allows the vp API to take PDF objects directly

validphys2/src/validphys/config.py

@@ -7,6 +7,7 @@
 import logging
 import numbers
 import pathlib
+from typing import Union
 
 import pandas as pd
 
@@ -17,6 +18,7 @@
 from reportengine.helputils import get_parser_type
 from reportengine.namespaces import NSList
 from validphys.core import (
+    PDF,
     CutsPolicy,
     DataGroupSpec,
     DataSetInput,
@@ -147,10 +149,15 @@ def _check_pdf_usable(self, pdf_name: str):
 
     @element_of("pdfs")
     @_id_with_label
-    def parse_pdf(self, name: str, unpolarized_bc=None):
+    def parse_pdf(self, name: Union[str, PDF], unpolarized_bc=None):
         """A PDF set installed in LHAPDF.
         If an unpolarized boundary condition it defined, it will be registered as part of the PDF.
+
+        If ``name`` is already an instance of a vp PDF object, return it unchanged.
         """
+        # This allows passing pdf objects to the validphys API
+        if isinstance(name, PDF):
+            return name
         pdf = self._check_pdf_usable(name)
         if unpolarized_bc is not None:
             pdf.register_boundary(unpolarized_bc=unpolarized_bc)