Merge pull request #47 from KingsburyLab/sort

Solution: always sort components by amount

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- `Solution.components` is now automatically sorted in descending order of amount, for
+  consistency with `anions`, `cations`, and `neutrals`.
+
 ### Fixed
 
 - Bugfix in `as_dict` to make serialization via `dumpfn` possible. Previously, `Quantity`

src/pyEQL/solution.py

@@ -495,26 +495,23 @@ def cations(self) -> dict[str, float]:
         Returns the subset of `components` {formula: moles} that are cations. The returned dict is sorted by
         amount in descending order.
         """
-        d = {k: v for k, v in self.components.items() if self.get_property(k, "charge") > 0}
-        return dict(sorted(d.items(), key=lambda x: x[1], reverse=True))
+        return {k: v for k, v in self.components.items() if self.get_property(k, "charge") > 0}
 
     @property
     def anions(self) -> dict[str, float]:
         """
         Returns the subset of `components` {formula: moles} that are anions. The returned dict is sorted by
         amount in descending order.
         """
-        d = {k: v for k, v in self.components.items() if self.get_property(k, "charge") < 0}
-        return dict(sorted(d.items(), key=lambda x: x[1], reverse=True))
+        return {k: v for k, v in self.components.items() if self.get_property(k, "charge") < 0}
 
     @property
     def neutrals(self) -> dict[str, float]:
         """
         Returns the subset of `components` {formula: moles} that are neutral (not charged). The returned dict is sorted by
         amount in descending order.
         """
-        d = {k: v for k, v in self.components.items() if self.get_property(k, "charge") == 0}
-        return dict(sorted(d.items(), key=lambda x: x[1], reverse=True))
+        return {k: v for k, v in self.components.items() if self.get_property(k, "charge") == 0}
 
     # TODO - need tests for viscosity
     @property
@@ -1113,8 +1110,7 @@ def get_components_by_element(self) -> dict[str, list]:
         d = {}
         # by sorting the components according to amount, we ensure that the species
         # are sorted in descending order of concentration in the resulting dict
-        components = dict(sorted(self.components.items(), key=lambda x: x[1], reverse=True))
-        for s in components:
+        for s in self.components:
             # determine the element and oxidation state
             elements = self.get_property(s, "elements")
 

src/pyEQL/utils.py

@@ -45,6 +45,8 @@ def __getitem__(self, key):
 
     def __setitem__(self, key, value):
         super().__setitem__(standardize_formula(key), value)
+        # sort contents anytime an item is set
+        self.data = dict(sorted(self.items(), key=lambda x: x[1], reverse=True))
 
     def __delitem__(self, key):
         super().__delitem__(standardize_formula(key))