switch Index to be a frozenset

.pre-commit-config.yaml

@@ -28,7 +28,7 @@ repos:
     - id: seed-isort-config
 
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: 'v0.910'
+    rev: 'v0.931'
     hooks:
     -   id: mypy
         exclude: tests

pangeo_forge_recipes/patterns.py

@@ -1,17 +1,19 @@
 """
 Filename / URL patterns.
 """
+from __future__ import annotations
 
 import inspect
 from dataclasses import dataclass, field, replace
 from enum import Enum
 from itertools import product
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
     ClassVar,
     Dict,
-    Iterable,
+    FrozenSet,
     Iterator,
     List,
     Optional,
@@ -68,7 +70,7 @@ class MergeDim:
     operation: ClassVar[CombineOp] = CombineOp.MERGE
 
 
-@dataclass(frozen=True)
+@dataclass(frozen=True, order=True)
 class DimIndex:
     """Object used to index a single dimension of a FilePattern or Recipe Chunks.
 
@@ -92,27 +94,13 @@ def __post_init__(self):
         assert self.index < self.sequence_len
 
 
-class Index(tuple):
-    """A tuple of ``DimIndex`` objects.
-    The order of the indexes doesn't matter for comparision."""
-
-    def __new__(self, args: Iterable[DimIndex]):
-        # This validation really slows things down because we call Index a lot!
-        # if not all((isinstance(a, DimIndex) for a in args)):
-        #     raise ValueError("All arguments must be DimIndex.")
-        # args_set = set(args)
-        # if len(set(args_set)) < len(tuple(args)):
-        #     raise ValueError("Duplicate argument detected.")
-        return tuple.__new__(Index, args)
-
-    def __str__(self):
-        return ",".join(str(dim) for dim in self)
-
-    def __eq__(self, other):
-        return (set(self) == set(other)) and (len(self) == len(other))
-
-    def __hash__(self):
-        return hash(frozenset(self))
+if TYPE_CHECKING:
+    # If we just do this, we can't initialize an Index by just writing
+    # Index(list_of_dims)
+    Index = FrozenSet[DimIndex]
+else:
+    # But if we just do this, it won't pass mypy 😖
+    Index = frozenset[DimIndex]
 
 
 CombineDim = Union[MergeDim, ConcatDim]

pangeo_forge_recipes/recipes/reference_hdf_zarr.py

@@ -29,6 +29,8 @@ def scan_file(chunk_key: ChunkKey, config: HDFReferenceRecipe):
     ref_fname = os.path.basename(fname + ".json")
     with file_opener(fname, **config.netcdf_storage_options) as fp:
         protocol = getattr(getattr(fp, "fs", None), "protocol", None)  # make mypy happy
+        if protocol is None:
+            raise ValueError("Couldn't determine protocol")
         target_url = unstrip_protocol(fname, protocol)
         config.metadata_cache[ref_fname] = create_hdf5_reference(fp, target_url, fname)
 

pangeo_forge_recipes/recipes/xarray_zarr.py

@@ -49,12 +49,12 @@
 
 
 def _input_metadata_fname(input_key: InputKey) -> str:
-    key_str = "-".join([f"{k.name}_{k.index}" for k in input_key])
+    key_str = "-".join([f"{k.name}_{k.index}" for k in sorted(input_key)])
     return "input-meta-" + key_str + ".json"
 
 
 def _input_reference_fname(input_key: InputKey) -> str:
-    key_str = "-".join([f"{k.name}_{k.index}" for k in input_key])
+    key_str = "-".join([f"{k.name}_{k.index}" for k in sorted(input_key)])
     return "input-reference-" + key_str + ".json"