diff --git a/compiler/erg_compiler/codegen.rs b/compiler/erg_compiler/codegen.rs
index 2d9ac450..39c1fc7f 100644
--- a/compiler/erg_compiler/codegen.rs
+++ b/compiler/erg_compiler/codegen.rs
@@ -196,8 +196,13 @@ fn convert_to_python_attr(class: &str, uniq_obj_name: Option<&str>, name: Str) -
         ("Array!", _, "push!") => Str::ever("append"),
         ("Complex" | "Real" | "Int" | "Nat" | "Float", _, "Real") => Str::ever("real"),
         ("Complex" | "Real" | "Int" | "Nat" | "Float", _, "Imag") => Str::ever("imag"),
+        ("StringIO!", _, "getvalue!") => Str::ever("getvalue"),
+        ("Module", Some("importlib"), "reload!") => Str::ever("reload"),
         ("Module", Some("random"), "randint!") => Str::ever("randint"),
         ("Module", Some("random"), "choice!") => Str::ever("choice"),
+        ("Module", Some("sys"), "setrecurtionlimit!") => Str::ever("setrecurtionlimit"),
+        ("Module", Some("time"), "sleep!") => Str::ever("sleep"),
+        ("Module", Some("time"), "time!") => Str::ever("time"),
         _ => name,
     }
 }
diff --git a/compiler/erg_compiler/context/initialize/importlib.rs b/compiler/erg_compiler/context/initialize/importlib.rs
new file mode 100644
index 00000000..66e7e4b8
--- /dev/null
+++ b/compiler/erg_compiler/context/initialize/importlib.rs
@@ -0,0 +1,18 @@
+use erg_common::vis::Visibility;
+
+use erg_type::constructors::proc1;
+use erg_type::Type;
+use Type::*;
+
+use crate::context::Context;
+use crate::varinfo::Mutability;
+use Mutability::*;
+use Visibility::*;
+
+impl Context {
+    pub(crate) fn init_py_importlib_mod() -> Self {
+        let mut importlib = Context::module("importlib".into(), 15);
+        importlib.register_impl("reload!", proc1(Module, NoneType), Immutable, Public);
+        importlib
+    }
+}
diff --git a/compiler/erg_compiler/context/initialize/io.rs b/compiler/erg_compiler/context/initialize/io.rs
new file mode 100644
index 00000000..00451fbe
--- /dev/null
+++ b/compiler/erg_compiler/context/initialize/io.rs
@@ -0,0 +1,26 @@
+use erg_common::vis::Visibility;
+use erg_common::Str;
+
+use erg_type::constructors::{class, pr0_met};
+use erg_type::Type;
+use Type::*;
+
+use crate::context::Context;
+use crate::varinfo::Mutability;
+use Mutability::*;
+use Visibility::*;
+
+impl Context {
+    pub(crate) fn init_py_io_mod() -> Self {
+        let mut io = Context::module("io".into(), 15);
+        let mut string_io = Context::mono_class(Str::ever("StringIO!"), vec![Obj], vec![], 0);
+        string_io.register_impl(
+            "getvalue!",
+            pr0_met(class("StringIO!"), None, Str),
+            Immutable,
+            Public,
+        );
+        io.register_type(class("StringIO!"), string_io, Const);
+        io
+    }
+}
diff --git a/compiler/erg_compiler/context/initialize/mod.rs b/compiler/erg_compiler/context/initialize/mod.rs
index 9fd2b8ee..fc145e71 100644
--- a/compiler/erg_compiler/context/initialize/mod.rs
+++ b/compiler/erg_compiler/context/initialize/mod.rs
@@ -1,8 +1,13 @@
 //! defines type information for builtin objects (in `Context`)
 //!
 //! 組み込みオブジェクトの型情報を(Contextに)定義
+pub mod importlib;
+pub mod io;
 pub mod math;
 pub mod random;
+pub mod socket;
+pub mod sys;
+pub mod time;
 
 use erg_common::set;
 use erg_common::vis::Visibility;
@@ -549,6 +554,18 @@ impl Context {
             Immutable,
             Public,
         );
+        str_.register_impl(
+            "encode",
+            fn_met(
+                Str,
+                vec![],
+                None,
+                vec![param_t("encoding", Str), param_t("errors", Str)],
+                class("Bytes"),
+            ),
+            Immutable,
+            Public,
+        );
         str_.register_const("AddO", ValueObj::t(Str));
         str_.register_const("MulO", ValueObj::t(Str));
         str_.register_const("MutType!", ValueObj::t(class("Str!")));
diff --git a/compiler/erg_compiler/context/initialize/socket.rs b/compiler/erg_compiler/context/initialize/socket.rs
new file mode 100644
index 00000000..42ec4c32
--- /dev/null
+++ b/compiler/erg_compiler/context/initialize/socket.rs
@@ -0,0 +1,36 @@
+use erg_common::vis::Visibility;
+use erg_common::Str;
+
+use erg_type::constructors::{class, func, option, param_t};
+use erg_type::Type;
+use Type::*;
+
+use crate::context::Context;
+use crate::varinfo::Mutability;
+use Mutability::*;
+use Visibility::*;
+
+impl Context {
+    pub(crate) fn init_py_socket_mod() -> Self {
+        let mut socket = Context::module("socket".into(), 15);
+        let mut sock = Context::mono_class(Str::ever("Socket!"), vec![Obj], vec![], 0);
+        sock.register_impl(
+            "new",
+            func(
+                vec![],
+                None,
+                vec![
+                    param_t("family", Int),
+                    param_t("type", Int),
+                    param_t("proto", Int),
+                    param_t("fileno", option(Int)),
+                ],
+                class("Socket!"),
+            ),
+            Immutable,
+            Public,
+        );
+        socket.register_type(class("Socket!"), sock, Const);
+        socket
+    }
+}
diff --git a/compiler/erg_compiler/context/initialize/sys.rs b/compiler/erg_compiler/context/initialize/sys.rs
new file mode 100644
index 00000000..1ad02502
--- /dev/null
+++ b/compiler/erg_compiler/context/initialize/sys.rs
@@ -0,0 +1,50 @@
+use erg_common::vis::Visibility;
+
+use erg_type::constructors::{array, array_mut, class, func0, func1, proc1};
+use erg_type::typaram::TyParam;
+use erg_type::Type;
+use Type::*;
+
+use crate::context::Context;
+use crate::varinfo::Mutability;
+use Mutability::*;
+use Visibility::*;
+
+impl Context {
+    pub(crate) fn init_py_sys_mod() -> Self {
+        let mut sys = Context::module("sys".into(), 15);
+        sys.register_impl("argv", array(Str, TyParam::erased(Nat)), Immutable, Public);
+        sys.register_impl("byteorder", Str, Immutable, Public);
+        sys.register_impl(
+            "builtin_module_names",
+            array(Str, TyParam::erased(Nat)),
+            Immutable,
+            Public,
+        );
+        sys.register_impl("copyright", Str, Immutable, Public);
+        sys.register_impl("executable", Str, Immutable, Public);
+        sys.register_impl("exit", func1(Int, Never), Immutable, Public);
+        sys.register_impl("getdefaultencoding", func0(Str), Immutable, Public);
+        sys.register_impl(
+            "path",
+            array_mut(Str, TyParam::erased(Nat)),
+            Immutable,
+            Public,
+        );
+        sys.register_impl("platform", Str, Immutable, Public);
+        sys.register_impl("prefix", Str, Immutable, Public);
+        sys.register_impl("ps1", class("Str!"), Immutable, Public);
+        sys.register_impl("ps2", class("Str!"), Immutable, Public);
+        sys.register_impl(
+            "setrecursionlimit!",
+            proc1(Int, NoneType),
+            Immutable,
+            Public,
+        );
+        sys.register_impl("stderr", class("TextIOWrapper!"), Immutable, Public);
+        sys.register_impl("stdin", class("TextIOWrapper!"), Immutable, Public);
+        sys.register_impl("stdout", class("TextIOWrapper!"), Immutable, Public);
+        sys.register_impl("version", Str, Immutable, Public);
+        sys
+    }
+}
diff --git a/compiler/erg_compiler/context/initialize/time.rs b/compiler/erg_compiler/context/initialize/time.rs
new file mode 100644
index 00000000..4609eb0d
--- /dev/null
+++ b/compiler/erg_compiler/context/initialize/time.rs
@@ -0,0 +1,19 @@
+use erg_common::vis::Visibility;
+
+use erg_type::constructors::{proc0, proc1};
+use erg_type::Type;
+use Type::*;
+
+use crate::context::Context;
+use crate::varinfo::Mutability;
+use Mutability::*;
+use Visibility::*;
+
+impl Context {
+    pub(crate) fn init_py_time_mod() -> Self {
+        let mut time = Context::module("time".into(), 15);
+        time.register_impl("sleep!", proc1(Float, NoneType), Immutable, Public);
+        time.register_impl("time!", proc0(Float), Immutable, Public);
+        time
+    }
+}
diff --git a/compiler/erg_compiler/context/register.rs b/compiler/erg_compiler/context/register.rs
index 28723cb5..2ff67b7d 100644
--- a/compiler/erg_compiler/context/register.rs
+++ b/compiler/erg_compiler/context/register.rs
@@ -359,6 +359,13 @@ impl Context {
                 if self.rec_subtype_of(&lit.value.class(), &Str) {
                     let name = enum_unwrap!(lit.value.clone(), ValueObj::Str);
                     match &name[..] {
+                        "importlib" => {
+                            self.mods
+                                .insert(var_name.clone(), Self::init_py_importlib_mod());
+                        }
+                        "io" => {
+                            self.mods.insert(var_name.clone(), Self::init_py_io_mod());
+                        }
                         "math" => {
                             self.mods.insert(var_name.clone(), Self::init_py_math_mod());
                         }
@@ -366,6 +373,16 @@ impl Context {
                             self.mods
                                 .insert(var_name.clone(), Self::init_py_random_mod());
                         }
+                        "socket" => {
+                            self.mods
+                                .insert(var_name.clone(), Self::init_py_socket_mod());
+                        }
+                        "sys" => {
+                            self.mods.insert(var_name.clone(), Self::init_py_sys_mod());
+                        }
+                        "time" => {
+                            self.mods.insert(var_name.clone(), Self::init_py_time_mod());
+                        }
                         other => todo!("importing {other}"),
                     }
                 } else {
diff --git a/compiler/erg_type/constructors.rs b/compiler/erg_type/constructors.rs
index 982389fd..756df604 100644
--- a/compiler/erg_type/constructors.rs
+++ b/compiler/erg_type/constructors.rs
@@ -141,6 +141,10 @@ pub fn func(
     ))
 }
 
+pub fn func0(return_t: Type) -> Type {
+    func(vec![], None, vec![], return_t)
+}
+
 pub fn func1(param_t: Type, return_t: Type) -> Type {
     func(vec![ParamTy::anonymous(param_t)], None, vec![], return_t)
 }
@@ -184,6 +188,10 @@ pub fn proc(
     ))
 }
 
+pub fn proc0(return_t: Type) -> Type {
+    proc(vec![], None, vec![], return_t)
+}
+
 pub fn proc1(param_t: Type, return_t: Type) -> Type {
     proc(vec![ParamTy::anonymous(param_t)], None, vec![], return_t)
 }