Use typing.get_args when possible

Author: jsignell

xarray/core/alignment.py

@@ -5,7 +5,7 @@
 from collections import defaultdict
 from collections.abc import Callable, Hashable, Iterable, Mapping
 from contextlib import suppress
-from typing import TYPE_CHECKING, Any, Final, Generic, TypeVar, cast, overload
+from typing import TYPE_CHECKING, Any, Final, Generic, TypeVar, cast, get_args, overload
 
 import numpy as np
 import pandas as pd
@@ -19,7 +19,7 @@
     indexes_all_equal,
     safe_cast_to_index,
 )
-from xarray.core.types import T_Alignable
+from xarray.core.types import JoinOptions, T_Alignable
 from xarray.core.utils import emit_user_level_warning, is_dict_like, is_full_slice
 from xarray.core.variable import Variable, as_compatible_data, calculate_dimensions
 from xarray.util.deprecation_helpers import CombineKwargDefault
@@ -113,7 +113,7 @@ class Aligner(Generic[T_Alignable]):
     objects: tuple[T_Alignable, ...]
     results: tuple[T_Alignable, ...]
     objects_matching_indexes: tuple[dict[MatchingIndexKey, Index], ...]
-    join: str | CombineKwargDefault
+    join: JoinOptions | CombineKwargDefault
     exclude_dims: frozenset[Hashable]
     exclude_vars: frozenset[Hashable]
     copy: bool
@@ -133,7 +133,7 @@ class Aligner(Generic[T_Alignable]):
     def __init__(
         self,
         objects: Iterable[T_Alignable],
-        join: str | CombineKwargDefault = "inner",
+        join: JoinOptions | CombineKwargDefault = "inner",
         indexes: Mapping[Any, Any] | None = None,
         exclude_dims: str | Iterable[Hashable] = frozenset(),
         exclude_vars: Iterable[Hashable] = frozenset(),
@@ -146,14 +146,9 @@ def __init__(
         self.objects = tuple(objects)
         self.objects_matching_indexes = ()
 
-        if not isinstance(join, CombineKwargDefault) and join not in [
-            "inner",
-            "outer",
-            "override",
-            "exact",
-            "left",
-            "right",
-        ]:
+        if not isinstance(join, CombineKwargDefault) and join not in get_args(
+            JoinOptions
+        ):
             raise ValueError(f"invalid value for join: {join}")
         self.join = join
 

xarray/core/concat.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from collections.abc import Hashable, Iterable
-from typing import TYPE_CHECKING, Any, Union, overload
+from typing import Any, Literal, get_args, overload
 
 import numpy as np
 import pandas as pd
@@ -12,12 +12,18 @@
 from xarray.core.duck_array_ops import lazy_array_equiv
 from xarray.core.indexes import Index, PandasIndex
 from xarray.core.merge import (
-    _VALID_COMPAT,
     collect_variables_and_indexes,
     merge_attrs,
     merge_collected,
 )
-from xarray.core.types import T_DataArray, T_Dataset, T_Variable
+from xarray.core.types import (
+    CombineAttrsOptions,
+    ConcatOptions,
+    JoinOptions,
+    T_DataArray,
+    T_Dataset,
+    T_Variable,
+)
 from xarray.core.utils import emit_user_level_warning
 from xarray.core.variable import Variable
 from xarray.core.variable import concat as concat_vars
@@ -29,15 +35,10 @@
     CombineKwargDefault,
 )
 
-if TYPE_CHECKING:
-    from xarray.core.types import (
-        CombineAttrsOptions,
-        CompatOptions,
-        ConcatOptions,
-        JoinOptions,
-    )
-
-    T_DataVars = Union[ConcatOptions, Iterable[Hashable]]
+T_DataVars = ConcatOptions | Iterable[Hashable]
+CompatOptions = Literal[
+    "identical", "equals", "broadcast_equals", "no_conflicts", "override"
+]
 
 
 # TODO: replace dim: Any by 1D array_likes
@@ -267,11 +268,11 @@ def concat(
     except StopIteration as err:
         raise ValueError("must supply at least one object to concatenate") from err
 
-    if not isinstance(compat, CombineKwargDefault) and compat not in set(
-        _VALID_COMPAT
-    ) - {"minimal"}:
+    if not isinstance(compat, CombineKwargDefault) and compat not in get_args(
+        CompatOptions
+    ):
         raise ValueError(
-            f"compat={compat!r} invalid: must be 'broadcast_equals', 'equals', 'identical', 'no_conflicts' or 'override'"
+            f"compat={compat!r} invalid: valid options: {get_args(CompatOptions)}"
         )
 
     if isinstance(first_obj, DataArray):
@@ -559,13 +560,6 @@ def _dataset_concat(
             "The elements in the input list need to be either all 'Dataset's or all 'DataArray's"
         )
 
-    if not isinstance(compat, CombineKwargDefault) and compat not in set(
-        _VALID_COMPAT
-    ) - {"minimal"}:
-        raise ValueError(
-            f"compat={compat!r} invalid: must be 'broadcast_equals', 'equals', 'identical', 'no_conflicts' or 'override'"
-        )
-
     if isinstance(dim, DataArray):
         dim_var = dim.variable
     elif isinstance(dim, Variable):