Recommended way for creating a wrapper class in Rust

Hey, I want to write some Rust algorithms that operate on a numpy array that was created in python. E.g.:

arr = np.ones((1000, 768))
dataset = MyRustWrapper(arr) # Rust wrapper class
idx = 199
dataset.get_nearest_neighbor(idx)

Because the array is quite big, I would like to avoid copying the data and just wrap a Array2<f32> that is passed from python.
But how can I take a Array2<f32> and pass it into the fn new of the Rust struct? I only managed to get this working, by extenting the lifetime of new<'py>(arr: PyReadonlyArray2<'py, f32>) -> PyResult<Self> to 'static with unsafe which is likely incorrect:

struct MyRustWrapper(PyReadonlyArray2<'static, f32>)
impl MyRustWrapper {
    fn new<'py>(arr: PyReadonlyArray2<'py, f32>) -> PyResult<Self>{
         Self(unsafe { std::mem::transmute(arr) })
    }
}

Also on a sidenote, how can I make sure that the rows of the numpy array are all f32 and are laid out as slices in memory?

Thanks in advance for any help.

Start by reading the PyReadonlyArray2 APIs and the Rust wrapper constructor shown in the issue, focusing on ownership and lifetime requirements. Done should be a documented safe approach for wrapping the Python NumPy array without copying, including how to handle f32 dtype and row layout.