How to execute 'dill.load' in Rust?

[k82cn]

I'm using following code to dump Python function into a file:

hello.py

@flame.service
def add(x: int, y: int) -> int:
    return x + y

flame.py

def service(fn):
    print(fn.__qualname__)

    # Connection 
    with open('service_code.pkl', 'wb') as file:
        dill.dump(fn, file)

    def service_future(*args, **kwargs):
        with open('service_input.pkl', 'wb') as file:
            dill.dump((args, kwargs), file)

        for k, v in kwargs.items():
            ret = fn(*args, **kwargs)

        return ret

    return service_future

After dump the python func and objects, I'd like to execute them in Rust by PyO3 as follow:

use std::fs::File;
use std::io::prelude::*;

use pyo3::prelude::*;
use pyo3::types::PyTuple;

fn main() -> PyResult<()> {
    Python::with_gil(|py| {
        let mut f = File::open("service_code.pkl")?;
        let mut buffer = Vec::new();

        // read the whole file
        f.read_to_end(&mut buffer)?;

        let dill = py.import("dill")?;
        let load_fn = dill.getattr("loads")?;
        let args = PyTuple::new(py, &[buffer]);

        let _task_fn = load_fn.call(args, None)?;

        Ok(())
    })
}

But I got the following error during execution:

$ ./target/debug/python-shim 
Error: PyErr { type: <class 'TypeError'>, value: TypeError("a bytes-like object is required, not 'list'"), traceback: Some(<traceback object at 0x7f5ef5b3c480>) }

So I'd like to know to pass through a bytes-like object as args for dill.load?

xref: https://github.com/k82cn/rust-learning/tree/main/pyo3

[k82cn]

It's handled by introducing PyBytes as follow:

  let task_code = PyBytes::new(py, &buffer);
  let task_code = PyTuple::new(py, &[task_code]);