split vm.import and vm.import_from (#5212)

examples/call_between_rust_and_python.rs

@@ -17,7 +17,7 @@ pub fn main() {
         vm.insert_sys_path(vm.new_pyobj("examples"))
             .expect("add path");
 
-        let module = vm.import("call_between_rust_and_python", None, 0).unwrap();
+        let module = vm.import("call_between_rust_and_python", 0).unwrap();
         let init_fn = module.get_attr("python_callback", vm).unwrap();
         init_fn.call((), vm).unwrap();
 

examples/package_embed.rs

@@ -7,7 +7,7 @@ fn py_main(interp: &Interpreter) -> vm::PyResult<PyStrRef> {
         // Add local library path
         vm.insert_sys_path(vm.new_pyobj("examples"))
             .expect("add examples to sys.path failed");
-        let module = vm.import("package_embed", None, 0)?;
+        let module = vm.import("package_embed", 0)?;
         let name_func = module.get_attr("context", vm)?;
         let result = name_func.call((), vm)?;
         let result: PyStrRef = result.get_attr("name", vm)?.try_into_value(vm)?;

src/lib.rs

@@ -175,7 +175,7 @@ fn run_rustpython(vm: &VirtualMachine, run_mode: RunMode, quiet: bool) -> PyResu
         )?;
     }
 
-    let site_result = vm.import("site", None, 0);
+    let site_result = vm.import("site", 0);
     if site_result.is_err() {
         warn!(
             "Failed to import site, consider adding the Lib directory to your RUSTPYTHONPATH \

stdlib/src/array.rs

@@ -10,7 +10,7 @@ pub(crate) fn make_module(vm: &VirtualMachine) -> PyRef<PyModule> {
         .expect("Expect array has array type.");
 
     let collections_abc = vm
-        .import("collections.abc", None, 0)
+        .import("collections.abc", 0)
         .expect("Expect collections exist.");
     let abc = collections_abc
         .get_attr("abc", vm)
@@ -1165,7 +1165,7 @@ mod array {
             let bytes = vm.ctx.new_bytes(array.get_bytes().to_vec());
             let code = MachineFormatCode::from_typecode(array.typecode()).unwrap();
             let code = PyInt::from(u8::from(code)).into_pyobject(vm);
-            let module = vm.import("array", None, 0)?;
+            let module = vm.import("array", 0)?;
             let func = module.get_attr("_array_reconstructor", vm)?;
             Ok((
                 func,

stdlib/src/sqlite.rs

@@ -1301,7 +1301,7 @@ mod _sqlite {
 
         #[pymethod]
         fn iterdump(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyResult {
-            let module = vm.import("sqlite3.dump", None, 0)?;
+            let module = vm.import("sqlite3.dump", 0)?;
             let func = module.get_attr("_iterdump", vm)?;
             func.call((zelf,), vm)
         }

vm/src/builtins/module.rs

@@ -202,7 +202,7 @@ impl GetAttr for PyModule {
 impl Representable for PyModule {
     #[inline]
     fn repr(zelf: &Py<Self>, vm: &VirtualMachine) -> PyResult<PyStrRef> {
-        let importlib = vm.import("_frozen_importlib", None, 0)?;
+        let importlib = vm.import("_frozen_importlib", 0)?;
         let module_repr = importlib.get_attr("_module_repr", vm)?;
         let repr = module_repr.call((zelf.to_owned(),), vm)?;
         repr.downcast()

vm/src/builtins/object.rs

@@ -366,11 +366,11 @@ pub fn init(ctx: &Context) {
 
 fn common_reduce(obj: PyObjectRef, proto: usize, vm: &VirtualMachine) -> PyResult {
     if proto >= 2 {
-        let reducelib = vm.import("__reducelib", None, 0)?;
+        let reducelib = vm.import("__reducelib", 0)?;
         let reduce_2 = reducelib.get_attr("reduce_2", vm)?;
         reduce_2.call((obj,), vm)
     } else {
-        let copyreg = vm.import("copyreg", None, 0)?;
+        let copyreg = vm.import("copyreg", 0)?;
         let reduce_ex = copyreg.get_attr("_reduce_ex", vm)?;
         reduce_ex.call((obj, proto), vm)
     }

vm/src/builtins/tuple.rs

@@ -510,6 +510,13 @@ impl<T: TransmuteFromObject> AsRef<[T]> for PyTupleTyped<T> {
 }
 
 impl<T: TransmuteFromObject> PyTupleTyped<T> {
+    pub fn empty(vm: &VirtualMachine) -> Self {
+        Self {
+            tuple: vm.ctx.empty_tuple.clone(),
+            _marker: PhantomData,
+        }
+    }
+
     #[inline]
     pub fn as_slice(&self) -> &[T] {
         unsafe { &*(self.tuple.as_slice() as *const [PyObjectRef] as *const [T]) }

vm/src/frame.rs

@@ -1136,12 +1136,13 @@ impl ExecutingFrame<'_> {
     }
 
     #[cfg_attr(feature = "flame-it", flame("Frame"))]
-    fn import(&mut self, vm: &VirtualMachine, module: Option<&Py<PyStr>>) -> PyResult<()> {
-        let module = module.unwrap_or(vm.ctx.empty_str);
-        let from_list = <Option<PyTupleTyped<PyStrRef>>>::try_from_object(vm, self.pop_value())?;
+    fn import(&mut self, vm: &VirtualMachine, module_name: Option<&Py<PyStr>>) -> PyResult<()> {
+        let module_name = module_name.unwrap_or(vm.ctx.empty_str);
+        let from_list = <Option<PyTupleTyped<PyStrRef>>>::try_from_object(vm, self.pop_value())?
+            .unwrap_or_else(|| PyTupleTyped::empty(vm));
         let level = usize::try_from_object(vm, self.pop_value())?;
 
-        let module = vm.import(module, from_list, level)?;
+        let module = vm.import_from(module_name, from_list, level)?;
 
         self.push_value(module);
         Ok(())

vm/src/import.rs

@@ -46,7 +46,7 @@ pub(crate) fn init_importlib_package(vm: &VirtualMachine, importlib: PyObjectRef
         let install_external = importlib.get_attr("_install_external_importers", vm)?;
         install_external.call((), vm)?;
         // Set pyc magic number to commit hash. Should be changed when bytecode will be more stable.
-        let importlib_external = vm.import("_frozen_importlib_external", None, 0)?;
+        let importlib_external = vm.import("_frozen_importlib_external", 0)?;
         let mut magic = get_git_revision().into_bytes();
         magic.truncate(4);
         if magic.len() != 4 {
@@ -55,7 +55,7 @@ pub(crate) fn init_importlib_package(vm: &VirtualMachine, importlib: PyObjectRef
         let magic: PyObjectRef = vm.ctx.new_bytes(magic).into();
         importlib_external.set_attr("MAGIC_NUMBER", magic, vm)?;
         let zipimport_res = (|| -> PyResult<()> {
-            let zipimport = vm.import("zipimport", None, 0)?;
+            let zipimport = vm.import("zipimport", 0)?;
             let zipimporter = zipimport.get_attr("zipimporter", vm)?;
             let path_hooks = vm.sys_module.get_attr("path_hooks", vm)?;
             let path_hooks = list::PyListRef::try_from_object(vm, path_hooks)?;

vm/src/stdlib/codecs.rs

@@ -355,7 +355,7 @@ mod _codecs {
         vm: &VirtualMachine,
     ) -> PyResult {
         let f = cell.get_or_try_init(|| {
-            let module = vm.import("_pycodecs", None, 0)?;
+            let module = vm.import("_pycodecs", 0)?;
             module.get_attr(name, vm)
         })?;
         f.call(args, vm)

vm/src/stdlib/io.rs

@@ -2204,7 +2204,7 @@ mod _io {
                 Some(enc) if enc.as_str() != "locale" => enc,
                 _ => {
                     // None without utf8_mode or "locale" encoding
-                    vm.import("locale", None, 0)?
+                    vm.import("locale", 0)?
                         .get_attr("getencoding", vm)?
                         .call((), vm)?
                         .try_into_value(vm)?

vm/src/stdlib/operator.rs

@@ -538,7 +538,7 @@ mod _operator {
             } else {
                 // If we have kwargs, create a partial function that contains them and pass back that
                 // along with the args.
-                let partial = vm.import("functools", None, 0)?.get_attr("partial", vm)?;
+                let partial = vm.import("functools", 0)?.get_attr("partial", vm)?;
                 let args = FuncArgs::new(
                     vec![zelf.class().to_owned().into(), zelf.name.clone().into()],
                     KwArgs::new(zelf.args.kwargs.clone()),

vm/src/stdlib/sre.rs

@@ -118,7 +118,7 @@ mod _sre {
             repl: PyObjectRef,
             vm: &VirtualMachine,
         ) -> PyResult<PyRef<Self>> {
-            let re = vm.import("re", None, 0)?;
+            let re = vm.import("re", 0)?;
             let func = re.get_attr("_compile_template", vm)?;
             let result = func.call((pattern, repl.clone()), vm)?;
             result
@@ -680,7 +680,7 @@ mod _sre {
 
         #[pymethod]
         fn expand(zelf: PyRef<Match>, template: PyStrRef, vm: &VirtualMachine) -> PyResult {
-            let re = vm.import("re", None, 0)?;
+            let re = vm.import("re", 0)?;
             let func = re.get_attr("_expand", vm)?;
             func.call((zelf.pattern.clone(), zelf, template), vm)
         }

vm/src/stdlib/sys.rs

@@ -378,7 +378,7 @@ mod sys {
             (&env_var[..(env_var.len() - last.len() - 1)], last)
         };
 
-        let module = match vm.import(&vm.ctx.new_str(module_path), None, 0) {
+        let module = match vm.import(&vm.ctx.new_str(module_path), 0) {
             Ok(module) => module,
             Err(_) => {
                 return print_unimportable_module_warn();
@@ -560,7 +560,7 @@ mod sys {
         }
 
         // TODO: print received unraisable.exc_traceback
-        let tb_module = vm.import("traceback", None, 0)?;
+        let tb_module = vm.import("traceback", 0)?;
         let print_stack = tb_module.get_attr("print_stack", vm)?;
         print_stack.call((), vm)?;
 

vm/src/stdlib/warnings.rs

@@ -9,7 +9,7 @@ pub fn warn(
     vm: &VirtualMachine,
 ) -> PyResult<()> {
     // TODO: use rust warnings module
-    if let Ok(module) = vm.import("warnings", None, 0) {
+    if let Ok(module) = vm.import("warnings", 0) {
         if let Ok(func) = module.get_attr("warn", vm) {
             let _ = func.call((message, category.to_owned(), stack_level), vm);
         }

vm/src/vm/compile.rs

@@ -29,7 +29,7 @@ impl VirtualMachine {
     pub fn run_script(&self, scope: Scope, path: &str) -> PyResult<()> {
         if get_importer(path, self)?.is_some() {
             self.insert_sys_path(self.new_pyobj(path))?;
-            let runpy = self.import("runpy", None, 0)?;
+            let runpy = self.import("runpy", 0)?;
             let run_module_as_main = runpy.get_attr("_run_module_as_main", self)?;
             run_module_as_main.call((identifier!(self, __main__).to_owned(), false), self)?;
             return Ok(());

vm/src/vm/mod.rs

@@ -222,7 +222,7 @@ impl VirtualMachine {
     /// init_importlib must be called before this call
     #[cfg(feature = "encodings")]
     fn import_encodings(&mut self) -> PyResult<()> {
-        self.import("encodings", None, 0).map_err(|import_err| {
+        self.import("encodings", 0).map_err(|import_err| {
             let rustpythonpath_env = std::env::var("RUSTPYTHONPATH").ok();
             let pythonpath_env = std::env::var("PYTHONPATH").ok();
             let env_set = rustpythonpath_env.as_ref().is_some() || pythonpath_env.as_ref().is_some();
@@ -396,7 +396,7 @@ impl VirtualMachine {
 
     #[cold]
     pub fn run_unraisable(&self, e: PyBaseExceptionRef, msg: Option<String>, object: PyObjectRef) {
-        let sys_module = self.import("sys", None, 0).unwrap();
+        let sys_module = self.import("sys", 0).unwrap();
         let unraisablehook = sys_module.get_attr("unraisablehook", self).unwrap();
 
         let exc_type = e.class().to_owned();
@@ -495,7 +495,7 @@ impl VirtualMachine {
 
     pub fn try_class(&self, module: &'static str, class: &'static str) -> PyResult<PyTypeRef> {
         let class = self
-            .import(module, None, 0)?
+            .import(module, 0)?
             .get_attr(class, self)?
             .downcast()
             .expect("not a class");
@@ -504,7 +504,7 @@ impl VirtualMachine {
 
     pub fn class(&self, module: &'static str, class: &'static str) -> PyTypeRef {
         let module = self
-            .import(module, None, 0)
+            .import(module, 0)
             .unwrap_or_else(|_| panic!("unable to import {module}"));
 
         let class = module
@@ -513,11 +513,24 @@ impl VirtualMachine {
         class.downcast().expect("not a class")
     }
 
+    /// Call Python __import__ function without from_list.
+    /// Roughly equivalent to `import module_name` or `import top.submodule`.
+    ///
+    /// See also [`import_from`] for more advanced import.
     #[inline]
-    pub fn import<'a>(
+    pub fn import<'a>(&self, module_name: impl AsPyStr<'a>, level: usize) -> PyResult {
+        let module_name = module_name.as_pystr(&self.ctx);
+        let from_list = PyTupleTyped::empty(self);
+        self.import_inner(module_name, from_list, level)
+    }
+
+    /// Call Python __import__ function caller with from_list.
+    /// Roughly equivalent to `from module_name import item1, item2` or `from top.submodule import item1, item2`
+    #[inline]
+    pub fn import_from<'a>(
         &self,
         module_name: impl AsPyStr<'a>,
-        from_list: Option<PyTupleTyped<PyStrRef>>,
+        from_list: PyTupleTyped<PyStrRef>,
         level: usize,
     ) -> PyResult {
         let module_name = module_name.as_pystr(&self.ctx);
@@ -527,14 +540,12 @@ impl VirtualMachine {
     fn import_inner(
         &self,
         module: &Py<PyStr>,
-        from_list: Option<PyTupleTyped<PyStrRef>>,
+        from_list: PyTupleTyped<PyStrRef>,
         level: usize,
     ) -> PyResult {
         // if the import inputs seem weird, e.g a package import or something, rather than just
         // a straight `import ident`
-        let weird = module.as_str().contains('.')
-            || level != 0
-            || from_list.as_ref().map_or(false, |x| !x.is_empty());
+        let weird = module.as_str().contains('.') || level != 0 || !from_list.is_empty();
 
         let cached_module = if weird {
             None
@@ -567,10 +578,7 @@ impl VirtualMachine {
                 } else {
                     (None, None)
                 };
-                let from_list = match from_list {
-                    Some(tup) => tup.to_pyobject(self),
-                    None => self.new_tuple(()).into(),
-                };
+                let from_list = from_list.to_pyobject(self);
                 import_func
                     .call((module.to_owned(), globals, locals, from_list, level), self)
                     .map_err(|exc| import::remove_importlib_frames(self, &exc))
@@ -859,7 +867,7 @@ impl VirtualMachine {
     }
 
     pub fn run_module(&self, module: &str) -> PyResult<()> {
-        let runpy = self.import("runpy", None, 0)?;
+        let runpy = self.import("runpy", 0)?;
         let run_module_as_main = runpy.get_attr("_run_module_as_main", self)?;
         run_module_as_main.call((module,), self)?;
         Ok(())

vm/src/warn.rs

@@ -62,7 +62,7 @@ fn get_warnings_attr(
             .finalizing
             .load(std::sync::atomic::Ordering::SeqCst)
     {
-        match vm.import("warnings", None, 0) {
+        match vm.import("warnings", 0) {
             Ok(module) => module,
             Err(_) => return Ok(None),
         }