use OrderedDict for process variables and meta (consistent repr)

xsimlab/process.py

@@ -1,6 +1,7 @@
 import sys
 import inspect
 import copy
+from collections import OrderedDict
 
 from .variable.base import (AbstractVariable, DiagnosticVariable,
                             VariableList, VariableGroup)
@@ -76,12 +77,12 @@ def __new__(cls, name, bases, attrs):
                 )
             meta_dict.update(meta_attrs)
 
-        new_attrs['_meta'] = meta_dict
+        new_attrs['_meta'] = OrderedDict(sorted(meta_dict.items()))
 
         # add variables and diagnostics separately from the rest of
         # the attributes and methods defined in the class
         vars, novars = _extract_variables(attrs)
-        new_attrs['_variables'] = vars
+        new_attrs['_variables'] = OrderedDict(sorted(vars.items()))
         for k, v in novars.items():
             new_attrs[k] = v
 

xsimlab/tests/test_process.py

@@ -50,12 +50,12 @@ def setUp(self):
         self.my_process = MyProcess()
         self.my_process_str = dedent("""\
         Variables:
+          * diag       DiagnosticVariable
           * var        Variable ()
+            var_group  VariableGroup 'group'
             var_list   VariableList
             -          Variable ('x')
             -          Variable (), ('x')
-            var_group  VariableGroup 'group'
-          * diag       DiagnosticVariable
         Meta:
             time_dependent: False""")