref(py).try_borrow_mut() -
        /// see [`PyCell::try_borrow_mut`](../pycell/struct.PyCell.html#method.try_borrow_mut)
        pub fn try_borrow_mut<'py>(
            &'py self,
            py: Python<'py>,
        ) -> Result<PyRefMut<'py, T>, PyBorrowMutError> {
            self.as_ref(py).try_borrow_mut()
        }
    }

    impl<T> Py<T> {
        /// Gets the reference count of the `ffi::PyObject` pointer.
        #[inline]
        pub fn get_refcnt(&self, _py: Python) -> isize {
            unsafe { ffi::Py_REFCNT(self.0.as_ptr()) }
        }

        /// Clones self by calling `Py_INCREF()` on the ptr.
        #[inline]
        pub fn clone_ref(&self, py: Python) -> Py<T> {
            unsafe { Py::from_borrowed_ptr(py, self.0.as_ptr()) }
        }

        /// Returns whether the object is considered to be None.
        ///
        /// This is equivalent to the Python expression `self is None`.
        pub fn is_none(&self, _py: Python) -> bool {
            unsafe { ffi::Py_None() == self.as_ptr() }
        }

        /// Returns whether the object is considered to be true.
        ///
        /// This is equivalent to the Python expression `bool(self)`.
        pub fn is_true(&self, py: Python) -> PyResult<bool> {
            let v = unsafe { ffi::PyObject_IsTrue(self.as_ptr()) };
            if v == -1 {
                Err(PyErr::fetch(py))
            } else {
                Ok(v != 0)
            }
        }

        /// Extracts some type from the Python object.
        ///
        /// This is a wrapper function around `FromPyObject::extract()`.
        pub fn extract<'p, D>(&'p self, py: Python<'p>) -> PyResult<D>
        where
            D: FromPyObject<'p>,
        {
            FromPyObject::extract(unsafe { py.from_borrowed_ptr(self.as_ptr()) })
        }

        /// Retrieves an attribute value.
        ///
        /// This is equivalent to the Python expression `self.attr_name`.
        pub fn getattr<N>(&self, py: Python, attr_name: N) -> PyResult<PyObject>
        where
            N: ToPyObject,
        {
            attr_name.with_borrowed_ptr(py, |attr_name| unsafe {
                PyObject::from_owned_ptr_or_err(py, ffi::PyObject_GetAttr(self.as_ptr(), attr_name))
            })
        }

        /// Calls the object.
        ///
        /// This is equivalent to the Python expression `self(*args, **kwargs)`.
        pub fn call(
            &self,
            py: Python,
            args: impl IntoPy<Py<PyTuple>>,
            kwargs: Option<&PyDict>,
        ) -> PyResult<PyObject> {
            let args = args.into_py(py).into_ptr();
            let kwargs = kwargs.into_ptr();
            let result = unsafe {
                PyObject::from_owned_ptr_or_err(py, ffi::PyObject_Call(self.as_ptr(), args, kwargs))
            };
            unsafe {
                ffi::Py_XDECREF(args);
                ffi::Py_XDECREF(kwargs);
            }
            result
        }

        /// Calls the object with only positional arguments.
        ///
        /// This is equivalent to the Python expression `self(*args)`.
        pub fn call1(&self, py: Python, args: impl IntoPy<Py<PyTuple>>) -> PyResult<PyObject> {
            self.call(py, args, None)
        }

        /// Calls the object without arguments.
        ///
        /// This is equivalent to the Python expression `self()`.
        pub fn call0(&self, py: Python) -> PyResult<PyObject> {
            cfg_if::cfg_if! {
                // TODO: Use PyObject_CallNoArgs instead after https://bugs.python.org/issue42415.
                // Once the issue is resolved, we can enable this optimization for limited API.
                if #[cfg(all(Py_3_9, not(Py_LIMITED_API)))] {
                    // Optimized path on python 3.9+
                    unsafe {
                        PyObject::from_owned_ptr_or_err(py, ffi::_PyObject_CallNoArg(self.as_ptr()))
                    }
                } else {
                    self.call(py, (), None)
                }
            }
        }

        /// Calls a method on the object.
        ///
        /// This is equivalent to the Python expression `self.name(*args, **kwargs)`.
        pub fn call_method(
            &self,
            py: Python,
            name: &str,
            args: impl IntoPy<Py<PyTuple>>,
            kwargs: Option<&PyDict>,
        ) -> PyResult<PyObject> {
            name.with_borrowed_ptr(py, |name| unsafe {
                let args = args.into_py(py).into_ptr();
                let kwargs = kwargs.into_ptr();
                let ptr = ffi::PyObject_GetAttr(self.as_ptr(), name);
                if ptr.is_null() {
                    return Err(PyErr::fetch(py));
                }
                let result = PyObject::from_owned_ptr_or_err(py, ffi::PyObject_Call(ptr, args, kwargs));
                ffi::Py_DECREF(ptr);
                ffi::Py_XDECREF(args);
                ffi::Py_XDECREF(kwargs);
                result
            })
        }

        /// Calls a method on the object with only positional arguments.
        ///
        /// This is equivalent to the Python expression `self.name(*args)`.
        pub fn call_method1(
            &self,
            py: Python,
            name: &str,
            args: impl IntoPy<Py<PyTuple>>,
        ) -> PyResult<PyObject> {
            self.call_method(py, name, args, None)
        }

        /// Calls a method on the object with no arguments.
        ///
        /// This is equivalent to the Python expression `self.name()`.
        pub fn call_method0(&self, py: Python, name: &str) -> PyResult<PyObject> {
            cfg_if::cfg_if! {
                if #[cfg(all(Py_3_9, not(Py_LIMITED_API)))] {
                    // Optimized path on python 3.9+
                    unsafe {
                        let name = name.into_py(py);
                        PyObject::from_owned_ptr_or_err(py, ffi::PyObject_CallMethodNoArgs(self.as_ptr(), name.as_ptr()))
                    }
                } else {
                    self.call_method(py, name, (), None)
                }
            }
        }

        /// Create a `Py<T>` instance by taking ownership of the given FFI pointer.
        ///
        /// # Safety
        /// `ptr` must be a pointer to a Python object of type T.
        ///
        /// Callers must own the object referred to by `ptr`, as this function
        /// implicitly takes ownership of that object.
        ///
        /// # Panics
        /// Panics if `ptr` is null.
        #[inline]
        pub unsafe fn from_owned_ptr(py: Python, ptr: *mut ffi::PyObject) -> Py<T> {
            match NonNull::new(ptr) {
                Some(nonnull_ptr) => Py(nonnull_ptr, PhantomData),
                None => crate::err::panic_after_error(py),
            }
        }

        /// Deprecated alias for [`from_owned_ptr`](#method.from_owned_ptr).
        ///
        /// # Safety
        /// `ptr` must be a pointer to a Python object of type T.
        ///
        /// Callers must own the object referred to by `ptr`, as this function
        /// implicitly takes ownership of that object.
        #[inline]
        #[deprecated = "this is a deprecated alias for Py::from_owned_ptr"]
        pub unsafe fn from_owned_ptr_or_panic(py: Python, ptr: *mut ffi::PyObject) -> Py<T> {
            Py::from_owned_ptr(py, ptr)
        }

        /// Create a `Py<T>` instance by taking ownership of the given FFI pointer.
        ///
        /// If `ptr` is null then the current Python exception is fetched as a `PyErr`.
        ///
        /// # Safety
        /// If non-null, `ptr` must be a pointer to a Python object of type T.
        #[inline]
        pub unsafe fn from_owned_ptr_or_err(py: Python, ptr: *mut ffi::PyObject) -> PyResult<Py<T>> {
            match NonNull::new(ptr) {
                Some(nonnull_ptr) => Ok(Py(nonnull_ptr, PhantomData)),
                None => Err(PyErr::fetch(py)),
            }
        }

        /// Create a `Py<T>` instance by taking ownership of the given FFI pointer.
        ///
        /// If `ptr` is null then `None` is returned.
        ///
        /// # Safety
        /// If non-null, `ptr` must be a pointer to a Python object of type T.
        #[inline]
        pub unsafe fn from_owned_ptr_or_opt(_py: Python, ptr: *mut ffi::PyObject) -> Option<Self> {
            match NonNull::new(ptr) {
                Some(nonnull_ptr) => Some(Py(nonnull_ptr, PhantomData)),
                None => None,
            }
        }

        /// Create a `Py<T>` instance by creating a new reference from the given FFI pointer.
        ///
        /// # Safety
        /// `ptr` must be a pointer to a Python object of type T.
        ///
        /// # Panics
        /// Panics if `ptr` is null.
        #[inline]
        pub unsafe fn from_borrowed_ptr(py: Python, ptr: *mut ffi::PyObject) -> Py<T> {
            match Self::from_borrowed_ptr_or_opt(py, ptr) {
                Some(slf) => slf,
                None => crate::err::panic_after_error(py),
            }
        }

        /// Create a `Py<T>` instance by creating a new reference from the given FFI pointer.
        ///
        /// If `ptr` is null then the current Python exception is fetched as a `PyErr`.
        ///
        /// # Safety
        /// `ptr` must be a pointer to a Python object of type T.
        #[inline]
        pub unsafe fn from_borrowed_ptr_or_err(py: Python, ptr: *mut ffi::PyObject) -> PyResult<Self> {
            Self::from_borrowed_ptr_or_opt(py, ptr).ok_or_else(|| PyErr::fetch(py))
        }

        /// Create a `Py<T>` instance by creating a new reference from the given FFI pointer.
        ///
        /// If `ptr` is null then `None` is returned.
        ///
        /// # Safety
        /// `ptr` must be a pointer to a Python object of type T.
        #[inline]
        pub unsafe fn from_borrowed_ptr_or_opt(_py: Python, ptr: *mut ffi::PyObject) -> Option<Self> {
            NonNull::new(ptr).map(|nonnull_ptr| {
                ffi::Py_INCREF(ptr);
                Py(nonnull_ptr, PhantomData)
            })
        }

        /// For internal conversions.
        ///
        /// # Safety
        /// `ptr` must point to a Python object of type T.
        #[inline]
        unsafe fn from_non_null(ptr: NonNull<ffi::PyObject>) -> Self {
            Self(ptr, PhantomData)
        }

        /// Returns the inner pointer without decreasing the refcount.
        #[inline]
        fn into_non_null(self) -> NonNull<ffi::PyObject> {
            let pointer = self.0;
            mem::forget(self);
            pointer
        }
    }

    impl<T> ToPyObject for Py<T> {
        /// Converts `Py` instance -> PyObject.
        fn to_object(&self, py: Python) -> PyObject {
            unsafe { PyObject::from_borrowed_ptr(py, self.as_ptr()) }
        }
    }

    impl<T> IntoPy<PyObject> for Py<T> {
        /// Converts a `Py` instance to `PyObject`.
        /// Consumes `self` without calling `Py_DECREF()`.
        #[inline]
        fn into_py(self, _py: Python) -> PyObject {
            unsafe { PyObject::from_non_null(self.into_non_null()) }
        }
    }

    impl<T> AsPyPointer for Py<T> {
        /// Gets the underlying FFI pointer, returns a borrowed pointer.
        #[inline]
        fn as_ptr(&self) -> *mut ffi::PyObject {
            self.0.as_ptr()
        }
    }

    impl<T> IntoPyPointer for Py<T> {
        /// Gets the underlying FFI pointer, returns a owned pointer.
        #[inline]
        #[must_use]
        fn into_ptr(self) -> *mut ffi::PyObject {
            self.into_non_null().as_ptr()
        }
    }

    impl<T> std::convert::From<&'_ T> for PyObject
    where
        T: AsPyPointer + PyNativeType,
    {
        fn from(obj: &T) -> Self {
            unsafe { Py::from_borrowed_ptr(obj.py(), obj.as_ptr()) }
        }
    }

    impl<T> std::convert::From<Py<T>> for PyObject
    where
        T: AsRef<PyAny>,
    {
        #[inline]
        fn from(other: Py<T>) -> Self {
            unsafe { Self::from_non_null(other.into_non_null()) }
        }
    }

    // `&PyCell<T>` can be converted to `Py<T>`
    impl<'a, T> std::convert::From<&PyCell<T>> for Py<T>
    where
        T: PyClass,
    {
        fn from(cell: &PyCell<T>) -> Self {
            unsafe { Py::from_borrowed_ptr(cell.py(), cell.as_ptr()) }
        }
    }

    impl<'a, T> std::convert::From<PyRef<'a, T>> for Py<T>
    where
        T: PyClass,
    {
        fn from(pyref: PyRef<'a, T>) -> Self {
            unsafe { Py::from_borrowed_ptr(pyref.py(), pyref.as_ptr()) }
        }
    }

    impl<'a, T> std::convert::From<PyRefMut<'a, T>> for Py<T>
    where
        T: PyClass,
    {
        fn from(pyref: PyRefMut<'a, T>) -> Self {
            unsafe { Py::from_borrowed_ptr(pyref.py(), pyref.as_ptr()) }
        }
    }

    impl<T> PartialEq for Py<T> {
        #[inline]
        fn eq(&self, o: &Py<T>) -> bool {
            self.0 == o.0
        }
    }

    impl<T> Clone for Py<T> {
        fn clone(&self) -> Self {
            unsafe {
                gil::register_incref(self.0);
            }
            Self(self.0, PhantomData)
        }
    }

    /// Dropping a `Py` instance decrements the reference count on the object by 1.
    impl<T> Drop for Py<T> {
        fn drop(&mut self) {
            unsafe {
                gil::register_decref(self.0);
            }
        }
    }

    impl<'a, T> FromPyObject<'a> for Py<T>
    where
        T: PyTypeInfo,
        &'a T::AsRefTarget: FromPyObject<'a>,
        T::AsRefTarget: 'a + AsPyPointer,
    {
        /// Extracts `Self` from the source `PyObject`.
        fn extract(ob: &'a PyAny) -> PyResult<Self> {
            unsafe {
                ob.extract::<&T::AsRefTarget>()
                    .map(|val| Py::from_borrowed_ptr(ob.py(), val.as_ptr()))
            }
        }
    }

    /// Py<T> can be used as an error when T is an Error.
    ///
    /// However for GIL lifetime reasons, cause() cannot be implemented for Py<T>.
    /// Use .as_ref() to get the GIL-scoped error if you need to inspect the cause.
    impl<T> std::error::Error for Py<T>
    where
        T: std::error::Error + PyTypeInfo,
        T::AsRefTarget: std::fmt::Display,
    {
    }

    impl<T> std::fmt::Display for Py<T>
    where
        T: PyTypeInfo,
        T::AsRefTarget: std::fmt::Display,
    {
        fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
            let gil = Python::acquire_gil();
            let py = gil.python();
            std::fmt::Display::fmt(self.as_ref(py), f)
        }
    }

    impl<T> std::fmt::Debug for Py<T> {
        fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
            f.debug_tuple("Py").field(&self.0.as_ptr()).finish()
        }
    }

    /// A commonly-used alias for `Py<PyAny>`.
    ///
    /// This is an owned reference a Python object without any type information. This value can also be
    /// safely sent between threads.
    ///
    /// See the documentation for [`Py`](struct.Py.html).
    pub type PyObject = Py<PyAny>;

    impl PyObject {
        /// Casts the PyObject to a concrete Python object type.
        ///
        /// This can cast only to native Python types, not types implemented in Rust. For a more
        /// flexible alternative, see [`Py::extract`](struct.Py.html#method.extract).
        pub fn cast_as<'p, D>(&'p self, py: Python<'p>) -> Result<&'p D, PyDowncastError>
        where
            D: PyTryFrom<'p>,
        {
            D::try_from(unsafe { py.from_borrowed_ptr::<PyAny>(self.as_ptr()) })
        }
    }

    #[cfg(test)]
    mod test {
        use super::{Py, PyObject};
        use crate::types::PyDict;
        use crate::{ffi, AsPyPointer, Python};

        #[test]
        fn test_call_for_non_existing_method() {
            let gil = Python::acquire_gil();
            let py = gil.python();
            let obj: PyObject = PyDict::new(py).into();
            assert!(obj.call_method0(py, "asdf").is_err());
            assert!(obj
                .call_method(py, "nonexistent_method", (1,), None)
                .is_err());
            assert!(obj.call_method0(py, "nonexistent_method").is_err());
            assert!(obj.call_method1(py, "nonexistent_method", (1,)).is_err());
        }

        #[test]
        fn py_from_dict() {
            let dict: Py<PyDict> = {
                let gil = Python::acquire_gil();
                let py = gil.python();
                let native = PyDict::new(py);
                Py::from(native)
            };
            assert_eq!(unsafe { ffi::Py_REFCNT(dict.as_ptr()) }, 1);
        }

        #[test]
        fn pyobject_from_py() {
            Python::with_gil(|py| {
                let dict: Py<PyDict> = PyDict::new(py).into();
                let cnt = dict.get_refcnt(py);
                let p: PyObject = dict.into();
                assert_eq!(p.get_refcnt(py), cnt);
            });
        }
    }