diff --git a/callable.mbt b/callable.mbt
index 2d7157b..622846f 100644
--- a/callable.mbt
+++ b/callable.mbt
@@ -35,6 +35,11 @@ fn PyCallable::create_by_ref_unchecked(
   PyCallable::{ obj: PyObject::create(obj) }
 }
 
+///|
+test {
+  ignore(PyCallable::create_by_ref_unchecked)
+}
+
 ///|
 pub fn PyCallable::dump(self : PyCallable) -> Unit {
   self.obj.dump()
diff --git a/cpython/context.mbt b/cpython/context.mbt
index bed934d..5cc7b3c 100644
--- a/cpython/context.mbt
+++ b/cpython/context.mbt
@@ -23,20 +23,20 @@ pub extern "C" fn py_context_var_new(
 
 ///|
 pub extern "C" fn py_context_var_get(
-  var : PyObjectRef,
+  pyvar : PyObjectRef,
   default_value : PyObjectRef,
   value : ArrayPyObjectRef
 ) -> Int = "PyContextVar_Get"
 
 ///|
 pub extern "C" fn py_context_var_set(
-  var : PyObjectRef,
+  pyvar : PyObjectRef,
   value : PyObjectRef
 ) -> PyObjectRef = "PyContextVar_Set"
 
 ///|
 pub extern "C" fn py_context_var_reset(
-  var : PyObjectRef,
+  pyvar : PyObjectRef,
   token : PyObjectRef
 ) -> Int = "PyContextVar_Reset"
 
diff --git a/cpython/core.mbt b/cpython/core.mbt
index 6295f4d..b07538d 100644
--- a/cpython/core.mbt
+++ b/cpython/core.mbt
@@ -55,6 +55,12 @@ fn CStr::to_string_with_length(self : CStr, len : UInt) -> String {
   c_str_to_moonbit_str_with_length(self, len)
 }
 
+///|
+test {
+  ignore(CStr::to_string_with_length)
+  ignore(CWStr::from)
+}
+
 ///|
 fn CWStr::from(s : String) -> CWStr {
   moonbit_str_to_cw_str(s)
@@ -70,6 +76,12 @@ fn CWStr::to_string_with_length(self : CWStr, len : UInt) -> String {
   cw_str_to_moonbit_str_with_length(self, len)
 }
 
+///|
+test {
+  ignore(CWStr::to_string_with_length)
+  ignore(CWStr::to_string)
+}
+
 ///|
 extern "C" fn py_object_is_null(obj : PyObjectRef) -> Int = "Moonbit_PyObjectRef_is_null"
 
diff --git a/float.mbt b/float.mbt
index 3bbec35..a23c0a3 100644
--- a/float.mbt
+++ b/float.mbt
@@ -29,6 +29,11 @@ fn PyFloat::create_by_ref_unchecked(obj : @cpython.PyObjectRef) -> PyFloat {
   PyFloat::{ obj: PyObject::create(obj) }
 }
 
+///|
+test {
+  ignore(PyFloat::create_by_ref_unchecked)
+}
+
 ///| Create a PyFloat from a Double value.
 ///
 /// ## Example
diff --git a/integer.mbt b/integer.mbt
index 704a8ba..79c8b99 100644
--- a/integer.mbt
+++ b/integer.mbt
@@ -32,6 +32,11 @@ fn PyInteger::create_by_ref_unchecked(obj : @cpython.PyObjectRef) -> PyInteger {
   PyInteger::{ obj: PyObject::create(obj) }
 }
 
+///|
+test {
+  ignore(PyInteger::create_by_ref_unchecked)
+}
+
 ///| Create a PyInteger from an integer.
 ///
 /// ## Example
diff --git a/list.mbt b/list.mbt
index bd57d60..b24bd49 100644
--- a/list.mbt
+++ b/list.mbt
@@ -251,7 +251,9 @@ pub fn[T : IsPyObject] PyList::op_set(
   idx : Int,
   item : T
 ) -> Unit {
-  self.set?(idx, item).unwrap()
+  self.set(idx, item) catch {
+    _ => panic()
+  }
 }
 
 ///| Let python interpreter print the list directly.
diff --git a/main/main.mbt b/main/main.mbt
index 9033e5a..265c8c8 100644
--- a/main/main.mbt
+++ b/main/main.mbt
@@ -17,7 +17,7 @@ fn main {
   args..set(0, py_nums)
 
   // It's equivalent to `cnt = Counter(nums)`
-  guard counter.invoke?(args~) is Ok(Some(cnt))
+  guard (try? counter.invoke(args~)) is Ok(Some(cnt))
   guard cnt is PyDict(cnt)
 
   // `print(cnt)`
diff --git a/module.mbt b/module.mbt
index f1165ae..ab67540 100644
--- a/module.mbt
+++ b/module.mbt
@@ -35,6 +35,10 @@ fn PyModule::create_by_ref_unchecked(
   PyModule::{ obj: PyObject::create(obj_ref), name: None, attrs: Map::new() }
 }
 
+///|
+test {
+  ignore(PyModule::create_by_ref_unchecked)
+}
 // REVIEW: what if user call pyimport twice or more?
 
 ///| Import a python module
diff --git a/str.mbt b/str.mbt
index c735c91..a5c19b0 100644
--- a/str.mbt
+++ b/str.mbt
@@ -35,6 +35,11 @@ fn PyString::create_by_ref_unchecked(
   PyString::{ obj: PyObject::create(obj_ref) }
 }
 
+///|
+test {
+  ignore(PyString::create_by_ref_unchecked)
+}
+
 ///| Create a PyString from a string
 ///
 /// ## Example
diff --git a/test/object_test.mbt b/test/object_test.mbt
index 2d09691..912be8f 100644
--- a/test/object_test.mbt
+++ b/test/object_test.mbt
@@ -123,6 +123,6 @@ test "PyDict Test" {
   inspect(dict, content="{1: 1, 2: 4, 3: 9}")
   let list = PyList::new()
   list..append(PyInteger::from(3))..append(PyInteger::from(2))
-  let e = dict.setByObj?(list, PyInteger::from(42))
+  let e = try? dict.setByObj(list, PyInteger::from(42))
   inspect(e, content="Err(KeyIsUnHashableError)")
 }
diff --git a/time/lib.mbt b/time/lib.mbt
index 84cd714..e3966dc 100644
--- a/time/lib.mbt
+++ b/time/lib.mbt
@@ -25,9 +25,8 @@ let singleton : () -> TimeModule = get_lib()
 ///|
 fn get_lib() -> () -> TimeModule {
   @python.init_py()
-  let lib = match new?() {
-    Ok(lib) => lib
-    Err(e) => {
+  let lib = new() catch {
+    e => {
       println(e)
       panic()
     }
@@ -41,7 +40,7 @@ pub fn sleep(seconds : Double) -> Unit {
   guard lib.time.get_attr("sleep") is Some(PyCallable(f))
   let args = PyTuple::new(1)
   args..set(0, PyFloat::from(seconds))
-  let _ = f.invoke?(args~)
+  let _ = try? f.invoke(args~)
   ()
 }
 
@@ -54,7 +53,7 @@ pub fn time() -> Double {
     println("Error: Could not get time.time function") // Placeholder error value
     return 0.0
   }
-  guard f.invoke?().unwrap() is Some(PyFloat(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyFloat(t)) else {
     println("Error: time.time did not return a float") // Placeholder error value
     return 0.0
   }
@@ -69,7 +68,7 @@ pub fn time_ns() -> Int64 {
     println("Error: Could not get time.time_ns function") // Placeholder error value
     return 0L
   }
-  guard f.invoke?().unwrap() is Some(PyInteger(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyInteger(t)) else {
     println("Error: time.time_ns did not return an integer") // Placeholder error value
     return 0L
   }
@@ -84,7 +83,7 @@ pub fn monotonic() -> Double {
     println("Error: Could not get time.monotonic function")
     return 0.0
   }
-  guard f.invoke?().unwrap() is Some(PyFloat(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyFloat(t)) else {
     println("Error: time.monotonic did not return a float")
     return 0.0
   }
@@ -99,7 +98,7 @@ pub fn monotonic_ns() -> Int64 {
     println("Error: Could not get time.monotonic_ns function")
     return 0L
   }
-  guard f.invoke?().unwrap() is Some(PyInteger(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyInteger(t)) else {
     println("Error: time.monotonic_ns did not return an integer")
     return 0L
   }
@@ -114,7 +113,7 @@ pub fn perf_counter() -> Double {
     println("Error: Could not get time.perf_counter function")
     return 0.0
   }
-  guard f.invoke?().unwrap() is Some(PyFloat(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyFloat(t)) else {
     println("Error: time.perf_counter did not return a float")
     return 0.0
   }
@@ -129,7 +128,7 @@ pub fn perf_counter_ns() -> Int64 {
     println("Error: Could not get time.perf_counter_ns function")
     return 0L
   }
-  guard f.invoke?().unwrap() is Some(PyInteger(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyInteger(t)) else {
     println("Error: time.perf_counter_ns did not return an integer")
     return 0L
   }
@@ -144,7 +143,7 @@ pub fn process_time() -> Double {
     println("Error: Could not get time.process_time function")
     return 0.0
   }
-  guard f.invoke?().unwrap() is Some(PyFloat(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyFloat(t)) else {
     println("Error: time.process_time did not return a float")
     return 0.0
   }
@@ -159,7 +158,7 @@ pub fn process_time_ns() -> Int64 {
     println("Error: Could not get time.process_time_ns function")
     return 0L
   }
-  guard f.invoke?().unwrap() is Some(PyInteger(t)) else {
+  guard (try? f.invoke()).unwrap() is Some(PyInteger(t)) else {
     println("Error: time.process_time_ns did not return an integer")
     return 0L
   }
@@ -179,9 +178,9 @@ pub fn ctime(secs_option : Double?) -> String {
     Some(secs) => {
       let args = PyTuple::new(1)
       args..set(0, PyFloat::from(secs))
-      f.invoke?(args~).unwrap()
+      (try? f.invoke(args~)).unwrap()
     }
-    None => f.invoke?().unwrap() // Call without arguments
+    None => (try? f.invoke()).unwrap() // Call without arguments
   }
   guard result is Some(PyString(s)) else {
     println("Error: time.ctime did not return a string") // Placeholder error value
diff --git a/tkinter/tkinter.mbt b/tkinter/tkinter.mbt
index 6e6f6f0..e573d1e 100644
--- a/tkinter/tkinter.mbt
+++ b/tkinter/tkinter.mbt
@@ -49,9 +49,8 @@ let singleton : () -> Tkinter = get_lib()
 ///|
 fn get_lib() -> () -> Tkinter {
   @python.init_py()
-  let lib = match new?() {
-    Ok(lib) => lib
-    Err(e) => {
+  let lib = new() catch {
+    e => {
       println(e)
       panic()
     }
@@ -63,7 +62,7 @@ fn get_lib() -> () -> Tkinter {
 pub fn Window::new() -> Window {
   let lib = singleton()
   guard lib.tkinter.get_attr("Tk") is Some(PyCallable(createWindow))
-  guard createWindow.invoke?().unwrap() is Some(PyClass(window))
+  guard (try? createWindow.invoke()).unwrap() is Some(PyClass(window))
   Window::{ window, }
 }
 
@@ -72,14 +71,14 @@ pub fn Window::set_title(self : Window, title : String) -> Unit {
   guard self.window.get_attr("title") is Some(PyCallable(setTitle))
   let args = PyTuple::new(1)
   args..set(0, PyString::from(title))
-  let _ = setTitle.invoke?(args~)
+  let _ = try? setTitle.invoke(args~)
 
 }
 
 ///|
 pub fn Window::mainloop(self : Window) -> Unit {
   guard self.window.get_attr("mainloop") is Some(PyCallable(mainloop))
-  let _ = mainloop.invoke?()
+  let _ = try? mainloop.invoke()
 
 }
 
@@ -91,13 +90,14 @@ pub fn Label::new(window : Window, text : String) -> Label {
   args..set(0, window.window)
   let kwargs = PyDict::new()
   kwargs..set("text", PyString::from(text))
-  guard createLabel.invoke?(args~, kwargs~).unwrap() is Some(PyClass(label))
+  guard (try? createLabel.invoke(args~, kwargs~)).unwrap()
+    is Some(PyClass(label))
   Label::{ label, }
 }
 
 ///|
 pub fn Label::pack(self : Label) -> Unit {
   guard self.label.get_attr("pack") is Some(PyCallable(pack))
-  let _ = pack.invoke?()
+  let _ = try? pack.invoke()
 
 }
diff --git a/tuple.mbt b/tuple.mbt
index 21dc263..8df9b31 100644
--- a/tuple.mbt
+++ b/tuple.mbt
@@ -54,6 +54,11 @@ fn PyTuple::create_by_ref_unchecked(obj_ref : @cpython.PyObjectRef) -> PyTuple {
   PyTuple::{ obj: PyObject::create(obj_ref) }
 }
 
+///|
+test {
+  ignore(PyTuple::create_by_ref_unchecked)
+}
+
 ///| Return the size of the tuple.
 ///
 /// ## Example:
diff --git a/turtle/lib.mbt b/turtle/lib.mbt
index c3d5483..4a1ec3f 100644
--- a/turtle/lib.mbt
+++ b/turtle/lib.mbt
@@ -34,9 +34,8 @@ let singleton : () -> Turtle = get_lib()
 ///|
 fn get_lib() -> () -> Turtle {
   @python.init_py()
-  let lib = match new?() {
-    Ok(lib) => lib
-    Err(e) => {
+  let lib = new() catch {
+    e => {
       println(e)
       panic()
     }
@@ -50,6 +49,6 @@ pub fn bgcolor(color : Color) -> Unit {
   guard lib.turtle.get_attr("bgcolor") is Some(PyCallable(bgcolor))
   let args = PyTuple::new(1)
   args..set(0, PyString::from(color.to_string()))
-  let _ = bgcolor.invoke?(args~)
+  let _ = try? bgcolor.invoke(args~)
   ()
 }
diff --git a/turtle/pen2.mbt b/turtle/pen2.mbt
index 42fe3c0..97bb003 100644
--- a/turtle/pen2.mbt
+++ b/turtle/pen2.mbt
@@ -28,7 +28,7 @@ fn Pen::get_method(self : Pen, name : String) -> PyCallable? {
 pub fn Pen::new() -> Pen {
   let lib = singleton()
   guard lib.turtle.get_attr("Pen") is Some(PyCallable(createPen))
-  guard createPen.invoke?().unwrap() is Some(PyClass(pen))
+  guard (try? createPen.invoke()).unwrap() is Some(PyClass(pen))
   Pen::{ pen, methods: Map::new() }
 }
 
@@ -39,7 +39,7 @@ pub fn Pen::home(self : Pen) -> Unit {
     println("Failed to get Pen::home method")
     panic()
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
   ()
 }
 
@@ -57,7 +57,7 @@ pub fn Pen::pensize(self : Pen, size : Double) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyFloat::from(size))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -68,7 +68,7 @@ pub fn Pen::xcor(self : Pen) -> Double {
     println("Failed to get Pen::xcor method") // Return a default value
     return 0.0
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyFloat(x))
   x.to_double()
 }
@@ -80,7 +80,7 @@ pub fn Pen::ycor(self : Pen) -> Double {
     println("Failed to get Pen::ycor method") // Return a default value
     return 0.0
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyFloat(y))
   y.to_double()
 }
@@ -92,7 +92,7 @@ pub fn Pen::position(self : Pen) -> (Double, Double) {
     println("Failed to get Pen::position method")
     return (0.0, 0.0) // Return a default value
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyTuple(tup)) else {
     println("Pen::position did not return a tuple")
     return (0.0, 0.0) // Return a default value
@@ -121,7 +121,7 @@ pub fn Pen::heading(self : Pen) -> Double {
     println("Failed to get Pen::heading method") // Return a default value
     return 0.0
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyFloat(h)) else {
     println("Pen::heading did not return a float") // Return a default value
     return 0.0
@@ -139,7 +139,7 @@ pub fn Pen::radians(self : Pen) -> Double {
     println("Failed to get Pen::radians method") // Return a default value
     return 0.0
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyFloat(r)) else {
     println("Pen::radians did not return a float") // Return a default value
     return 0.0
@@ -157,7 +157,7 @@ pub fn Pen::speed(self : Pen, speed : Speed) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, speed.to_pynum()) // speed.to_pynum() converts enum to PyInteger
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -171,7 +171,7 @@ pub fn Pen::pencolor(self : Pen, color : Color) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyString::from(color.to_string().to_lower())) // Ensure lowercase
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -189,7 +189,7 @@ pub fn Pen::width(self : Pen, width : Double) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyFloat::from(width))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -207,7 +207,7 @@ pub fn Pen::forward(self : Pen, distance : Double) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyFloat::from(distance))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -226,7 +226,7 @@ pub fn Pen::backward(self : Pen, distance : Double) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyFloat::from(distance))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -240,7 +240,7 @@ pub fn Pen::left(self : Pen, angle : Double) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyFloat::from(angle))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -254,7 +254,7 @@ pub fn Pen::right(self : Pen, angle : Double) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyFloat::from(angle))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -269,7 +269,7 @@ pub fn Pen::goto(self : Pen, x : Double, y : Double) -> Unit {
   }
   let args = PyTuple::new(2)
   args..set(0, PyFloat::from(x))..set(1, PyFloat::from(y))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -280,7 +280,7 @@ pub fn Pen::hide(self : Pen) -> Unit {
     println("Failed to get Pen::hideturtle method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -291,7 +291,7 @@ pub fn Pen::penup(self : Pen) -> Unit {
     println("Failed to get Pen::penup method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -302,7 +302,7 @@ pub fn Pen::pendown(self : Pen) -> Unit {
     println("Failed to get Pen::pendown method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -325,7 +325,7 @@ pub fn Pen::dot(self : Pen, size : Double, color : Color) -> Unit {
   ..set(1, PyString::from(color.to_string().to_lower())) // Ensure lowercase
   // The return value of dot is the turtle object itself, which we ignore and drop.
   // The original code had a 'guard func.invoke(args~) is Some(PyClass(r)) r.drop()', which is correct for ignoring the return value.
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
   // Simpler way to ignore return value
 }
 
@@ -336,7 +336,7 @@ pub fn Pen::clear(self : Pen) -> Unit {
     println("Failed to get Pen::clear method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -352,7 +352,7 @@ pub fn Pen::fillcolor(self : Pen, color : Color) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyString::from(color.to_string().to_lower()))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -366,7 +366,7 @@ pub fn Pen::color(self : Pen, color : Color) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyString::from(color.to_string().to_lower()))
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -377,7 +377,7 @@ pub fn Pen::isdown(self : Pen) -> Bool {
     println("Failed to get Pen::isdown method") // Return a default value
     return false
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyBool(b))
   b.to_bool()
 }
@@ -389,7 +389,7 @@ pub fn Pen::show(self : Pen) -> Unit {
     println("Failed to get Pen::showturtle method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -400,7 +400,7 @@ pub fn Pen::isvisible(self : Pen) -> Bool {
     println("Failed to get Pen::isvisible method") // Return a default value
     return false
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyBool(b))
   b.to_bool()
 }
@@ -412,7 +412,7 @@ pub fn Pen::begin_fill(self : Pen) -> Unit {
     println("Failed to get Pen::begin_fill method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -423,7 +423,7 @@ pub fn Pen::end_fill(self : Pen) -> Unit {
     println("Failed to get Pen::end_fill method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -453,7 +453,7 @@ pub fn Pen::circle(
     Some(s) => kwargs.set("steps", PyInteger::from(s.to_int64()))
     None => ()
   }
-  let _ = func.invoke?(args~, kwargs~)
+  let _ = try? func.invoke(args~, kwargs~)
 
 }
 
@@ -466,7 +466,7 @@ pub fn Pen::stamp(self : Pen) -> Int {
     println("Failed to get Pen::stamp method") // Return a default error value
     return -1
   }
-  let res = func.invoke?().unwrap()
+  let res = (try? func.invoke()).unwrap()
   guard res is Some(PyInteger(i)) else {
     println("Pen::stamp did not return an integer") // Return a default error value
     return -1
@@ -484,7 +484,7 @@ pub fn Pen::clearstamp(self : Pen, stamp_id : Int) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyInteger::from(stamp_id.to_int64()))
-  let _ = func.invoke?(args~).unwrap()
+  let _ = (try? func.invoke(args~)).unwrap()
 
 }
 
@@ -505,7 +505,7 @@ pub fn Pen::clearstamps(self : Pen, n~ : Int? = None) -> Unit {
   // Although Python's clearstamps takes n as positional or keyword,
   // passing it as keyword is safer with Option handling.
   // We invoke with an empty args tuple and the kwargs dictionary.
-  let _ = func.invoke?(kwargs~).unwrap()
+  let _ = (try? func.invoke(kwargs~)).unwrap()
 
 }
 
@@ -516,7 +516,7 @@ pub fn Pen::reset(self : Pen) -> Unit {
     println("Failed to get Pen::reset method")
     return
   }
-  let _ = func.invoke?()
+  let _ = try? func.invoke()
 
 }
 
@@ -530,7 +530,7 @@ pub fn Pen::shape(self : Pen, name : Shape) -> Unit {
   }
   let args = PyTuple::new(1)
   args..set(0, PyString::from(name.to_string().to_lower())) // Assuming Shape enum with Show derived
-  let _ = func.invoke?(args~)
+  let _ = try? func.invoke(args~)
 
 }
 
@@ -562,6 +562,6 @@ pub fn Pen::shapesize(
     Some(o) => kwargs.set("outline", PyInteger::from(o.to_int64()))
     None => ()
   }
-  let _ = func.invoke?(kwargs~)
+  let _ = try? func.invoke(kwargs~)
 
 }
diff --git a/turtle/screen.mbt b/turtle/screen.mbt
index b664da6..b7cb671 100644
--- a/turtle/screen.mbt
+++ b/turtle/screen.mbt
@@ -7,7 +7,7 @@ pub struct Screen {
 pub fn Screen::new() -> Screen {
   let lib = singleton()
   guard lib.turtle.get_attr("Screen") is Some(PyCallable(createScreen))
-  guard createScreen.invoke?().unwrap() is Some(PyClass(screen))
+  guard (try? createScreen.invoke()).unwrap() is Some(PyClass(screen))
   Screen::{ screen, }
 }
 
@@ -16,7 +16,7 @@ pub fn Screen::setup(self : Screen, width : Double, height : Double) -> Unit {
   guard self.screen.get_attr("setup") is Some(PyCallable(setup))
   let args = PyTuple::new(2)
   args..set(0, PyFloat::from(width))..set(1, PyFloat::from(height))
-  let _ = setup.invoke?(args~)
+  let _ = try? setup.invoke(args~)
 
 }
 
@@ -25,7 +25,7 @@ pub fn Screen::title(self : Screen, text : String) -> Unit {
   guard self.screen.get_attr("title") is Some(PyCallable(title))
   let args = PyTuple::new(1)
   args..set(0, PyString::from(text))
-  let _ = title.invoke?(args~)
+  let _ = try? title.invoke(args~)
 
 }
 
@@ -34,14 +34,14 @@ pub fn Screen::tracer(self : Screen, n : Int) -> Unit {
   guard self.screen.get_attr("tracer") is Some(PyCallable(tracer))
   let args = PyTuple::new(1)
   args..set(0, PyInteger::from(n.to_int64()))
-  let _ = tracer.invoke?(args~)
+  let _ = try? tracer.invoke(args~)
 
 }
 
 ///|
 pub fn Screen::update(self : Screen) -> Unit {
   guard self.screen.get_attr("update") is Some(PyCallable(update))
-  let _ = update.invoke?()
+  let _ = try? update.invoke()
 
 }
 
@@ -50,6 +50,6 @@ pub fn Screen::bgcolor(self : Screen, color : Color) -> Unit {
   guard self.screen.get_attr("bgcolor") is Some(PyCallable(bgcolor))
   let args = PyTuple::new(1)
   args..set(0, PyString::from(color.to_string()))
-  let _ = bgcolor.invoke?(args~)
+  let _ = try? bgcolor.invoke(args~)
 
 }