Merge pull request optuna#6086 from AdrianStrymer/use-type-checking

Implement Type-Checking for `optuna/distributions.py`

Author: nabenabe0928

optuna/distributions.py

@@ -1,20 +1,24 @@
 from __future__ import annotations
 
 import abc
-from collections.abc import Sequence
 import copy
 import decimal
 import json
 import math
 from numbers import Real
 from typing import Any
 from typing import cast
+from typing import TYPE_CHECKING
 from typing import Union
 import warnings
 
 from optuna._deprecated import deprecated_class
 
 
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+
 CategoricalChoiceType = Union[None, bool, int, float, str]
 
 
@@ -304,7 +308,7 @@ def q(self) -> float:
         :class:`~optuna.distributions.FloatDistribution`.
         This property is a proxy for its ``step`` attribute.
         """
-        return cast(float, self.step)
+        return cast("float", self.step)
 
     @q.setter
     def q(self, v: float) -> None: