Refactor and patch only once

Author: staadecker

switch_model/utilities/load_data.py

@@ -1,35 +1,39 @@
+"""
+This file handles how data is loaded into SWITCH from the .csv files
+"""
 import os
-from typing import Type
 
 from pyomo.core.base.set import UnknownSetDimen
 from pyomo.environ import *
 
-# Mapping of file names to components to load from that file.
-# Ordered dict to ensure we are creating our components in the right order
+# Maps file names to Pyomo components.
+# The mapping indicates which components should be loaded with data from which files.
 _registered_components = {}
 
-def patch_to_allow_loading(cls: Type):
-    def new_init(self, *args, input_file=None, input_column=None, input_optional=None, **kwargs):
-        self.__old_init__(*args, **kwargs)
-        if input_file is None:
-            return
 
-        if input_optional is None:
-            input_optional = "default" in kwargs
-
-        self.input_column = input_column
-        self.input_optional = input_optional
+def register_component_for_loading(component, input_file, input_column, input_optional, **kwargs):
+    """
+    Adds a component to the mapping
+    """
+    # By default an input is optional if there is a default for that input already specified
+    if input_optional is None:
+        input_optional = "default" in kwargs
 
-        if input_file not in _registered_components:
-            _registered_components[input_file] = [self]
-        else:
-            _registered_components[input_file].append(self)
+    # Add the column and optional parameters to the component
+    component.input_column = input_column
+    component.input_optional = input_optional
 
-    cls.__old_init__ = cls.__init__
-    cls.__init__ = new_init
+    # Add the component to the mapping
+    if input_file not in _registered_components:
+        _registered_components[input_file] = [component]
+    else:
+        _registered_components[input_file].append(component)
 
 
 def load_registered_inputs(switch_data, inputs_dir):
+    """
+    Gets called to load all the inputs that are registered.
+    """
     for file, components in _registered_components.items():
         # We use lists since load_aug is going to convert to a list in any case
         params = [c for c in components if isinstance(c, Param)]
@@ -40,24 +44,25 @@ def load_registered_inputs(switch_data, inputs_dir):
             raise Exception(
                 "This should not happen. Did you specify an input file for an element that is not a Set or Param?")
 
-        kwargs = dict(filename=os.path.join(inputs_dir, file))
+        kwargs = {'filename': os.path.join(inputs_dir, file)}
 
         if len(index) > 1:
             raise Exception(f"Can't define multiple sets from the same file. {str(index)}")
         elif len(index) == 1:
             index = index[0]
-            optional = index.input_optional
+            optional = index.input_optional # entire file is optional if the index is optional
         else:
             index = None
-            optional = all(c.input_optional for c in components)
+            optional = all(c.input_optional for c in components) # file is optional if each param is optional and no index
 
         if len(params) == 0:
-            kwargs["set"] = index
+            kwargs["set"] = index  # when only defining the index, we must use 'set'
         else:
             kwargs["param"] = params
             if index is not None:
                 kwargs["index"] = index
 
+        # Load the data
         load_data(switch_data, optional=optional, auto_select=True, optional_params=optional_params, **kwargs)
 
     # Remove all the elements to reset the dictionary

switch_model/utilities/patches.py

@@ -1,13 +1,29 @@
 import inspect
 import textwrap
 import types
+from typing import Type
 
-import pyomo.version
-from pyomo.core.base.misc import _robust_sort_keyfcn
-
-from switch_model.utilities.load_data import patch_to_allow_loading
 from pyomo.environ import Set, Param
 
+from switch_model.utilities.load_data import register_component_for_loading
+
+_patched_pyomo = False
+
+def patch_pyomo():
+    global _patched_pyomo
+
+    if _patched_pyomo:
+        return
+
+    # fix Pyomo issue #2019. Once PR #2020 gets released this will no longer be needed
+    from pyomo.core.base.misc import _robust_sort_keyfcn
+    setattr(_robust_sort_keyfcn, "__call__", fixed_robust_sort_keyfcn)
+
+    # Patch Set and Param to allow specifying input file location (via input_file="...")
+    extend_to_allow_loading(Set)
+    extend_to_allow_loading(Param)
+
+    _patched_pyomo = True
 
 def fixed_robust_sort_keyfcn(self, val, use_key=True):
     """Generate a tuple ( str(type_name), val ) for sorting the value.
@@ -53,14 +69,15 @@ def fixed_robust_sort_keyfcn(self, val, use_key=True):
     else:
         return _typename, id(val)
 
-def patch_pyomo():
-    # fix Pyomo issue #2019. Once PR #2020 gets released this will no longer be needed
-    from pyomo.core.base.misc import _robust_sort_keyfcn
-    setattr(_robust_sort_keyfcn, "__call__", fixed_robust_sort_keyfcn)
+def extend_to_allow_loading(cls: Type):
+    def new_init(self, *args, input_file=None, input_column=None, input_optional=None, **kwargs):
+        self.__old_init__(*args, **kwargs)
+        if input_file is not None:
+            register_component_for_loading(self, input_file, input_column, input_optional, **kwargs)
+
+    cls.__old_init__ = cls.__init__
+    cls.__init__ = new_init
 
-    # Patch Set and Param to allow specifying input file location (via input_file="...")
-    patch_to_allow_loading(Set)
-    patch_to_allow_loading(Param)
 
 def replace_method(class_ref, method_name, new_source_code):
     """