gh-39056: miscellanous pep8 cleanup
    
in various places

### 📝 Checklist

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
    
URL: #39056
Reported by: Frédéric Chapoton
Reviewer(s): gmou3

Author: Release Manager

src/sage/matrix/matrix_misc.py

@@ -14,8 +14,8 @@
 #
 #  The full text of the GPL is available at:
 #
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from sage.categories.fields import Fields
 _Fields = Fields()
@@ -309,4 +309,4 @@ def permanental_minor_polynomial(A, permanent_only=False, var='t', prec=None):
                            " algorithm... please contact [email protected]")
 
     p = p[0]
-    return p[min(nrows,ncols)] if permanent_only else p
+    return p[min(nrows, ncols)] if permanent_only else p

src/sage/matroids/chow_ring.py

@@ -11,6 +11,7 @@
 from sage.categories.graded_algebras_with_basis import GradedAlgebrasWithBasis
 from sage.categories.commutative_rings import CommutativeRings
 
+
 class ChowRing(QuotientRing_generic):
     r"""
     The Chow ring of a matroid.
@@ -336,4 +337,4 @@ def homogeneous_degree(self):
             f = self.lift()
             if not f.is_homogeneous():
                 raise ValueError("element is not homogeneous")
-            return f.degree()
+            return f.degree()

src/sage/matroids/constructor.py

@@ -805,11 +805,11 @@ def Matroid(groundset=None, data=None, **kwds):
         if isinstance(data, Graph):
             key = 'graph'
         elif isinstance(data, Matrix) or (
-             isinstance(data, tuple) and isinstance(data[0], Matrix)):
+                isinstance(data, tuple) and isinstance(data[0], Matrix)):
             key = 'matrix'
         elif isinstance(data, sage.modules.with_basis.morphism.ModuleMorphism) or (
-             isinstance(data, tuple) and
-             isinstance(data[0], sage.modules.with_basis.morphism.ModuleMorphism)):
+                isinstance(data, tuple) and
+                isinstance(data[0], sage.modules.with_basis.morphism.ModuleMorphism)):
             key = 'morphism'
         elif isinstance(data, sage.matroids.matroid.Matroid):
             key = 'matroid'
@@ -1032,11 +1032,9 @@ def revlex_sort_key(s):
         subsets = sorted(combinations(range(N), rk), key=revlex_sort_key)
         if len(data) != len(subsets):
             raise ValueError("expected string of length %s (%s choose %s), got %s" %
-                (len(subsets), N, rk, len(data)))
-        bases = []
-        for i, x in enumerate(data):
-            if x != '0':
-                bases.append([groundset[c] for c in subsets[i]])
+                             (len(subsets), N, rk, len(data)))
+        bases = [[groundset[c] for c in subsets[i]]
+                 for i, x in enumerate(data) if x != '0']
         M = BasisMatroid(groundset=groundset, bases=bases)
 
     # Circuit closures:

src/sage/modules/free_quadratic_module_integer_symmetric.py

@@ -1556,19 +1556,20 @@ def _fplll_enumerate(self, target=None):
         gmat = fpylll.IntegerMatrix(dim, dim)
         for i in range(dim):
             for j in range(dim):
-                gmat[i,j] = gram[i,j]
+                gmat[i, j] = gram[i, j]
         gso = fpylll.GSO.Mat(gmat, gram=True)
         ok = gso.update_gso()
         assert ok
 
         coord = None
         if target is not None:
             coord = basis.solve_left(target)
-            Mu = 1 + matrix([gso.get_mu(i,j) for j in range(dim)] for i in range(dim))
+            Mu = 1 + matrix([gso.get_mu(i, j) for j in range(dim)]
+                            for i in range(dim))
             coord *= Mu
 
         count = 8
-        bound = gso.get_r(dim-1, dim-1)
+        bound = gso.get_r(dim - 1, dim - 1)
         seen = set()
         while True:
             enum = fpylll.Enumeration(gso, count, fpylll.EvaluatorStrategy.BEST_N_SOLUTIONS)
@@ -1579,8 +1580,8 @@ def _fplll_enumerate(self, target=None):
             if len(combs) < count:
                 bound *= 2
                 continue
-            for length,comb in combs:
-                vec = sum(ZZ(c)*b for c,b in zip(comb,basis))
+            for length, comb in combs:
+                vec = sum(ZZ(c) * b for c, b in zip(comb, basis))
                 if tuple(vec) not in seen:
                     yield vec
                     seen.add(tuple(vec))

src/sage/quadratic_forms/all.py

@@ -6,13 +6,17 @@
 
 from sage.quadratic_forms.quadratic_form import QuadraticForm, DiagonalQuadraticForm, quadratic_form_from_invariants
 
-from sage.quadratic_forms.random_quadraticform import (random_quadraticform, random_quadraticform_with_conditions,
-                                   random_ternaryqf, random_ternaryqf_with_conditions)
+from sage.quadratic_forms.random_quadraticform import (random_quadraticform,
+                                                       random_quadraticform_with_conditions,
+                                                       random_ternaryqf,
+                                                       random_ternaryqf_with_conditions)
 
 from sage.quadratic_forms.extras import least_quadratic_nonresidue, extend_to_primitive, is_triangular_number
 
-from sage.quadratic_forms.special_values import (gamma__exact, zeta__exact, QuadraticBernoulliNumber,
-                             quadratic_L_function__exact, quadratic_L_function__numerical)
+from sage.quadratic_forms.special_values import (gamma__exact, zeta__exact,
+                                                 QuadraticBernoulliNumber,
+                                                 quadratic_L_function__exact,
+                                                 quadratic_L_function__numerical)
 
 from sage.quadratic_forms.genera.genus import Genus
 

src/sage/quadratic_forms/quadratic_form__local_density_congruence.py

@@ -291,7 +291,7 @@ def local_good_density_congruence_even(self, m, Zvec, NZvec):
     # Take cases on the existence of additional nonzero congruence conditions (mod 2)
     if NZvec is None:
         total = (4 ** len(Z_Is8)) * (8 ** len(Is8_minus_Z)) \
-            * count_all_local_good_types_normal_form(Q_Not8,2, 3, m, list(Z_Not8), None)
+            * count_all_local_good_types_normal_form(Q_Not8, 2, 3, m, list(Z_Not8), None)
     else:
         ZNZ = Z + Set(NZvec)
         ZNZ_Not8 = Not8.intersection(ZNZ)

src/sage/quivers/ar_quiver.py

@@ -9,8 +9,8 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from sage.structure.unique_representation import UniqueRepresentation
 from sage.structure.parent import Parent