PyO3-File

This is a small utility library to facilitate working with python file-like objects with rust.

Example

An example use case for this is when a file is opened in python, and needs to be passed to a rust library.

We could support both by introspecting the PyObject, and pick the correct behavior.

We would like this to work: ```python from pathorfilelike import acceptspathorfile_like

def main(): # should open some_file.txt. acceptspathorfilelike("./some_file.txt")

# should read from the python handle.
f = open('./some_file.txt')
accepts_path_or_file_like(f)

```

We could use pyo3_file to extend an existing a pyo3 module.

```rust use pyo3_file::PyFileLikeObject; use pyo3::types::PyString;

use pyo3::prelude::*; use pyo3::wrap_pyfunction; use std::io::Read; use std::fs::File;

/// Represents either a path File or a file-like object FileLike

[derive(Debug)]

enum FileOrFileLike { File(String), FileLike(PyFileLikeObject), }

impl FileOrFileLike { pub fn frompyobject(pathorfilelike: PyObject) -> PyResult { let gil = Python::acquire_gil(); let py = gil.python();

    // is a path
    if let Ok(string_ref) = path_or_file_like.cast_as::<PyString>(py) {
        return Ok(FileOrFileLike::File(
            string_ref.to_string_lossy().to_string(),
        ));
    }

    // is a file-like
    match PyFileLikeObject::with_requirements(path_or_file_like, true, false, true) {
        Ok(f) => Ok(FileOrFileLike::FileLike(f)),
        Err(e) => Err(e)
    }
}

}

[pyfunction]

/// Opens a file or file-like, and reads it to string. fn acceptspathorfilelike( pathorfilelike: PyObject, ) -> PyResult> { let gil = Python::acquiregil(); let py = gil.python();

match FileOrFileLike::from_pyobject(path_or_file_like) {
    Ok(f) => match f {
        FileOrFileLike::File(s) => {
            println!("It's a file! - path {}", s);
            let mut f = File::open(s)?;
            let mut string = String::new();

            let read = f.read_to_string(&mut string);
            Ok(PyString::new(py, &string))
        }
        FileOrFileLike::FileLike(mut f) => {
            println!("Its a file-like object");
            let mut string = String::new();

            let read = f.read_to_string(&mut string);
            Ok(PyString::new(py, &string))
        }
    },
    Err(e) => Err(e),
}

}

[pymodule]

fn pathorfilelike(py: Python, m: &PyModule) -> PyResult<()> { m.addwrapped(wrappyfunction!(acceptspathorfilelike))?;

Ok(())

}

fn main() {}

```