remove some unused variables

src/sage/algebras/down_up_algebra.py

@@ -806,7 +806,6 @@ def is_weight_vector(self):
 
             P = self.parent()
             R = P.base_ring()
-            weights = P._weights
 
             def get_wt(n):
                 if not n:
@@ -853,9 +852,8 @@ def weight(self):
             P = self.parent()
             R = P.base_ring()
             V = FreeModule(R, 2)
-            weights = P._weights
             it = iter(self._monomial_coefficients)
             n = next(it)
             if not n:
                 return V([P._weights[0], R.zero()])
-            return V([P._weights[n], P._weights[n-1]])
+            return V([P._weights[n], P._weights[n - 1]])

src/sage/algebras/lie_algebras/affine_lie_algebra.py

@@ -838,10 +838,9 @@ def _test_classical_subalgebra(self, **options):
         tester = self._tester(**options)
         B = self.basis()
         roots = set(self._g._Q.roots())
-        ac = list(self._g._Q.simple_coroots())
         from sage.misc.misc import some_tuples
         for r, s in some_tuples(roots, 2, tester._max_runs):
-            ret = B[r,0].bracket(B[s,0])
+            ret = B[r, 0].bracket(B[s, 0])
             if r + s in roots:
                 tester.assertEqual(list(ret.support()), [(r+s, 0)], f"obtained [{r}, {s}] == {ret}")
             elif r == -s:
@@ -1125,7 +1124,6 @@ def __init__(self, cartan_type):
             Q = finite_ct.relabel({n-i: i for i in range(n)}).root_system().root_lattice()
             self._roots = tuple(Q.roots())
             self._ac = tuple(Q.simple_coroots())
-            CP = cartesian_product([range(3)] * n)
             if cartan_type.rank() == 2:
                 self._short_roots = self._roots + tuple(2*r for r in Q.roots())
             else:
@@ -1200,7 +1198,6 @@ def __iter__(self):
             finite_ct = finite_ct.relabel({n-i: i for i in range(n)})
         else:
             finite_ct = self._cartan_type.classical()
-        Q = finite_ct.root_system().root_lattice()
         P = self._facade_for[0]
         for i in ZZ:
             if i % 2:

src/sage/algebras/lie_algebras/center_uea.py

@@ -419,7 +419,6 @@ def __iter__(self):
         n = len(self._gen_degrees)
         wts = sorted(self._gen_degrees.values(), reverse=True)
         while True:
-            total = 0
             for exps in intvecwt_iterator(deg, wts):
                 yield self.element_class(self, {n-1-i: e for i, e in enumerate(exps) if e})
             deg += 1

src/sage/algebras/lie_algebras/classical_lie_algebra.py

@@ -941,7 +941,7 @@
             sage: g
             Simple matrix Lie algebra of type ['E', 7] over Rational Field
 
             sage: len(g.basis())  # long time
             133
             sage: TestSuite(g).run()  # long time
         """
@@ -2359,7 +2359,6 @@
                                    for ii, ca in r._monomial_coefficients.items()
                                    for jj, cb in s._monomial_coefficients.items())
                     s_coeffs[r, s] = {r+s: coeff}
-                    ht = sum(r.coefficients()) + sum(s.coefficients())
                     s_coeffs[-r, -s] = {-r-s: -coeff}
                 if r - s in p_roots_set or s - r in p_roots_set:
                     coeff = R.prod((-1)**(ca*cb) if (ii, jj) in self._epsilon or ii == jj else 1

src/sage/categories/filtered_modules_with_basis.py

@@ -1197,7 +1197,6 @@ def hilbert_series(self, prec=None):
                 from collections import defaultdict
                 from sage.rings.integer_ring import ZZ
                 from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
-                R = self.base_ring()
                 PR = PolynomialRing(ZZ, 't')
                 dims = defaultdict(ZZ)
                 for b in self.basis():

src/sage/categories/finite_dimensional_algebras_with_basis.py

@@ -207,7 +207,6 @@ def root_fcn(s, x):
                 s = 1
                 n = self.dimension()
                 B = [b.on_left_matrix() for b in self.basis()]
-                I = B[0].parent().one()
                 while s <= n:
                     # we use that p_{AB}(x) = p_{BA}(x) here
                     data = [[None]*(len(B)+1) for _ in B]

src/sage/categories/finite_dimensional_lie_algebras_with_basis.py

@@ -605,13 +605,13 @@ def normalizer_basis(self, S):
                 sc[k[1], k[0]] = -v
             X = self.basis().keys()
             d = len(X)
-            ret = []
             t = m.nrows()
             c_mat = matrix(self.base_ring(),
-                           [[sum(m[i,j] * sc[x,xp][k] for j, xp in enumerate(X)
-                                 if (x, xp) in sc)
+                           [[sum(m[i, j] * sc[x, xp][k]
+                                 for j, xp in enumerate(X) if (x, xp) in sc)
                              for x in X]
-                            + [0]*(i*t) + [-m[j,k] for j in range(t)] + [0]*((t-i-1)*t)
+                            + [0]*(i*t) + [-m[j, k] for j in range(t)]
+                            + [0]*((t-i-1)*t)
                             for i in range(t) for k in range(d)])
             C = c_mat.right_kernel().basis_matrix()
             return [self.from_vector(c[:d]) for c in C]

src/sage/categories/simplicial_sets.py

@@ -499,7 +499,6 @@ def covering_map(self, character):
                             for g in G:
                                 cell = AbstractSimplex(d, name="({}, {})".format(s, g))
                                 cells_dict[(s, g)] = cell
-                                fd = []
                                 faces = self.faces(s)
                                 f0 = faces[0]
                                 for h in G:
@@ -612,7 +611,6 @@ def _canonical_twisting_operator(self):
                     Quotient of Univariate Laurent Polynomial Ring in F1 over Integer Ring by the ideal (-1 + F1^2)
                 """
                 G, d = self._universal_cover_dict()
-                phi = G.abelianization_map()
                 abelG, R, I, images = G.abelianization_to_algebra(ZZ)
                 QRP = R.quotient_ring(I)
                 res = {}
@@ -908,7 +906,6 @@ def twisted_homology(self, n, reduced=False):
                 singred = singular_function("reduce")
                 singlift = singular_function("lift")
                 G, d = self._universal_cover_dict()
-                phi = G.abelianization_map()
                 abelG, R, I, images = G.abelianization_to_algebra(ZZ)
                 CC = self.twisted_chain_complex()
                 M1 = CC.differential(n).T

src/sage/categories/triangular_kac_moody_algebras.py

@@ -365,7 +365,6 @@ def _transpose_basis_mapping(self):
                      alphacheck[1]: alphacheck[1],
                      alphacheck[2]: alphacheck[2]}
                 """
-                Q = self.cartan_type().root_system().root_lattice()
                 K = self.basis().keys()
                 deg_map = {}
                 ret = {}

src/sage/geometry/lattice_polytope.py

@@ -591,7 +591,6 @@ def _sage_input_(self, sib, coerced):
         """
         if self._ambient is not self:
             raise NotImplementedError
-        data = self._vertices
         return sib.name('LatticePolytope')(sib(self._vertices), compute_vertices=False)
 
     def __contains__(self, point):

src/sage/homology/homology_vector_space_with_basis.py

@@ -690,10 +690,9 @@ def _acted_upon_(self, a, self_on_left):
             if m <= n:
                 return self.parent().zero()
 
-            if not self_on_left: # i.e., module element on left
+            if not self_on_left:  # i.e., module element on left
                 a = a.antipode()
             P = self.parent()
-            B = list(P.basis(m-n))
             return P._from_dict({x.support()[0]: self.eval(a * x)
                                  for x in sorted(self.parent().dual().basis(m-n))})
 

src/sage/knots/knotinfo.py

@@ -1353,7 +1353,6 @@ def cosmetic_crossing_conjecture_verified(self):
             return True
         if not cosmetic_crossing or cosmetic_crossing == 'Unknown':
             return False
-        verified = not knotinfo_bool(cosmetic_crossing)
         if not knotinfo_bool(cosmetic_crossing):
             return True
         raise AssertionError(f'{self} is a counterexample to the cosmetic crossing conjecture')

src/sage/libs/gap/test_long.py

@@ -15,7 +15,7 @@ def test_loop_1():
     """
     libgap.collect()
     for i in range(10000):
-        G = libgap.CyclicGroup(2)
+        _ = libgap.CyclicGroup(2)
 
 
 def test_loop_2():

src/sage/matroids/matroids_plot_helpers.py

@@ -859,7 +859,6 @@ def geomrep(M1, B1=None, lineorders1=None, pd=None, sp=False):
         pl = [list(x) for x in pts2.values()]
         lims = tracklims([None, None, None, None], [pt[0] for pt in pl],
                          [pt[1] for pt in pl])
-        j = 0
         for ll in trilines:
             if len(ll) >= 3:
                 ptsx, ptsy, x_i, y_i = createline(pts2, ll, lineorders1)

src/sage/modular/drinfeld_modform/ring.py

@@ -581,8 +581,6 @@ def coefficient_forms(self, a=None):
             ...
             TypeError: unable to convert a to an element in Fq[T]
         """
-        K = self._base_ring
-        T = K.gen()
         if a is None:
             return [self._generator_coefficient_form(i)
                     for i in range(1, self.rank() + 1)]

src/sage/modules/with_basis/representation.py

@@ -685,8 +685,8 @@
             5
         """
         if not is_closed and gens:
-            R = self.base_ring()
-            repr_mats = [self.representation_matrix(g) for g in self._semigroup.gens()]
+            repr_mats = [self.representation_matrix(g)
+                         for g in self._semigroup.gens()]
             amb_dim = self.dimension()
             SM = matrix([v._vector_() for v in gens])
             SM.echelonize()
@@ -2771,7 +2771,7 @@
         24 [2, 0, -1]
 
         sage: # long time
         sage: S211V = V.schur_functor([2, 1, 1])
         sage: S211V.dimension()
         105
         sage: SemistandardTableaux([2, 1, 1], max_entry=V.dimension()).cardinality()
@@ -2892,7 +2892,6 @@
             keys = list(V.basis().keys())
 
         ambient = tensor([V]*d)
-        I = ambient.indices()
         cla = SymmetricGroupAlgebra(R, SymmetricGroup(d)).young_symmetrizer(shape)
         mc = cla.monomial_coefficients(copy=False)
         gens = [ambient.sum_of_terms((tuple([k[i-1] for i in p.tuple()]), coeff)

src/sage/rings/function_field/drinfeld_modules/charzero_drinfeld_module.py

@@ -317,7 +317,6 @@ def logarithm(self, name='z'):
             True
         """
         L = LazyPowerSeriesRing(self._base, name)
-        zero = self._base.zero()
         q = self._Fq.cardinality()
 
         def coeff_log(k):

src/sage/rings/lazy_series_ring.py

@@ -2612,7 +2612,6 @@ def taylor(self, f):
             BR = R.base_ring()
             args = f.arguments()
             subs = {str(va): ZZ.zero() for va in args}
-            gens = R.gens()
             ell = len(subs)
             from sage.combinat.integer_vector import integer_vectors_nk_fast_iter
             from sage.arith.misc import factorial

src/sage/schemes/curves/projective_curve.py

@@ -1400,7 +1400,7 @@
             sage: set_verbose(-1)
             sage: P.<x,y,z> = ProjectiveSpace(QQ, 2)
             sage: C = Curve([(x^2 + y^2 - y*z - 2*z^2)*(y*z - x^2 + 2*z^2)*z + y^5], P)
             sage: C.ordinary_model() # long time (5 seconds)
             Scheme morphism:
               From: Projective Plane Curve over Number Field in a
                     with defining polynomial y^2 - 2 defined
@@ -2521,7 +2521,6 @@
             sage: C.function(C._map_from_function_field(f)) == f
             True
         """
-        F = self._function_field
         S = self.ambient_space().coordinate_ring()
         phi = self._open_affine._nonsingular_model[2]
         i = self._open_affine_index