Consistency in treatment of paths for files specified within the Mode…

…l class (#3153)

docs/source/usersguide/geometry.rst

@@ -474,7 +474,7 @@ applied as universes in the OpenMC geometry file. A geometry represented
 entirely by a DAGMC geometry will contain only the DAGMC universe. Using a
 :class:`openmc.DAGMCUniverse` looks like the following::
 
-   dag_univ = openmc.DAGMCUniverse(filename='dagmc.h5m')
+   dag_univ = openmc.DAGMCUniverse('dagmc.h5m')
    geometry = openmc.Geometry(dag_univ)
    geometry.export_to_xml()
 
@@ -495,13 +495,22 @@ It is important in these cases to understand the DAGMC model's position
 with respect to the CSG geometry. DAGMC geometries can be plotted with
 OpenMC to verify that the model matches one's expectations.
 
-**Note:** DAGMC geometries used in OpenMC are currently required to be clean,
-meaning that all surfaces have been `imprinted and merged
-<https://svalinn.github.io/DAGMC/usersguide/cubit_basics.html>`_ successfully
-and that the model is `watertight
-<https://svalinn.github.io/DAGMC/usersguide/tools.html#make-watertight>`_.
-Future implementations of DAGMC geometry will support small volume overlaps and
-un-merged surfaces.
+By default, when you specify a .h5m file for a :class:`~openmc.DAGMCUniverse`
+instance, it will store the absolute path to the .h5m file. If you prefer to
+store the relative path, you can set the ``'resolve_paths'`` configuration
+variable::
+
+  openmc.config['resolve_paths'] = False
+  dag_univ = openmc.DAGMCUniverse('dagmc.h5m')
+
+.. note::
+    DAGMC geometries used in OpenMC are currently required to be clean,
+    meaning that all surfaces have been `imprinted and merged
+    <https://svalinn.github.io/DAGMC/usersguide/cubit_basics.html>`_ successfully
+    and that the model is `watertight
+    <https://svalinn.github.io/DAGMC/usersguide/tools.html#make-watertight>`_.
+    Future implementations of DAGMC geometry will support small volume overlaps and
+    un-merged surfaces.
 
 Cell, Surface, and Material IDs
 -------------------------------

openmc/config.py

@@ -1,4 +1,5 @@
 from collections.abc import MutableMapping
+from contextlib import contextmanager
 import os
 from pathlib import Path
 import warnings
@@ -11,7 +12,7 @@
 
 class _Config(MutableMapping):
     def __init__(self, data=()):
-        self._mapping = {}
+        self._mapping = {'resolve_paths': True}
         self.update(data)
 
     def __getitem__(self, key):
@@ -42,10 +43,12 @@ def __setitem__(self, key, value):
             # Reset photon source data since it relies on chain file
             _DECAY_PHOTON_ENERGY.clear()
             _DECAY_ENERGY.clear()
+        elif key == 'resolve_paths':
+            self._mapping[key] = value
         else:
             raise KeyError(f'Unrecognized config key: {key}. Acceptable keys '
-                           'are "cross_sections", "mg_cross_sections" and '
-                           '"chain_file"')
+                           'are "cross_sections", "mg_cross_sections", '
+                           '"chain_file", and "resolve_paths".')
 
     def __iter__(self):
         return iter(self._mapping)
@@ -61,6 +64,24 @@ def _set_path(self, key, value):
         if not p.exists():
             warnings.warn(f"'{value}' does not exist.")
 
+    @contextmanager
+    def patch(self, key, value):
+        """Temporarily change a value in the configuration.
+
+        Parameters
+        ----------
+        key : str
+            Key to change
+        value : object
+            New value
+        """
+        previous_value = self.get(key)
+        self[key] = value
+        yield
+        if previous_value is None:
+            del self[key]
+        else:
+            self[key] = previous_value
 
 def _default_config():
     """Return default configuration"""

openmc/material.py

@@ -16,6 +16,7 @@
 import openmc.checkvalue as cv
 from ._xml import clean_indentation, reorder_attributes
 from .mixin import IDManagerMixin
+from .utility_funcs import input_path
 from openmc.checkvalue import PathLike
 from openmc.stats import Univariate, Discrete, Mixture
 from openmc.data.data import _get_element_symbol
@@ -1643,7 +1644,7 @@ def cross_sections(self) -> Path | None:
     @cross_sections.setter
     def cross_sections(self, cross_sections):
         if cross_sections is not None:
-            self._cross_sections = Path(cross_sections)
+            self._cross_sections = input_path(cross_sections)
 
     def append(self, material):
         """Append material to collection

openmc/mesh.py

@@ -5,8 +5,6 @@
 from functools import wraps
 from math import pi, sqrt, atan2
 from numbers import Integral, Real
-from pathlib import Path
-import tempfile
 
 import h5py
 import lxml.etree as ET
@@ -19,6 +17,7 @@
 from ._xml import get_text
 from .mixin import IDManagerMixin
 from .surface import _BOUNDARY_TYPES
+from .utility_funcs import input_path
 
 
 class MeshBase(IDManagerMixin, ABC):
@@ -2072,7 +2071,7 @@ class UnstructuredMesh(MeshBase):
 
     Parameters
     ----------
-    filename : str or pathlib.Path
+    filename : path-like
         Location of the unstructured mesh file
     library : {'moab', 'libmesh'}
         Mesh library used for the unstructured mesh tally
@@ -2158,8 +2157,8 @@ def filename(self):
 
     @filename.setter
     def filename(self, filename):
-        cv.check_type('Unstructured Mesh filename', filename, (str, Path))
-        self._filename = filename
+        cv.check_type('Unstructured Mesh filename', filename, PathLike)
+        self._filename = input_path(filename)
 
     @property
     def library(self):

openmc/settings.py

@@ -8,12 +8,14 @@
 import lxml.etree as ET
 
 import openmc.checkvalue as cv
+from openmc.checkvalue import PathLike
 from openmc.stats.multivariate import MeshSpatial
-from . import (RegularMesh, SourceBase, MeshSource, IndependentSource,
-               VolumeCalculation, WeightWindows, WeightWindowGenerator)
 from ._xml import clean_indentation, get_text, reorder_attributes
-from openmc.checkvalue import PathLike
-from .mesh import _read_meshes
+from .mesh import _read_meshes, RegularMesh
+from .source import SourceBase, MeshSource, IndependentSource
+from .utility_funcs import input_path
+from .volume import VolumeCalculation
+from .weight_windows import WeightWindows, WeightWindowGenerator
 
 
 class RunMode(Enum):
@@ -699,14 +701,18 @@ def surf_source_read(self) -> dict:
         return self._surf_source_read
 
     @surf_source_read.setter
-    def surf_source_read(self, surf_source_read: dict):
-        cv.check_type('surface source reading options', surf_source_read, Mapping)
-        for key, value in surf_source_read.items():
+    def surf_source_read(self, ssr: dict):
+        cv.check_type('surface source reading options', ssr, Mapping)
+        for key, value in ssr.items():
             cv.check_value('surface source reading key', key,
                            ('path'))
             if key == 'path':
-                cv.check_type('path to surface source file', value, str)
-        self._surf_source_read = surf_source_read
+                cv.check_type('path to surface source file', value, PathLike)
+        self._surf_source_read = dict(ssr)
+
+        # Resolve path to surface source file
+        if 'path' in ssr:
+            self._surf_source_read['path'] = input_path(ssr['path'])
 
     @property
     def surf_source_write(self) -> dict:
@@ -1066,8 +1072,8 @@ def weight_windows_file(self) -> PathLike | None:
 
     @weight_windows_file.setter
     def weight_windows_file(self, value: PathLike):
-        cv.check_type('weight windows file', value, (str, Path))
-        self._weight_windows_file = value
+        cv.check_type('weight windows file', value, PathLike)
+        self._weight_windows_file = input_path(value)
 
     @property
     def weight_window_generators(self) -> list[WeightWindowGenerator]:
@@ -1241,7 +1247,7 @@ def _create_surf_source_read_subelement(self, root):
             element = ET.SubElement(root, "surf_source_read")
             if 'path' in self._surf_source_read:
                 subelement = ET.SubElement(element, "path")
-                subelement.text = self._surf_source_read['path']
+                subelement.text = str(self._surf_source_read['path'])
 
     def _create_surf_source_write_subelement(self, root):
         if self._surf_source_write:
@@ -1501,7 +1507,7 @@ def _create_weight_window_generators_subelement(self, root, mesh_memo=None):
     def _create_weight_windows_file_element(self, root):
         if self.weight_windows_file is not None:
             element = ET.Element("weight_windows_file")
-            element.text = self.weight_windows_file
+            element.text = str(self.weight_windows_file)
             root.append(element)
 
     def _create_weight_window_checkpoints_subelement(self, root):
@@ -1645,9 +1651,11 @@ def _sourcepoint_from_xml_element(self, root):
     def _surf_source_read_from_xml_element(self, root):
         elem = root.find('surf_source_read')
         if elem is not None:
+            ssr = {}
             value = get_text(elem, 'path')
             if value is not None:
-                self.surf_source_read['path'] = value
+                ssr['path'] = value
+            self.surf_source_read = ssr
 
     def _surf_source_write_from_xml_element(self, root):
         elem = root.find('surf_source_write')

openmc/source.py

@@ -3,6 +3,7 @@
 from collections.abc import Iterable, Sequence
 from enum import IntEnum
 from numbers import Real
+from pathlib import Path
 import warnings
 from typing import Any
 from pathlib import Path
@@ -19,6 +20,7 @@
 from openmc.stats.univariate import Univariate
 from ._xml import get_text
 from .mesh import MeshBase, StructuredMesh, UnstructuredMesh
+from .utility_funcs import input_path
 
 
 class SourceBase(ABC):
@@ -664,7 +666,7 @@ class CompiledSource(SourceBase):
 
     Parameters
     ----------
-    library : str or None
+    library : path-like
         Path to a compiled shared library
     parameters : str
         Parameters to be provided to the compiled shared library function
@@ -686,7 +688,7 @@ class CompiledSource(SourceBase):
 
     Attributes
     ----------
-    library : str or None
+    library : pathlib.Path
         Path to a compiled shared library
     parameters : str
         Parameters to be provided to the compiled shared library function
@@ -702,17 +704,13 @@ class CompiledSource(SourceBase):
     """
     def __init__(
         self,
-        library: str | None  = None,
+        library: PathLike,
         parameters: str | None = None,
         strength: float = 1.0,
         constraints: dict[str, Any] | None = None
     ) -> None:
         super().__init__(strength=strength, constraints=constraints)
-
-        self._library = None
-        if library is not None:
-            self.library = library
-
+        self.library = library
         self._parameters = None
         if parameters is not None:
             self.parameters = parameters
@@ -722,13 +720,13 @@ def type(self) -> str:
         return "compiled"
 
     @property
-    def library(self) -> str:
+    def library(self) -> Path:
         return self._library
 
     @library.setter
-    def library(self, library_name):
-        cv.check_type('library', library_name, str)
-        self._library = library_name
+    def library(self, library_name: PathLike):
+        cv.check_type('library', library_name, PathLike)
+        self._library = input_path(library_name)
 
     @property
     def parameters(self) -> str:
@@ -748,7 +746,7 @@ def populate_xml_element(self, element):
             XML element containing source data
 
         """
-        element.set("library", self.library)
+        element.set("library", str(self.library))
 
         if self.parameters is not None:
             element.set("parameters", self.parameters)
@@ -794,7 +792,7 @@ class FileSource(SourceBase):
 
     Parameters
     ----------
-    path : str or pathlib.Path
+    path : path-like
         Path to the source file from which sites should be sampled
     strength : float
         Strength of the source (default is 1.0)
@@ -829,14 +827,12 @@ class FileSource(SourceBase):
 
     def __init__(
         self,
-        path: PathLike | None = None,
+        path: PathLike,
         strength: float = 1.0,
         constraints: dict[str, Any] | None = None
     ):
         super().__init__(strength=strength, constraints=constraints)
-        self._path = None
-        if path is not None:
-            self.path = path
+        self.path = path
 
     @property
     def type(self) -> str:
@@ -848,8 +844,8 @@ def path(self) -> PathLike:
 
     @path.setter
     def path(self, p: PathLike):
-        cv.check_type('source file', p, str)
-        self._path = p
+        cv.check_type('source file', p, PathLike)
+        self._path = input_path(p)
 
     def populate_xml_element(self, element):
         """Add necessary file source information to an XML element
@@ -861,7 +857,7 @@ def populate_xml_element(self, element):
 
         """
         if self.path is not None:
-            element.set("file", self.path)
+            element.set("file", str(self.path))
 
     @classmethod
     def from_xml_element(cls, elem: ET.Element) -> openmc.FileSource: