Change signatures of _constrained_ordination helper functions

- Changed first argument to be positional, rather than required keyword
- Edit error message to return list rather than dict_keys

src/sknnr/transformers/_constrained_ordination.py

@@ -6,12 +6,12 @@
 from numpy.typing import NDArray
 
 
-def is_2d_numeric_array(*, arr: NDArray) -> bool:
+def is_2d_numeric_array(arr: NDArray) -> bool:
     """Verify that arr is a 2D numeric array."""
     return arr.ndim == 2 and np.issubdtype(arr.dtype, np.number)
 
 
-def zero_sum_vectors(*, arr: NDArray, axis: int) -> NDArray:
+def zero_sum_vectors(arr: NDArray, *, axis: int) -> NDArray:
     """Find any rows or columns in arr that sum to 0."""
     return arr.sum(axis=axis) <= 0.0
 
@@ -44,19 +44,19 @@ def _set_initialization_attributes(self, X: NDArray, Y: NDArray) -> None:
     @staticmethod
     def _check_inputs(X: NDArray, Y: NDArray) -> tuple[NDArray, NDArray]:
         """Verify that X and Y are valid inputs in preparation for ordination."""
-        if not is_2d_numeric_array(arr=X):
+        if not is_2d_numeric_array(X):
             raise ValueError("X must be a 2D numeric numpy array")
 
-        if not is_2d_numeric_array(arr=Y):
+        if not is_2d_numeric_array(Y):
             raise ValueError("Y must be a 2D numeric numpy array")
 
         if X.shape[0] != Y.shape[0]:
             raise ValueError("X and Y must have the same number of rows")
 
-        if np.any(zero_sum_vectors(arr=X, axis=1)):
+        if np.any(zero_sum_vectors(X, axis=1)):
             raise ValueError("All row sums in X must be greater than 0")
 
-        excluded_columns = zero_sum_vectors(arr=Y, axis=0)
+        excluded_columns = zero_sum_vectors(Y, axis=0)
         return X, Y[:, ~excluded_columns]
 
     @property

src/sknnr/transformers/_constrained_transformer.py

@@ -36,7 +36,7 @@ def fit(self, X, y):
         method_cls = self.CONSTRAINED_METHODS.get(self.constrained_method)
         if method_cls is None:
             raise ValueError(
-                f"`method` must be one of {self.CONSTRAINED_METHODS.keys()}, not"
+                f"`method` must be one of {list(self.CONSTRAINED_METHODS.keys())}, not"
                 f" {self.constrained_method}."
             )
         self.ordination_ = method_cls(X, y)