REF: Make scale.final_limit a cached property

plotnine/scales/scale.py

@@ -3,6 +3,7 @@
 from abc import ABC
 from copy import copy, deepcopy
 from dataclasses import dataclass, field
+from functools import cached_property
 from typing import TYPE_CHECKING, Generic, cast
 
 import numpy as np
@@ -271,7 +272,7 @@ def is_empty(self) -> bool:
             return True
         return self._range.is_empty() and self.limits is None
 
-    @property
+    @cached_property
     def final_limits(self) -> Any:
         raise NotImplementedError
 

plotnine/scales/scale_continuous.py

@@ -2,6 +2,7 @@
 
 from contextlib import suppress
 from dataclasses import dataclass
+from functools import cached_property
 from typing import TYPE_CHECKING, Sequence
 from warnings import warn
 
@@ -169,7 +170,7 @@ def _make_trans(self) -> trans:
 
         return t
 
-    @property
+    @cached_property
     def final_limits(self) -> tuple[float, float]:
         if self.is_empty():
             return (0, 1)

plotnine/scales/scale_discrete.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
+from functools import cached_property
 from typing import TYPE_CHECKING, Any, Literal, Sequence
 
 import numpy as np
@@ -75,7 +76,7 @@ def __post_init__(self):
         super().__post_init__()
         self._range = RangeDiscrete()
 
-    @property
+    @cached_property
     def final_limits(self) -> Sequence[str]:
         if self.is_empty():
             return ("0", "1")

plotnine/scales/scale_xy.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
+from functools import cached_property
 from itertools import chain
 from typing import TYPE_CHECKING
 
@@ -88,7 +89,7 @@ def map(self, x, limits=None):
             return list(seq)
         return list(x)
 
-    @property
+    @cached_property
     def final_limits(self):
         if self.is_empty():
             return (0, 1)