initial_setup.md

Initial Setup

First rustpython_vm needs to be imported. If rustpython is installed, it can be imported as a re-export:

use rustpython::vm;

if rustpython_vm is installed, it can be imported just like any other module.

use rustpython::vm;

fn main() -> vm::PyResult<()> {
    vm::Interpreter::without_stdlib(Default::default()).enter(|vm| {
        let scope = vm.new_scope_with_builtins();
        let source = r#"print("Hello World!")"#;
        let code_obj = vm
            .compile(source, vm::compiler::Mode::Exec, "<embedded>".to_owned())
            .map_err(|err| vm.new_syntax_error(&err, Some(source)))?;

        vm.run_code_obj(code_obj, scope)?;

        Ok(())
    })
}

This will print Hello World! to the console.

Adding the standard library

If the stdlib feature is enabled, the standard library can be added to the interpreter by calling add_native_modules with the result of rustpython_stdlib::get_module_inits().

use rustpython::vm as vm;
use std::process::ExitCode;
use vm::{Interpreter, builtins::PyStrRef};

fn py_main(interp: &Interpreter) -> vm::PyResult<PyStrRef> {
    interp.enter(|vm| {
        let scope = vm.new_scope_with_builtins();
        let source = r#"print("Hello World!")"#;
        let code_obj = vm
            .compile(source, vm::compiler::Mode::Exec, "<embedded>".to_owned())
            .map_err(|err| vm.new_syntax_error(&err, Some(source)))?;

        vm.run_code_obj(code_obj, scope)?;
    })
}

fn main() -> ExitCode {
    // Add standard library path
    let mut settings = vm::Settings::default();
    settings.path_list.push("Lib".to_owned());
    let interp = vm::Interpreter::with_init(settings, |vm| {
        vm.add_native_modules(rustpython_stdlib::get_module_inits());
    });
    let result = py_main(&interp);
    let result = result.map(|result| {
        println!("name: {result}");
    });
    ExitCode::from(interp.run(|_vm| result))
}

to import a module, the following code can be used:

// Add local library path
vm.insert_sys_path(vm.new_pyobj("<module_path>"))
    .expect("add examples to sys.path failed");
let module = vm.import("<module_name>", 0)?;