Update xrefs.py

src/pyobo/api/xrefs.py

@@ -1,6 +1,7 @@
 """High-level API for synonyms."""
 
 import logging
+import warnings
 from collections.abc import Mapping
 from functools import lru_cache
 
@@ -83,6 +84,8 @@ def get_xrefs_df(
     prefix: str, *, use_tqdm: bool = False, **kwargs: Unpack[GetOntologyKwargs]
 ) -> pd.DataFrame:
     """Get all xrefs."""
+    warnings.warn("use pyobo.get_sssom_df instead of pyobo.get_xrefs_df", DeprecationWarning, stacklevel=2)
+
     version = get_version_from_kwargs(prefix, kwargs)
     path = prefix_cache_join(prefix, name="xrefs.tsv", version=version)