Make typing_extensions optional

optuna/_convert_positional_args.py

@@ -3,37 +3,39 @@
 from typing import Any
 from typing import Callable
 from typing import Sequence
+from typing import TYPE_CHECKING
 from typing import TypeVar
 import warnings
 
-from typing_extensions import ParamSpec
 
+if TYPE_CHECKING:
+    from typing_extensions import ParamSpec
 
-_T = TypeVar("_T")
-_P = ParamSpec("_P")
+    _P = ParamSpec("_P")
+    _T = TypeVar("_T")
 
 
 def convert_positional_args(
     *,
     previous_positional_arg_names: Sequence[str],
     warning_stacklevel: int = 2,
-) -> Callable[[Callable[_P, _T]], Callable[_P, _T]]:
+) -> "Callable[[Callable[_P, _T]], Callable[_P, _T]]":
     """Convert positional arguments to keyword arguments.
 
     Args:
         previous_positional_arg_names: List of names previously given as positional arguments.
         warning_stacklevel: Level of the stack trace where decorated function locates.
     """
 
-    def converter_decorator(func: Callable[_P, _T]) -> Callable[_P, _T]:
+    def converter_decorator(func: "Callable[_P, _T]") -> "Callable[_P, _T]":
 
         assert set(previous_positional_arg_names).issubset(set(signature(func).parameters)), (
             f"{set(previous_positional_arg_names)} is not a subset of"
             f" {set(signature(func).parameters)}"
         )
 
         @wraps(func)
-        def converter_wrapper(*args: Any, **kwargs: Any) -> _T:
+        def converter_wrapper(*args: Any, **kwargs: Any) -> "_T":
 
             if len(args) >= 1:
                 warnings.warn(

optuna/_deprecated.py

@@ -3,19 +3,22 @@
 from typing import Any
 from typing import Callable
 from typing import Optional
+from typing import TYPE_CHECKING
 from typing import TypeVar
 import warnings
 
 from packaging import version
-from typing_extensions import ParamSpec
 
 from optuna._experimental import _get_docstring_indent
 from optuna._experimental import _validate_version
 
 
-FT = TypeVar("FT")
-FP = ParamSpec("FP")
-CT = TypeVar("CT")
+if TYPE_CHECKING:
+    from typing_extensions import ParamSpec
+
+    FT = TypeVar("FT")
+    FP = ParamSpec("FP")
+    CT = TypeVar("CT")
 
 
 _DEPRECATION_NOTE_TEMPLATE = """
@@ -52,7 +55,7 @@ def deprecated_func(
     removed_version: str,
     name: Optional[str] = None,
     text: Optional[str] = None,
-) -> Callable[[Callable[FP, FT]], Callable[FP, FT]]:
+) -> "Callable[[Callable[FP, FT]], Callable[FP, FT]]":
     """Decorate function as deprecated.
 
     Args:
@@ -81,7 +84,7 @@ def deprecated_func(
     _validate_version(removed_version)
     _validate_two_version(deprecated_version, removed_version)
 
-    def decorator(func: Callable[FP, FT]) -> Callable[FP, FT]:
+    def decorator(func: "Callable[FP, FT]") -> "Callable[FP, FT]":
         if func.__doc__ is None:
             func.__doc__ = ""
 
@@ -92,7 +95,7 @@ def decorator(func: Callable[FP, FT]) -> Callable[FP, FT]:
         func.__doc__ = func.__doc__.strip() + textwrap.indent(note, indent) + indent
 
         @functools.wraps(func)
-        def wrapper(*args: Any, **kwargs: Any) -> FT:
+        def wrapper(*args: Any, **kwargs: Any) -> "FT":
             """Decorates a function as deprecated.
 
             This decorator is supposed to be applied to the deprecated function.
@@ -119,7 +122,7 @@ def deprecated_class(
     removed_version: str,
     name: Optional[str] = None,
     text: Optional[str] = None,
-) -> Callable[[CT], CT]:
+) -> "Callable[[CT], CT]":
     """Decorate class as deprecated.
 
     Args:
@@ -148,8 +151,8 @@ def deprecated_class(
     _validate_version(removed_version)
     _validate_two_version(deprecated_version, removed_version)
 
-    def decorator(cls: CT) -> CT:
-        def wrapper(cls: CT) -> CT:
+    def decorator(cls: "CT") -> "CT":
+        def wrapper(cls: "CT") -> "CT":
             """Decorates a class as deprecated.
 
             This decorator is supposed to be applied to the deprecated class.

optuna/_experimental.py

@@ -3,17 +3,20 @@
 from typing import Any
 from typing import Callable
 from typing import Optional
+from typing import TYPE_CHECKING
 from typing import TypeVar
 import warnings
 
-from typing_extensions import ParamSpec
-
 from optuna.exceptions import ExperimentalWarning
 
 
-FT = TypeVar("FT")
-FP = ParamSpec("FP")
-CT = TypeVar("CT")
+if TYPE_CHECKING:
+    from typing_extensions import ParamSpec
+
+    FT = TypeVar("FT")
+    FP = ParamSpec("FP")
+    CT = TypeVar("CT")
+
 
 _EXPERIMENTAL_NOTE_TEMPLATE = """
 
@@ -40,7 +43,7 @@ def _get_docstring_indent(docstring: str) -> str:
 def experimental_func(
     version: str,
     name: Optional[str] = None,
-) -> Callable[[Callable[FP, FT]], Callable[FP, FT]]:
+) -> "Callable[[Callable[FP, FT]], Callable[FP, FT]]":
     """Decorate function as experimental.
 
     Args:
@@ -50,7 +53,7 @@ def experimental_func(
 
     _validate_version(version)
 
-    def decorator(func: Callable[FP, FT]) -> Callable[FP, FT]:
+    def decorator(func: "Callable[FP, FT]") -> "Callable[FP, FT]":
         if func.__doc__ is None:
             func.__doc__ = ""
 
@@ -59,7 +62,7 @@ def decorator(func: Callable[FP, FT]) -> Callable[FP, FT]:
         func.__doc__ = func.__doc__.strip() + textwrap.indent(note, indent) + indent
 
         @functools.wraps(func)
-        def wrapper(*args: Any, **kwargs: Any) -> FT:
+        def wrapper(*args: Any, **kwargs: Any) -> "FT":
             warnings.warn(
                 "{} is experimental (supported from v{}). "
                 "The interface can change in the future.".format(
@@ -79,7 +82,7 @@ def wrapper(*args: Any, **kwargs: Any) -> FT:
 def experimental_class(
     version: str,
     name: Optional[str] = None,
-) -> Callable[[CT], CT]:
+) -> "Callable[[CT], CT]":
     """Decorate class as experimental.
 
     Args:
@@ -89,8 +92,8 @@ def experimental_class(
 
     _validate_version(version)
 
-    def decorator(cls: CT) -> CT:
-        def wrapper(cls: CT) -> CT:
+    def decorator(cls: "CT") -> "CT":
+        def wrapper(cls: "CT") -> "CT":
             """Decorates a class as experimental.
 
             This decorator is supposed to be applied to the experimental class.

optuna/integration/pytorch_distributed.py

@@ -6,10 +6,9 @@
 from typing import Dict
 from typing import Optional
 from typing import Sequence
+from typing import TYPE_CHECKING
 from typing import TypeVar
 
-from typing_extensions import ParamSpec
-
 import optuna
 from optuna._deprecated import deprecated_func
 from optuna._experimental import experimental_class
@@ -23,16 +22,19 @@
     import torch.distributed as dist
 
 
-_T = TypeVar("_T")
-_P = ParamSpec("_P")
+if TYPE_CHECKING:
+    from typing_extensions import ParamSpec
+
+    _T = TypeVar("_T")
+    _P = ParamSpec("_P")
 
 
 _suggest_deprecated_msg = (
     "Use :func:`~optuna.integration.TorchDistributedTrial.suggest_float` instead."
 )
 
 
-def broadcast_properties(f: Callable[_P, _T]) -> Callable[_P, _T]:
+def broadcast_properties(f: "Callable[_P, _T]") -> "Callable[_P, _T]":
     """Method decorator to fetch updated trial properties from rank 0 after ``f`` is run.
 
     This decorator ensures trial properties (params, distributions, etc.) on all distributed
@@ -42,7 +44,7 @@ def broadcast_properties(f: Callable[_P, _T]) -> Callable[_P, _T]:
     """
 
     @functools.wraps(f)
-    def wrapped(*args: _P.args, **kwargs: _P.kwargs) -> _T:
+    def wrapped(*args: "_P.args", **kwargs: "_P.kwargs") -> "_T":
         # TODO(nlgranger): Remove type ignore after mypy includes
         # https://github.com/python/mypy/pull/12668
         self: TorchDistributedTrial = args[0]  # type: ignore

setup.py

@@ -39,7 +39,6 @@ def get_install_requires() -> List[str]:
         "scipy!=1.4.0" if sys.version[:3] == "3.6" else "scipy>=1.7.0",
         "sqlalchemy>=1.1.0",
         "tqdm",
-        "typing_extensions>=3.10.0.0",
         "PyYAML",  # Only used in `optuna/cli.py`.
     ]
     return requirements
@@ -66,6 +65,7 @@ def get_extras_require() -> Dict[str, List[str]]:
             "types-PyYAML",
             "types-redis",
             "types-setuptools",
+            "typing_extensions>=3.10.0.0",
         ],
         "document": [
             "cma",