Update Python version requirement to 3.9 in accordance with NEP 29 (#418)

* Bump minimal Python to ≥3.8

* Drop support for 3.8

Author: basnijholt

.github/workflows/nox.yml

@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         platform: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.9", "3.10", "3.11"]
 
     steps:
     - uses: actions/checkout@v3

adaptive/learner/average_learner1D.py

@@ -3,9 +3,10 @@
 import math
 import sys
 from collections import defaultdict
+from collections.abc import Iterable, Sequence
 from copy import deepcopy
 from math import hypot
-from typing import Callable, DefaultDict, Iterable, List, Sequence, Tuple
+from typing import Callable
 
 import numpy as np
 import scipy.stats
@@ -25,8 +26,8 @@
 except ModuleNotFoundError:
     with_pandas = False
 
-Point = Tuple[int, Real]
-Points = List[Point]
+Point = tuple[int, Real]
+Points = list[Point]
 
 __all__: list[str] = ["AverageLearner1D"]
 
@@ -504,7 +505,7 @@ def tell_many(  # type: ignore[override]
             )
 
         # Create a mapping of points to a list of samples
-        mapping: DefaultDict[Real, DefaultDict[Int, Real]] = defaultdict(
+        mapping: defaultdict[Real, defaultdict[Int, Real]] = defaultdict(
             lambda: defaultdict(dict)
         )
         for (seed, x), y in zip(xs, ys):

adaptive/learner/balancing_learner.py

@@ -3,11 +3,11 @@
 import itertools
 import sys
 from collections import defaultdict
-from collections.abc import Iterable
+from collections.abc import Iterable, Sequence
 from contextlib import suppress
 from functools import partial
 from operator import itemgetter
-from typing import Any, Callable, Dict, Sequence, Tuple, Union, cast
+from typing import Any, Callable, Union, cast
 
 import numpy as np
 
@@ -21,10 +21,7 @@
 else:
     from typing_extensions import TypeAlias
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
+from typing import Literal
 
 try:
     import pandas
@@ -42,8 +39,8 @@ def dispatch(child_functions: list[Callable], arg: Any) -> Any:
 STRATEGY_TYPE: TypeAlias = Literal["loss_improvements", "loss", "npoints", "cycle"]
 
 CDIMS_TYPE: TypeAlias = Union[
-    Sequence[Dict[str, Any]],
-    Tuple[Sequence[str], Sequence[Tuple[Any, ...]]],
+    Sequence[dict[str, Any]],
+    tuple[Sequence[str], Sequence[tuple[Any, ...]]],
     None,
 ]
 

adaptive/learner/base_learner.py

@@ -2,7 +2,7 @@
 
 import abc
 from contextlib import suppress
-from typing import TYPE_CHECKING, Any, Callable, Dict, TypeVar
+from typing import TYPE_CHECKING, Any, Callable, TypeVar
 
 import cloudpickle
 
@@ -66,7 +66,7 @@ def _wrapped(loss_per_interval):
     return _wrapped
 
 
-DataType = Dict[Any, Any]
+DataType = dict[Any, Any]
 
 
 class BaseLearner(abc.ABC):

adaptive/learner/integrator_coeffs.py

@@ -3,7 +3,7 @@
 
 from collections import defaultdict
 from fractions import Fraction
-from functools import lru_cache
+from functools import cache
 
 import numpy as np
 import scipy.linalg
@@ -143,7 +143,7 @@ def calc_V(x: np.ndarray, n: int) -> np.ndarray:
     return np.array(V).T
 
 
-@lru_cache(maxsize=None)
+@cache
 def _coefficients():
     """Compute the coefficients on demand, in order to avoid doing linear algebra on import."""
     eps = np.spacing(1)

adaptive/learner/learner1D.py

@@ -4,8 +4,9 @@
 import itertools
 import math
 import sys
+from collections.abc import Sequence
 from copy import copy, deepcopy
-from typing import TYPE_CHECKING, Any, Callable, List, Optional, Sequence, Tuple, Union
+from typing import TYPE_CHECKING, Any, Callable, Optional, Union
 
 import cloudpickle
 import numpy as np
@@ -41,27 +42,27 @@
     # -- types --
 
     # Commonly used types
-    Interval: TypeAlias = Union[Tuple[float, float], Tuple[float, float, int]]
-    NeighborsType: TypeAlias = SortedDict[float, List[Optional[float]]]
+    Interval: TypeAlias = Union[tuple[float, float], tuple[float, float, int]]
+    NeighborsType: TypeAlias = SortedDict[float, list[Optional[float]]]
 
     # Types for loss_per_interval functions
-    XsType0: TypeAlias = Tuple[float, float]
-    YsType0: TypeAlias = Union[Tuple[float, float], Tuple[np.ndarray, np.ndarray]]
-    XsType1: TypeAlias = Tuple[
+    XsType0: TypeAlias = tuple[float, float]
+    YsType0: TypeAlias = Union[tuple[float, float], tuple[np.ndarray, np.ndarray]]
+    XsType1: TypeAlias = tuple[
         Optional[float], Optional[float], Optional[float], Optional[float]
     ]
     YsType1: TypeAlias = Union[
-        Tuple[Optional[float], Optional[float], Optional[float], Optional[float]],
-        Tuple[
+        tuple[Optional[float], Optional[float], Optional[float], Optional[float]],
+        tuple[
             Optional[np.ndarray],
             Optional[np.ndarray],
             Optional[np.ndarray],
             Optional[np.ndarray],
         ],
     ]
-    XsTypeN: TypeAlias = Tuple[Optional[float], ...]
+    XsTypeN: TypeAlias = tuple[Optional[float], ...]
     YsTypeN: TypeAlias = Union[
-        Tuple[Optional[float], ...], Tuple[Optional[np.ndarray], ...]
+        tuple[Optional[float], ...], tuple[Optional[np.ndarray], ...]
     ]
 
 

adaptive/learner/learner2D.py

@@ -3,9 +3,10 @@
 import itertools
 import warnings
 from collections import OrderedDict
+from collections.abc import Iterable
 from copy import copy
 from math import sqrt
-from typing import Callable, Iterable
+from typing import Callable
 
 import cloudpickle
 import numpy as np

adaptive/learner/learnerND.py

@@ -1111,7 +1111,7 @@ def _get_iso(self, level=0.0, which="surface"):
         vertices = []  # index -> (x,y,z)
         faces_or_lines = []  # tuple of indices of the corner points
 
-        @functools.lru_cache()
+        @functools.lru_cache
         def _get_vertex_index(a, b):
             vertex_a = self.tri.vertices[a]
             vertex_b = self.tri.vertices[b]

adaptive/learner/sequence_learner.py

@@ -2,7 +2,7 @@
 
 import sys
 from copy import copy
-from typing import Any, Tuple
+from typing import Any
 
 import cloudpickle
 from sortedcontainers import SortedDict, SortedSet
@@ -28,7 +28,7 @@
 else:
     from typing_extensions import TypeAlias
 
-PointType: TypeAlias = Tuple[Int, Any]
+PointType: TypeAlias = tuple[Int, Any]
 
 
 class _IgnoreFirstArgument:

adaptive/runner.py

@@ -15,7 +15,7 @@
 from contextlib import suppress
 from datetime import datetime, timedelta
 from importlib.util import find_spec
-from typing import TYPE_CHECKING, Any, Callable, Optional, Union
+from typing import TYPE_CHECKING, Any, Callable, Literal, Optional, Union
 
 import loky
 
@@ -46,11 +46,6 @@
 else:
     from typing_extensions import TypeAlias
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
-
 
 with_ipyparallel = find_spec("ipyparallel") is not None
 with_distributed = find_spec("distributed") is not None