mypy and ruff fix

core/builtin_funcs.py

@@ -97,15 +97,20 @@ def execute_print(self, exec_ctx: Context) -> RTResult[Value]:
     @args(["value"])
     def execute_print_ret(self, exec_ctx: Context) -> RTResult[Value]:
         return RTResult[Value]().success(String(str(exec_ctx.symbol_table.get("value"))))
-    
+
     @args(["value"])
-    def execute_len(self,exec_ctx: Context) -> RTResult[Value]:
+    def execute_len(self, exec_ctx: Context) -> RTResult[Value]:
         val = exec_ctx.symbol_table.get("value")
         try:
-            ret = int(len(val))
-            return RTResult[Value]().success(Number(ret))
+            if val is not None and not val.__class__ is Value:
+                if hasattr(val, "__len__"):
+                    ret = int(val.__len__())
+                else:
+                    raise TypeError()
+                return RTResult[Value]().success(Number(ret))
+            raise TypeError()
         except TypeError:
-            return RTResult[Value]().failure(Error(self.pos_start,self.pos_end,"TypeError","Object has no len()"))
+            return RTResult[Value]().failure(Error(self.pos_start, self.pos_end, "TypeError", "Object has no len()"))
 
     @args(["value"])
     def execute_input(self, exec_ctx: Context) -> RTResult[Value]:
@@ -561,7 +566,7 @@ def create_global_symbol_table() -> SymbolTable:
     ret.set("cls", BuiltInFunction("clear"))
     ret.set("require", BuiltInFunction("require"))
     ret.set("exit", BuiltInFunction("exit"))
-    ret.set("len",BuiltInFunction("len"))
+    ret.set("len", BuiltInFunction("len"))
     # Datatype validator methods
     ret.set("is_num", BuiltInFunction("is_num"))
     ret.set("is_int", BuiltInFunction("is_int"))

core/datatypes.py

@@ -133,8 +133,9 @@ class Iterator(Value):
     def __init__(self, generator: Generator[RTResult[Value], None, None]) -> None:
         super().__init__()
         self.it = generator
-
-    def __len__(self): return len(self.it)
+
+    def __len__(self):
+        return len(self.it)
 
     def iter(self) -> Iterator:
         return self