Change setters list to dict

src/tdastro/base_models.py

@@ -21,17 +21,17 @@ class ParameterizedModel:
 
     Attributes
     ----------
-    setters : `list` of `tuple`
+    setters : `dict` of `tuple`
         A dictionary to information about the setters for the parameters in the form:
-        (name, ParameterSource, setter information, required). The attributes are
+        (ParameterSource, setter information, required). The attributes are
         stored in the order in which they need to be set.
     sample_iteration : `int`
         A counter used to syncronize  sampling runs. Tracks how many times this
         model's parameters have been resampled.
     """
 
     def __init__(self, **kwargs):
-        self.setters = []
+        self.setters = {}
         self.sample_iteration = 0
 
     def __str__(self):
@@ -63,11 +63,9 @@ def set_parameter(self, name, value=None, **kwargs):
         Raise a ``ValueError`` if the parameter is required, but set to None.
         """
         # Check for parameter has been added and if so, find the index.
-        try:
-            ind = next(ind for ind, entry in enumerate(self.setters) if entry[0] == name)
-        except StopIteration:
+        if name not in self.setters:
             raise KeyError(f"Tried to set parameter {name} that has not been added.") from None
-        required = self.setters[ind][3]
+        required = self.setters[name][2]
 
         if value is None and name in kwargs:
             # The value wasn't set, but the name is in kwargs.
@@ -76,26 +74,26 @@ def set_parameter(self, name, value=None, **kwargs):
         if value is not None:
             if isinstance(value, types.FunctionType):
                 # Case 1: If we are getting from a static function, sample it.
-                self.setters[ind] = (name, ParameterSource.FUNCTION, value, required)
+                self.setters[name] = (ParameterSource.FUNCTION, value, required)
                 setattr(self, name, value(**kwargs))
             elif isinstance(value, types.MethodType) and isinstance(value.__self__, ParameterizedModel):
                 # Case 2: We are trying to use the method from a ParameterizedModel.
                 # Note that this will (correctly) fail if we are adding a model method from the current
                 # object that requires an unset attribute.
-                self.setters[ind] = (name, ParameterSource.MODEL_METHOD, value, required)
+                self.setters[name] = (ParameterSource.MODEL_METHOD, value, required)
                 setattr(self, name, value(**kwargs))
             elif isinstance(value, ParameterizedModel):
                 # Case 3: We are trying to access an attribute from a parameterized model.
                 if not hasattr(value, name):
                     raise ValueError(f"Attribute {name} missing from parent.")
-                self.setters[ind] = (name, ParameterSource.MODEL_ATTRIBUTE, value, required)
+                self.setters[name] = (ParameterSource.MODEL_ATTRIBUTE, value, required)
                 setattr(self, name, getattr(value, name))
             else:
                 # Case 4: The value is constant.
-                self.setters[ind] = (name, ParameterSource.CONSTANT, value, required)
+                self.setters[name] = (ParameterSource.CONSTANT, value, required)
                 setattr(self, name, value)
         elif not required:
-            self.setters[ind] = (name, ParameterSource.CONSTANT, None, required)
+            self.setters[name] = (ParameterSource.CONSTANT, None, required)
             setattr(self, name, None)
         else:
             raise ValueError(f"Missing required parameter {name}")
@@ -134,7 +132,7 @@ def add_parameter(self, name, value=None, required=False, **kwargs):
 
         # Add an entry for the setter function and fill in the remaining
         # information using set_parameter().
-        self.setters.append((name, None, None, required))
+        self.setters[name] = (None, None, required)
         self.set_parameter(name, value, **kwargs)
 
     def sample_parameters(self, max_depth=50, **kwargs):
@@ -159,7 +157,9 @@ def sample_parameters(self, max_depth=50, **kwargs):
             raise ValueError(f"Maximum sampling depth exceeded at {self}. Potential infinite loop.")
 
         # Run through each parameter and sample it based on the given recipe.
-        for name, source_type, setter, _ in self.setters:
+        # As of Python 3.7 dictionaries are guaranteed to preserve insertion ordering,
+        # so this will iterate through attributes in the order they were inserted.
+        for name, (source_type, setter, _) in self.setters.items():
             sampled_value = None
             if source_type == ParameterSource.CONSTANT:
                 sampled_value = setter