RustPython · markusmoenig · Aug 2, 2025 · Aug 4, 2025 · Aug 4, 2025 · Aug 5, 2025
diff --git a/examples/module_injection.rs b/examples/module_injection.rs
@@ -0,0 +1,47 @@
+use rustpython::vm::*;
+use rustpython_vm::builtins::PyModule;
+
+/// A global fn called from Python which extracts the id from the injected module and returns / prints it to the console.
+/// This is useful in a multi-threaded environment where you may have several threads sharing global functions. The
+/// id would allow a local context for each thread, for example by using a global Arc<Mutex<Hashmap>>.
+fn get_id(vm: &vm::VirtualMachine) -> PyResult<i32> {
+    let module = vm.import("__id_module", 0)?;
+    let obj = module.get_attr("__id", vm)?;
+    let id = obj.try_to_value::<i32>(vm)?;
+
+    println!("The id is {}", id);
+
+    Ok(id)
+}
+
+fn main() -> PyResult<()> {
+    vm::Interpreter::without_stdlib(Default::default()).enter(|vm| {
+        let scope = vm.new_scope_with_builtins();
+
+        // Register the global function
+        let _ = scope
+            .globals
+            .set_item("get_id", vm.new_function("get_id", get_id).into(), vm);
+
+        // Create a module and set an id
+        let module = PyModule::new().into_ref(&vm.ctx);
+        module
+            .as_object()
+            .set_attr("__id", vm.new_pyobj(42_i32), vm)?;
+
+        // Register the module
+        let sys = vm.import("sys", 0)?;
+        let modules = sys.get_attr("modules", vm)?;
+        modules.set_item("__id_module", module.into(), vm)?;
+
+        // Execute the code
+        let source = r#"get_id()"#;
+        let code_obj = vm
+            .compile(source, compiler::Mode::Exec, "<embedded>".to_owned())
+            .map_err(|err| vm.new_syntax_error(&err, Some(source)))?;
+
+        vm.run_code_obj(code_obj, scope)?;
+
+        Ok(())
+    })
+}