Allow path-like objects in the margin cache argument (#353)

* Allow for Path objects in margin_cache argument

* Add case in unit test

src/lsdb/loaders/hipscat/hipscat_loading_config.py

@@ -4,6 +4,7 @@
 from typing import Callable, List
 
 import pandas as pd
+from hipscat.io.file_io import FilePointer
 from pandas.io._util import _arrow_dtype_mapping
 
 from lsdb.catalog.margin_catalog import MarginCatalog
@@ -23,7 +24,7 @@ class HipscatLoadingConfig:
     columns: List[str] | None = None
     """Columns to load from the catalog. If not specified, all columns are loaded"""
 
-    margin_cache: MarginCatalog | str | None = None
+    margin_cache: MarginCatalog | FilePointer | None = None
     """Margin cache for the catalog. It can be provided as a path for the margin on disk,
     or as a margin object instance. By default, it is None."""
 
@@ -35,8 +36,6 @@ class HipscatLoadingConfig:
     """Extra kwargs for the pandas parquet file reader"""
 
     def __post_init__(self):
-        if self.margin_cache is not None and not isinstance(self.margin_cache, (MarginCatalog, str)):
-            raise ValueError("`margin_cache` must be of type 'MarginCatalog' or 'str'")
         if self.dtype_backend not in ["pyarrow", "numpy_nullable", None]:
             raise ValueError("The data type backend must be either 'pyarrow' or 'numpy_nullable'")
 

src/lsdb/loaders/hipscat/read_hipscat.py

@@ -6,6 +6,7 @@
 import hipscat as hc
 from hipscat.catalog import CatalogType
 from hipscat.catalog.dataset import BaseCatalogInfo
+from hipscat.io.file_io import FilePointer
 
 from lsdb.catalog.association_catalog import AssociationCatalog
 from lsdb.catalog.catalog import Catalog
@@ -26,11 +27,11 @@
 
 # pylint: disable=unused-argument
 def read_hipscat(
-    path: str,
+    path: FilePointer,
     catalog_type: Type[CatalogTypeVar] | None = None,
     search_filter: AbstractSearch | None = None,
     columns: List[str] | None = None,
-    margin_cache: MarginCatalog | str | None = None,
+    margin_cache: MarginCatalog | FilePointer | None = None,
     dtype_backend: str | None = "pyarrow",
     storage_options: dict | None = None,
     **kwargs,
@@ -50,16 +51,16 @@ def read_hipscat(
         )
 
     Args:
-        path (str): The path that locates the root of the HiPSCat catalog
+        path (FilePointer): The path that locates the root of the HiPSCat catalog
         catalog_type (Type[Dataset]): Default `None`. By default, the type of the catalog is loaded
             from the catalog info and the corresponding object type is returned. Python's type hints
             cannot allow a return type specified by a loaded value, so to use the correct return
             type for type checking, the type of the catalog can be specified here. Use by specifying
             the lsdb class for that catalog.
         search_filter (Type[AbstractSearch]): Default `None`. The filter method to be applied.
         columns (List[str]): Default `None`. The set of columns to filter the catalog on.
-        margin_cache (MarginCatalog | str): The margin cache for the main catalog, provided as a path
-            on disk or as an instance of the MarginCatalog object. Defaults to None.
+        margin_cache (MarginCatalog | FilePointer): The margin cache for the main catalog, provided
+            as a path on disk or as an instance of the MarginCatalog object. Defaults to None.
         dtype_backend (str): Backend data type to apply to the catalog.
             Defaults to "pyarrow". If None, no type conversion is performed.
         storage_options (dict): Dictionary that contains abstract filesystem credentials

src/lsdb/loaders/hipscat/read_hipscat.pyi

@@ -15,17 +15,19 @@ from __future__ import annotations
 
 from typing import List, Type, overload
 
+from hipscat.io.file_io import FilePointer
+
 from lsdb.catalog.dataset.dataset import Dataset
 from lsdb.catalog.margin_catalog import MarginCatalog
 from lsdb.core.search.abstract_search import AbstractSearch
 from lsdb.loaders.hipscat.abstract_catalog_loader import CatalogTypeVar
 
 @overload
 def read_hipscat(
-    path: str,
+    path: FilePointer,
     search_filter: AbstractSearch | None = None,
     columns: List[str] | None = None,
-    margin_cache: MarginCatalog | str | None = None,
+    margin_cache: MarginCatalog | FilePointer | None = None,
     dtype_backend: str | None = "pyarrow",
     storage_options: dict | None = None,
     **kwargs,
@@ -36,7 +38,7 @@ def read_hipscat(
     catalog_type: Type[CatalogTypeVar],
     search_filter: AbstractSearch | None = None,
     columns: List[str] | None = None,
-    margin_cache: MarginCatalog | str | None = None,
+    margin_cache: MarginCatalog | FilePointer | None = None,
     dtype_backend: str | None = "pyarrow",
     storage_options: dict | None = None,
     **kwargs,

tests/lsdb/loaders/hipscat/test_read_hipscat.py

@@ -1,3 +1,5 @@
+from pathlib import Path
+
 import hipscat as hc
 import numpy as np
 import numpy.testing as npt
@@ -82,6 +84,9 @@ def test_catalog_with_margin(
     # Provide the margin cache catalog path
     catalog_2 = lsdb.read_hipscat(small_sky_xmatch_dir, margin_cache=small_sky_xmatch_margin_dir)
     assert isinstance(catalog_2, lsdb.Catalog)
+    # Which can also be provided with a Path object
+    catalog_3 = lsdb.read_hipscat(small_sky_xmatch_dir, margin_cache=Path(small_sky_xmatch_margin_dir))
+    assert isinstance(catalog_3, lsdb.Catalog)
     # The catalogs obtained are identical
     assert catalog.margin.hc_structure.catalog_info == catalog_2.margin.hc_structure.catalog_info
     assert catalog.margin.get_healpix_pixels() == catalog_2.margin.get_healpix_pixels()
@@ -94,11 +99,6 @@ def test_catalog_without_margin_is_none(small_sky_xmatch_dir):
     assert catalog.margin is None
 
 
-def test_catalog_with_wrong_margin_args(small_sky_xmatch_dir):
-    with pytest.raises(ValueError, match="must be of type"):
-        lsdb.read_hipscat(small_sky_xmatch_dir, margin_cache=1)
-
-
 def test_read_hipscat_subset_with_cone_search(small_sky_order1_dir, small_sky_order1_catalog):
     cone_search = ConeSearch(ra=0, dec=-80, radius_arcsec=20 * 3600)
     # Filtering using catalog's cone_search