1 files changed, 24 insertions, 20 deletions

diff --git a/polymatrix/expression/mixins/linearinexprmixin.py b/polymatrix/expression/mixins/linearinexprmixin.py
index a900b7f..8354754 100644
--- a/polymatrix/expression/mixins/linearinexprmixin.py
+++ b/polymatrix/expression/mixins/linearinexprmixin.py
@@ -1,4 +1,3 @@
-
 import abc
 import collections
 
@@ -7,7 +6,9 @@ from polymatrix.expression.mixins.expressionbasemixin import ExpressionBaseMixin
 from polymatrix.polymatrix.abc import PolyMatrix
 from polymatrix.expressionstate.abc import ExpressionState
 from polymatrix.expression.utils.getmonomialindices import get_monomial_indices
-from polymatrix.expression.utils.getvariableindices import get_variable_indices_from_variable
+from polymatrix.expression.utils.getvariableindices import (
+    get_variable_indices_from_variable,
+)
 
 
 class LinearInExprMixin(ExpressionBaseMixin):
@@ -33,48 +34,51 @@ class LinearInExprMixin(ExpressionBaseMixin):
 
     @property
     @abc.abstractmethod
-    def underlying(self) -> ExpressionBaseMixin:
-        ...
+    def underlying(self) -> ExpressionBaseMixin: ...
 
     @property
     @abc.abstractmethod
-    def monomials(self) -> ExpressionBaseMixin:
-        ...
+    def monomials(self) -> ExpressionBaseMixin: ...
 
     @property
     @abc.abstractmethod
-    def variables(self) -> ExpressionBaseMixin:
-        ...
+    def variables(self) -> ExpressionBaseMixin: ...
 
     @property
     @abc.abstractmethod
-    def ignore_unmatched(self) -> bool:
-        ...
+    def ignore_unmatched(self) -> bool: ...
 
     # overwrites the abstract method of `ExpressionBaseMixin`
     def apply(
-        self, 
+        self,
         state: ExpressionState,
     ) -> tuple[ExpressionState, PolyMatrix]:
-    
         state, underlying = self.underlying.apply(state=state)
         state, monomials = get_monomial_indices(state, self.monomials)
-        state, variable_indices = get_variable_indices_from_variable(state, self.variables)
+        state, variable_indices = get_variable_indices_from_variable(
+            state, self.variables
+        )
 
         assert underlying.shape[1] == 1
 
         poly_matrix_data = collections.defaultdict(dict)
 
         for row in range(underlying.shape[0]):
-
             polynomial = underlying.get_poly(row, 0)
             if polynomial is None:
                 continue
 
             for monomial, value in polynomial.items():
-
-                x_monomial = tuple((var_idx, count) for var_idx, count in monomial if var_idx in variable_indices)
-                p_monomial = tuple((var_idx, count) for var_idx, count in monomial if var_idx not in variable_indices)
+                x_monomial = tuple(
+                    (var_idx, count)
+                    for var_idx, count in monomial
+                    if var_idx in variable_indices
+                )
+                p_monomial = tuple(
+                    (var_idx, count)
+                    for var_idx, count in monomial
+                    if var_idx not in variable_indices
+                )
 
                 try:
                     col = monomials.index(x_monomial)
@@ -82,13 +86,13 @@ class LinearInExprMixin(ExpressionBaseMixin):
                     if self.ignore_unmatched:
                         continue
                     else:
-                        raise Exception(f'{x_monomial} not in {monomials}')
+                        raise Exception(f"{x_monomial} not in {monomials}")
 
                 poly_matrix_data[row, col][p_monomial] = value
-        
+
         poly_matrix = init_poly_matrix(
             data=dict(poly_matrix_data),
             shape=(underlying.shape[0], len(monomials)),
         )
 
-        return state, poly_matrix   
+        return state, poly_matrix