Support for pathlib.Path and s3path.S3Path objects in asdf_cut() (#119)

Support for pathlib.Path and s3path.S3Path objects in `asdf_cut`

CHANGES.rst

@@ -1,4 +1,9 @@
-0.11.0 (Unreleased)
+0.12.0 (Unreleased)
+--------------------
+
+- asdf_cut() function now accepts pathlib.Path and s3path.S3Path objects as an input file [#119]
+
+0.11.0 (2024-05-28)
 --------------------
 
 - Add functionality for creating cutouts from the ASDF file format [#105]

astrocut/asdf_cutouts.py

@@ -10,18 +10,19 @@
 import gwcs
 import numpy as np
 import s3fs
+from s3path import S3Path
 
 from astropy.coordinates import SkyCoord
 from astropy.modeling import models
 
 
-def _get_cloud_http(s3_uri: str) -> str:
+def _get_cloud_http(s3_uri: Union[str, S3Path]) -> str:
     """ 
     Get the HTTP URI of a cloud resource from an S3 URI.
 
     Parameters
     ----------
-    s3_uri : string
+    s3_uri : string | S3Path
         the S3 URI of the cloud resource
     """
     # create file system
@@ -239,8 +240,8 @@ def _write_asdf(cutout: astropy.nddata.Cutout2D, gwcsobj: gwcs.wcs.WCS, outfile:
     af.write_to(outfile)
 
 
-def asdf_cut(input_file: str, ra: float, dec: float, cutout_size: int = 20,
-             output_file: str = "example_roman_cutout.fits",
+def asdf_cut(input_file: Union[str, pathlib.Path, S3Path], ra: float, dec: float, cutout_size: int = 20,
+             output_file: Union[str, pathlib.Path] = "example_roman_cutout.fits",
              write_file: bool = True, fill_value: Union[int, float] = np.nan) -> astropy.nddata.Cutout2D:
     """ 
     Takes a single ASDF input file (`input_file`) and generates a cutout of designated size `cutout_size`
@@ -250,15 +251,15 @@ def asdf_cut(input_file: str, ra: float, dec: float, cutout_size: int = 20,
 
     Parameters
     ----------
-    input_file : str
+    input_file : str | Path | S3Path
         The input ASDF file.
     ra : float
         The right ascension of the central cutout.
     dec : float
         The declination of the central cutout.
     cutout_size : int
         Optional, default 20. The image cutout pixel size.
-    output_file : str
+    output_file : str | Path
         Optional, default "example_roman_cutout.fits". The name of the output cutout file.
     write_file : bool
         Optional, default True. Flag to write the cutout to a file or not.
@@ -273,7 +274,7 @@ def asdf_cut(input_file: str, ra: float, dec: float, cutout_size: int = 20,
 
     # if file comes from AWS cloud bucket, get HTTP URL to open with asdf
     file = input_file
-    if isinstance(input_file, str) and input_file.startswith('s3://'):
+    if (isinstance(input_file, str) and input_file.startswith('s3://')) or isinstance(input_file, S3Path):
         file = _get_cloud_http(input_file)
 
     # get the 2d image data

astrocut/tests/test_asdf_cut.py

@@ -13,6 +13,7 @@
 from astropy.wcs.utils import pixel_to_skycoord
 from gwcs import wcs
 from gwcs import coordinate_frames as cf
+from s3path import S3Path
 from astrocut.asdf_cutouts import get_center_pixel, asdf_cut, _get_cutout, _slice_gwcs, _get_cloud_http
 
 
@@ -325,10 +326,16 @@ def test_get_cloud_http(mock_s3fs):
     mock_fs.open.return_value.__enter__.return_value = mock_file
     mock_s3fs.return_value = mock_fs
 
+    # test function with string input
     s3_uri = "s3://test_bucket/test_file.asdf"
     http_uri = _get_cloud_http(s3_uri)
-
     assert http_uri == HTTP_URI
     mock_s3fs.assert_called_once_with()
     mock_fs.open.assert_called_once_with(s3_uri, 'rb')
     mock_file.url.assert_called_once()
+
+    # test function with S3Path input
+    s3_uri_path = S3Path("test_bucket/test_file_2.asdf")
+    http_uri_path = _get_cloud_http(s3_uri_path)
+    assert http_uri_path == HTTP_URI
+    mock_fs.open.assert_called_with(s3_uri_path, 'rb')

setup.cfg

@@ -20,6 +20,7 @@ install_requires =
     astropy>=5.2 # astropy with s3fs support
     fsspec[http]>=2022.8.2  # for remote cutouts
     s3fs>=2022.8.2  # for remote cutouts
+    s3path>=0.5.7 # for remote file paths
     roman_datamodels>=0.17.0 # for roman file support
     scipy
     Pillow