Add function to read all ENDF evaluations from a single file

docs/source/pythonapi/index.rst

@@ -478,6 +478,7 @@ Functions
 
     openmc.data.endf.float_endf
     openmc.data.endf.get_cont_record
+    openmc.data.endf.get_evaluations
     openmc.data.endf.get_head_record
     openmc.data.endf.get_tab1_record
     openmc.data.endf.get_tab2_record

openmc/data/endf.py

@@ -14,6 +14,7 @@ import os
 from math import pi
 from collections import OrderedDict, Iterable
 
+from six import string_types
 import numpy as np
 from numpy.polynomial.polynomial import Polynomial
 
@@ -249,14 +250,40 @@ def get_tab2_record(file_obj):
 
     return params, Tabulated2D(breakpoints, interpolation)
 
+def get_evaluations(filename):
+    """Return a list of all evaluations within an ENDF file.
+
+    Parameters
+    ----------
+    filename : str
+        Path to ENDF-6 formatted file
+
+    Returns
+    -------
+    list
+        A list of :class:`openmc.data.endf.Evaluation` instances.
+
+    """
+    evaluations = []
+    with open(filename, 'r') as fh:
+        while True:
+            pos = fh.tell()
+            line = fh.readline()
+            if line[66:70] == '  -1':
+                break
+            fh.seek(pos)
+            evaluations.append(Evaluation(fh))
+    return evaluations
+
 
 class Evaluation(object):
     """ENDF material evaluation with multiple files/sections
 
     Parameters
     ----------
-    filename : str
-        Path to ENDF file to read
+    filename_or_obj : str or file-like
+        Path to ENDF file to read or an open file positioned at the start of an
+        ENDF material
 
     Attributes
     ----------
@@ -273,8 +300,11 @@ class Evaluation(object):
         indicator (MOD).
 
     """
-    def __init__(self, filename):
-        fh = open(filename, 'r')
+    def __init__(self, filename_or_obj):
+        if isinstance(filename_or_obj, string_types):
+            fh = open(filename_or_obj, 'r')
+        else:
+            fh = filename_or_obj
         self.section = {}
         self.info = {}
         self.target = {}
@@ -304,6 +334,7 @@ class Evaluation(object):
 
             # If end of material reached, exit loop
             if MAT == 0:
+                fh.readline()
                 break
 
             section_data = ''