Add type alias for projection options

Co-authored-by: Raphael Hagen <[email protected]>

ndpyramid/common.py

@@ -1,12 +1,15 @@
 import typing
+from typing import TypeAlias
 
 import pydantic
 import pyproj
 import rasterio.transform
 
+ProjectionOptions: TypeAlias = typing.Literal['web-mercator', 'equidistant-cylindrical']
+
 
 class Projection(pydantic.BaseModel):
-    name: typing.Literal['web-mercator', 'equidistant-cylindrical'] = 'web-mercator'
+    name: ProjectionOptions = 'web-mercator'
     _crs: str = pydantic.PrivateAttr()
     _proj = pydantic.PrivateAttr()
 

ndpyramid/reproject.py

@@ -1,14 +1,13 @@
 from __future__ import annotations  # noqa: F401
 
-import typing
 from collections import defaultdict
 
 import datatree as dt
 import numpy as np
 import xarray as xr
 from rasterio.warp import Resampling
 
-from .common import Projection
+from .common import Projection, ProjectionOptions
 from .utils import (
     add_metadata_and_zarr_encoding,
     get_levels,
@@ -31,7 +30,7 @@ def _da_reproject(da, *, dim, crs, resampling, transform):
 def level_reproject(
     ds: xr.Dataset,
     *,
-    projection: typing.Literal['web-mercator', 'equidistant-cylindrical'] = 'web-mercator',
+    projection: ProjectionOptions = 'web-mercator',
     level: int,
     pixels_per_tile: int = 128,
     resampling: str | dict = 'average',
@@ -121,7 +120,7 @@ def level_reproject(
 def pyramid_reproject(
     ds: xr.Dataset,
     *,
-    projection: typing.Literal['web-mercator', 'equidistant-cylindrical'] = 'web-mercator',
+    projection: ProjectionOptions = 'web-mercator',
     levels: int = None,
     pixels_per_tile: int = 128,
     other_chunks: dict = None,