Use Ruff TYPE_CHECKING blocks

probs/discrete/rv.py

@@ -1,13 +1,15 @@
 from __future__ import annotations
 
 import operator
-from collections.abc import Callable
 from dataclasses import dataclass, field
-from typing import Any, TypeVar, cast
+from typing import TYPE_CHECKING, Any, TypeVar, cast
 
 from probs.floats import ApproxFloat
 from probs.rv import Event, RandomVariable
 
+if TYPE_CHECKING:
+    from collections.abc import Callable
+
 T = TypeVar("T")
 
 
@@ -108,7 +110,7 @@ def pdf(self, x: float) -> float:
         because this way allows us to access the pmf's keys internally without
         accidentally adding empty values.
         """
-        return self.pmf[x] if x in self.pmf else 0
+        return self.pmf.get(x, 0)
 
     def cdf(self, x: float) -> float:
         """

probs/operations.py

@@ -1,6 +1,9 @@
 from __future__ import annotations
 
-from probs.rv import Event, RandomVariable
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from probs.rv import Event, RandomVariable
 
 SYNTAX_WARNING = (
     "The {} syntax is not supported because it adds unnecessary "

ruff.toml

@@ -1,8 +1,8 @@
 target-version = "py312"
-select = ["ALL"]
-ignore = [
-    "ANN101",  # Missing type annotation for `self` in method
-    "ANN102",  # Missing type annotation for `cls` in classmethod
+lint.select = ["ALL"]
+lint.ignore = [
+	"ANN101",  # Missing type annotation for `self` in method
+	"ANN102",  # Missing type annotation for `cls` in classmethod
 	"ANN401",  # Dynamically typed expressions (typing.Any) are disallowed
 	"C901",    # function is too complex (12 > 10)
 	"COM812",  # Trailing comma missing
@@ -15,28 +15,26 @@ ignore = [
 	"FBT003",  # Boolean positional value in function call
 	"FIX002",  # Line contains TODO
 	"ISC001",  # Isort
-    "PLR0911", # Too many return statements (11 > 6)
+	"PLR0911", # Too many return statements (11 > 6)
 	"PLR2004", # Magic value used in comparison, consider replacing 2 with a constant variable
-    "PLR0912", # Too many branches
+	"PLR0912", # Too many branches
 	"PLR0913", # Too many arguments to function call
 	"PLR0915", # Too many statements
 	"S101",    # Use of `assert` detected
 	"S311",    # Standard pseudo-random generators are not suitable for cryptographic purposes
 	"T201",    # print() found
 	"T203",    # pprint() found
-	"TCH001",  # Move application import into a type-checking block
-    "TCH003",  # Move standard library import into a type-checking block
-	"TD002",   # Missing author in TODO; try: `# TODO(<author_name>): ...`
-	"TD003",   # Missing issue link on the line following this TODO
-	"TD005",   # Missing issue description after `TODO`
-	"TRY003",  # Avoid specifying long messages outside the exception class
+	"TD002",  # Missing author in TODO; try: `# TODO(<author_name>): ...`
+	"TD003",  # Missing issue link on the line following this TODO
+	"TD005",  # Missing issue description after `TODO`
+	"TRY003", # Avoid specifying long messages outside the exception class
 
 	# Edutorch-specific ignores
-	"RUF001",  # String contains ambiguous `α`
-	"RUF002",  # Docstring contains ambiguous `α`
+	"RUF001", # String contains ambiguous `α`
+	"RUF002", # Docstring contains ambiguous `α`
 	"N802",   # Function name should be lowercase
 	"NPY002", # Replace legacy `np.random.randn` call with `np.random.Generator`
 ]
 
-[flake8-pytest-style]
+[lint.flake8-pytest-style]
 fixture-parentheses = false