diff --git a/compiler/erg_compiler/codegen.rs b/compiler/erg_compiler/codegen.rs
index 952c343e..89cd62a0 100644
--- a/compiler/erg_compiler/codegen.rs
+++ b/compiler/erg_compiler/codegen.rs
@@ -2495,6 +2495,7 @@ impl PyCodeGenerator {
                 self.emit_expr(*tasc.expr);
             }
             Expr::Import(acc) => self.emit_import(acc),
+            Expr::Dummy(_) => {}
         }
     }
 
diff --git a/compiler/erg_compiler/context/tyvar.rs b/compiler/erg_compiler/context/tyvar.rs
index 8e6a7eed..128cf06c 100644
--- a/compiler/erg_compiler/context/tyvar.rs
+++ b/compiler/erg_compiler/context/tyvar.rs
@@ -621,7 +621,7 @@ impl Context {
 
     fn resolve_expr_t(&self, expr: &mut hir::Expr) -> SingleTyCheckResult<()> {
         match expr {
-            hir::Expr::Lit(_) => Ok(()),
+            hir::Expr::Lit(_) | hir::Expr::Dummy(_) => Ok(()),
             hir::Expr::Accessor(acc) => {
                 let loc = acc.loc();
                 let t = acc.ref_mut_t();
diff --git a/compiler/erg_compiler/effectcheck.rs b/compiler/erg_compiler/effectcheck.rs
index 246e84ed..44ab931d 100644
--- a/compiler/erg_compiler/effectcheck.rs
+++ b/compiler/erg_compiler/effectcheck.rs
@@ -191,7 +191,11 @@ impl SideEffectChecker {
                     self.path_stack.pop();
                     self.block_stack.pop();
                 }
-                other => todo!("{other}"),
+                Expr::AttrDef(_)
+                | Expr::Code(_)
+                | Expr::Compound(_)
+                | Expr::Import(_)
+                | Expr::Dummy(_) => {}
             }
         }
         log!(info "the side-effects checking process has completed, found errors: {}{RESET}", self.errs.len());
@@ -275,6 +279,7 @@ impl SideEffectChecker {
     /// ```
     fn check_expr(&mut self, expr: &Expr) {
         match expr {
+            Expr::Lit(_) => {}
             Expr::Def(def) => {
                 self.check_def(def);
             }
@@ -399,7 +404,11 @@ impl SideEffectChecker {
                     ));
                 }
             }
-            _ => {}
+            Expr::AttrDef(_)
+            | Expr::Code(_)
+            | Expr::Compound(_)
+            | Expr::Import(_)
+            | Expr::Dummy(_) => {}
         }
     }
 }
diff --git a/compiler/erg_compiler/hir.rs b/compiler/erg_compiler/hir.rs
index 67e5293a..aa6be0e7 100644
--- a/compiler/erg_compiler/hir.rs
+++ b/compiler/erg_compiler/hir.rs
@@ -2225,13 +2225,14 @@ pub enum Expr {
     Code(Block),     // code object
     Compound(Block), // compound statement
     Import(Accessor),
+    Dummy(Block), // for mapping to Python AST
 }
 
-impl_nested_display_for_chunk_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import);
-impl_no_type_display_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import);
+impl_nested_display_for_chunk_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import, Dummy);
+impl_no_type_display_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import, Dummy);
 impl_display_from_nested!(Expr);
-impl_locational_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import);
-impl_t_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import);
+impl_locational_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import, Dummy);
+impl_t_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Record, BinOp, UnaryOp, Call, Lambda, Def, ClassDef, PatchDef, AttrDef, Code, Compound, TypeAsc, Set, Import, Dummy);
 
 impl Default for Expr {
     fn default() -> Self {
diff --git a/compiler/erg_compiler/link.rs b/compiler/erg_compiler/link.rs
index fae37ead..f9455e30 100644
--- a/compiler/erg_compiler/link.rs
+++ b/compiler/erg_compiler/link.rs
@@ -158,6 +158,7 @@ impl<'a> Linker<'a> {
                 }
             }
             Expr::Import(_) => unreachable!(),
+            Expr::Dummy(_) => {}
         }
     }
 
@@ -279,6 +280,7 @@ impl<'a> Linker<'a> {
                 }
             }
             Expr::Import(_) => unreachable!(),
+            Expr::Dummy(_) => {}
         }
     }
 
diff --git a/compiler/erg_compiler/lower.rs b/compiler/erg_compiler/lower.rs
index 498e1421..34b5785f 100644
--- a/compiler/erg_compiler/lower.rs
+++ b/compiler/erg_compiler/lower.rs
@@ -1765,6 +1765,8 @@ impl ASTLowerer {
             ast::Expr::PatchDef(defs) => Ok(hir::Expr::PatchDef(self.lower_patch_def(defs)?)),
             ast::Expr::AttrDef(adef) => Ok(hir::Expr::AttrDef(self.lower_attr_def(adef)?)),
             ast::Expr::TypeAsc(tasc) => Ok(hir::Expr::TypeAsc(self.lower_type_asc(tasc)?)),
+            // Checking is also performed for expressions in Dummy. However, it has no meaning in code generation
+            ast::Expr::Dummy(dummy) => Ok(hir::Expr::Dummy(self.lower_block(dummy)?)),
             other => todo!("{other}"),
         }
     }
diff --git a/compiler/erg_compiler/transpile.rs b/compiler/erg_compiler/transpile.rs
index af1edeb1..62692769 100644
--- a/compiler/erg_compiler/transpile.rs
+++ b/compiler/erg_compiler/transpile.rs
@@ -411,6 +411,7 @@ impl ScriptGenerator {
             }
             Expr::TypeAsc(tasc) => self.transpile_expr(*tasc.expr),
             Expr::Code(_) => todo!("transpiling importing user-defined code"),
+            Expr::Dummy(_) => "".to_string(),
         }
     }
 
diff --git a/compiler/erg_parser/ast.rs b/compiler/erg_parser/ast.rs
index 5b4ab6bc..6b7fb9f7 100644
--- a/compiler/erg_parser/ast.rs
+++ b/compiler/erg_parser/ast.rs
@@ -3527,11 +3527,13 @@ pub enum Expr {
     ClassDef(ClassDef),
     PatchDef(PatchDef),
     AttrDef(AttrDef),
+    /// for mapping to Python AST
+    Dummy(Block),
 }
 
-impl_nested_display_for_chunk_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Set, Record, BinOp, UnaryOp, Call, DataPack, Lambda, TypeAsc, Def, Methods, ClassDef, PatchDef, AttrDef);
+impl_nested_display_for_chunk_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Set, Record, BinOp, UnaryOp, Call, DataPack, Lambda, TypeAsc, Def, Methods, ClassDef, PatchDef, AttrDef, Dummy);
 impl_display_from_nested!(Expr);
-impl_locational_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Set, Record, BinOp, UnaryOp, Call, DataPack, Lambda, TypeAsc, Def, Methods, ClassDef, PatchDef, AttrDef);
+impl_locational_for_enum!(Expr; Lit, Accessor, Array, Tuple, Dict, Set, Record, BinOp, UnaryOp, Call, DataPack, Lambda, TypeAsc, Def, Methods, ClassDef, PatchDef, AttrDef, Dummy);
 
 impl Expr {
     pub fn is_match_call(&self) -> bool {
diff --git a/compiler/erg_parser/desugar.rs b/compiler/erg_parser/desugar.rs
index 9621f18b..fcf21a71 100644
--- a/compiler/erg_parser/desugar.rs
+++ b/compiler/erg_parser/desugar.rs
@@ -296,6 +296,13 @@ impl Desugarer {
                 Expr::Methods(Methods::new(method_defs.class, method_defs.vis, new_attrs))
             }
             Expr::Accessor(acc) => Expr::Accessor(Self::perform_desugar_acc(desugar, acc)),
+            Expr::Dummy(exprs) => {
+                let mut chunks = vec![];
+                for chunk in exprs.into_iter() {
+                    chunks.push(desugar(chunk));
+                }
+                Expr::Dummy(Block::new(chunks))
+            }
         }
     }