Trac #33945: fix pycodestyle E306 outside of algebras,rings,graphs,sc…

…hemes,categories

this is about

missing whitelines before nested def

URL: https://trac.sagemath.org/33945
Reported by: chapoton
Ticket author(s): Frédéric Chapoton
Reviewer(s): Travis Scrimshaw

src/sage/calculus/desolvers.py

@@ -574,6 +574,7 @@ def desolve(de, dvar, ics=None, ivar=None, show_method=False, contrib_ode=False,
     dvar_str=P(dvar.operator()).str()
     ivar_str=P(ivar).str()
     de00 = de00.str()
+
     def sanitize_var(exprs):
         return exprs.replace("'"+dvar_str+"("+ivar_str+")",dvar_str)
     de0 = sanitize_var(de00)
@@ -811,6 +812,7 @@ def desolve_laplace(de, dvar, ics=None, ivar=None):
     ## verbatim copy from desolve - end
 
     dvar_str = str(dvar)
+
     def sanitize_var(exprs):  # 'y(x) -> y(x)
         return exprs.replace("'"+dvar_str,dvar_str)
     de0=de._maxima_()
@@ -1680,25 +1682,25 @@ def Dfun(y, t):
             variabs = dvars[:]
             variabs.append(ivar)
             for de in des:
-                desc.append(fast_float(de,*variabs))
+                desc.append(fast_float(de, *variabs))
 
-            def func(y,t):
+            def func(y, t):
                 v = list(y[:])
                 v.append(t)
                 return [dec(*v) for dec in desc]
 
             if not compute_jac:
-                Dfun=None
+                Dfun = None
             else:
-                J = jacobian(des,dvars)
+                J = jacobian(des, dvars)
                 J = [list(v) for v in J]
-                J = fast_float(J,*variabs)
-                def Dfun(y,t):
+                J = fast_float(J, *variabs)
+
+                def Dfun(y, t):
                     v = list(y[:])
                     v.append(t)
                     return [[element(*v) for element in row] for row in J]
 
-
         sol=odeint(func, ics, times, args=args, Dfun=Dfun, rtol=rtol, atol=atol,
             tcrit=tcrit, h0=h0, hmax=hmax, hmin=hmin, ixpr=ixpr, mxstep=mxstep,
             mxhnil=mxhnil, mxordn=mxordn, mxords=mxords, printmessg=printmessg)

src/sage/categories/finite_posets.py

@@ -1901,14 +1901,16 @@ def order_ideals_lattice(self, as_ideals=True, facade=None):
             else:
                 from sage.misc.cachefunc import cached_function
                 antichains = [tuple(a) for a in self.antichains()]
+
                 @cached_function
                 def is_above(a, xb):
                     return any(self.is_lequal(xa, xb) for xa in a)
+
                 def compare(a, b):
                     return all(is_above(a, xb) for xb in b)
                 return LatticePoset((antichains, compare), facade=facade)
 
-        @abstract_method(optional = True)
+        @abstract_method(optional=True)
         def antichains(self):
             r"""
             Return all antichains of ``self``.

src/sage/coding/guruswami_sudan/gs_decoder.py

@@ -356,6 +356,7 @@ def guruswami_sudan_decoding_radius(C = None, n_k = None, l = None, s = None):
             (92, (2, 6))
         """
         n,k = n_k_params(C, n_k)
+
         def get_tau(s,l):
             "Return the decoding radius given this s and l"
             if s<=0 or l<=0:

src/sage/coding/guruswami_sudan/interpolation.py

@@ -337,11 +337,13 @@ def lee_osullivan_module(points, parameters, wy):
     y = PFy.gens()[0]
     ybasis = [(y-R)**i * G**(s-i) for i in range(0, s+1)] \
             + [y**(i-s) * (y-R)**s for i in range(s+1, l+1)]
+
     def pad(lst):
         return lst + [0]*(l+1-len(lst))
     modbasis = [pad(yb.coefficients(sparse=False)) for yb in ybasis]
     return matrix(PF, modbasis)
 
+
 def gs_interpolation_lee_osullivan(points, tau, parameters, wy):
     r"""
     Returns an interpolation polynomial Q(x,y) for the given input using the

src/sage/coding/information_set_decoder.py

@@ -555,6 +555,7 @@ def calibrate(self):
         F = C.base_ring()
         q = F.cardinality()
         Fstar = F.list()[1:]
+
         def time_information_set_steps():
             before = process_time()
             while True:
@@ -565,6 +566,7 @@ def time_information_set_steps():
                 except ZeroDivisionError:
                     continue
                 return process_time() - before
+
         def time_search_loop(p):
             y = random_vector(F, n)
             g = random_matrix(F, p, n).rows()

src/sage/combinat/cluster_algebra_quiver/quiver.py

@@ -561,6 +561,7 @@ def plot(self, circular=True, center=(0, 0), directed=True, mark=None,
         from sage.all import e, pi, I
         graphs = GraphGenerators()
         # returns positions for graph vertices on two concentric cycles with radius 1 and 2
+
         def _graphs_concentric_circles(n, m):
             g1 = graphs.CycleGraph(n).get_pos()
             g2 = graphs.CycleGraph(m).get_pos()

src/sage/crypto/sboxes.py

@@ -237,6 +237,7 @@ def bf(x):
 
     elif isinstance(bf, (BooleanFunction,)):
         bf_f2 = bf
+
         def bf(x):
             xprime = map(int, x.polynomial().list())
             xprime += [0]*(n-1 - len(xprime))

src/sage/databases/findstat.py

@@ -645,6 +645,7 @@ def _data_from_iterable(iterable, mapping=False, domain=None,
         codomain = FindStatCollection(vals)
 
     all_elements = set()
+
     def sanitize_pair(elts, vals):
         if domain.is_element(elts):
             elts = [elts]
@@ -1050,6 +1051,7 @@ def findstat(query=None, values=None, distribution=None, domain=None,
         raise ValueError("the maximal number of values for a FindStat query must be a non-negative integer less than or equal to %i" % FINDSTAT_MAX_VALUES)
 
     check_collection = True
+
     def get_values(raw, domain=None):
         if callable(raw):
             known_terms = _data_from_function(raw, domain)
@@ -1272,6 +1274,7 @@ def findmap(*args, **kwargs):
         raise ValueError("the maximal number of values for a FindStat query must be a non-negative integer less than or equal to %i" % FINDSTAT_MAX_VALUES)
 
     check_collection = True
+
     def get_values(raw, domain=None, codomain=None):
         if callable(raw):
             known_terms = _data_from_function(raw, domain)

src/sage/databases/sql_db.py

@@ -349,6 +349,7 @@ def _create_print_table(cur, col_titles, **kwds):
                 continue
     global p
     p = 0
+
     def row_str(row, html):
         f = 0
         global p

src/sage/doctest/control.py

@@ -956,6 +956,7 @@ def filter_sources(self):
         # Filter the sources to only include those with failing doctests if the --failed option is passed
         if self.options.failed:
             self.log("Only doctesting files that failed last test.")
+
             def is_failure(source):
                 basename = source.basename
                 return basename not in self.stats or self.stats[basename].get('failed')
@@ -995,6 +996,7 @@ def sort_sources(self):
         if self.options.nthreads > 1 and len(self.sources) > self.options.nthreads:
             self.log("Sorting sources by runtime so that slower doctests are run first....")
             default = dict(walltime=0)
+
             def sort_key(source):
                 basename = source.basename
                 return -self.stats.get(basename, default).get('walltime'), basename

src/sage/doctest/fixtures.py

@@ -372,6 +372,7 @@ def trace_method(obj, meth, **kwds):
     from sage.cpython.getattr import raw_getattr
     f = raw_getattr(obj, meth)
     t = AttributeAccessTracerProxy(obj, **kwds)
+
     @wraps(f)
     def g(*args, **kwds):
         arglst = [reproducible_repr(arg) for arg in args]

src/sage/functions/orthogonal_polys.py

@@ -2810,6 +2810,7 @@ def eval_formula(self, n, x, b, c):
              + (3*b^2 + 6*b - 3*b^2/c - 3*b/c - 3*b/c^2 - 2/c^3 + 2)*x + 2*b
         """
         from sage.misc.misc_c import prod
+
         def P(val, k):
             return prod(val + j for j in range(k))
         return sum((-1)**k * binomial(n, k) * binomial(x, k) * factorial(k)

src/sage/geometry/triangulation/point_configuration.py

@@ -1978,6 +1978,7 @@ def placing_triangulation(self, point_order=None):
             (<0,2,4>, <0,3,4>, <1,2,4>, <1,3,4>)
         """
         facet_normals = dict()
+
         def facets_of_simplex(simplex):
             """
             Return the facets of the simplex and store the normals in facet_normals

src/sage/groups/braid.py

@@ -2095,6 +2095,7 @@ def reduced_word(self):
             in parallel.
         """
         M = self._algebra._indices
+
         def tuple_to_word(q_tuple):
             return M.prod(self._gens[i] ** exp
                           for i, exp in enumerate(q_tuple))

src/sage/groups/cubic_braid.py

@@ -1214,6 +1214,7 @@ def create_sympl_realization(self, m):
             # matrix.
             # -----------------------------------------------------------
             from sage.matrix.constructor import matrix
+
             def transvec2mat(v, bas=bas, bform=bform, fact=1):
                 t = [x + fact*(x * bform * v) * v for x in bas]
                 return matrix(bform.base_ring(),  t)
@@ -1295,6 +1296,7 @@ def create_unitary_realization(self, m):
             # matrix.
             # -----------------------------------------------------------
             from sage.matrix.constructor import matrix
+
             def transvec2mat(v, bas=bas, bform=bform, fact=a):
                 # note x does not change under conjugation, since it belongs to standard basis
                 t = [x + fact *(x * bform * v.conjugate()) * v for x in bas]

src/sage/homology/chain_complex.py

@@ -1337,6 +1337,7 @@ def _homology_in_degree(self, deg, base_ring, verbose, generators, algorithm):
             print('Computing homology of the chain complex in dimension %s...' % deg)
 
         fraction_field = base_ring.fraction_field()
+
         def change_ring(X):
             if X.base_ring() is base_ring:
                 return X

src/sage/homology/hochschild_complex.py

@@ -269,6 +269,7 @@ def boundary(self, d):
         Fd = self.module(d-1)
         Fd1 = self.module(d)
         mone = -one
+
         def on_basis(k):
             p = self._M.monomial(k[0]) * self._A.monomial(k[1])
             ret = Fd._from_dict({(m,) + k[2:]: c for m,c in p}, remove_zeros=False)

src/sage/interfaces/frobby.py

@@ -211,6 +211,7 @@ def associated_primes(self, monomial_ideal):
         if lines[-1]=='':
             lines.pop(-1)
         lists = [[int(_) for _ in a.split()] for a in lines]
+
         def to_monomial(exps):
             return [v ** e for v, e in zip(monomial_ideal.ring().gens(), exps) if e != 0]
         return [monomial_ideal.ring().ideal(to_monomial(a)) for a in lists]
@@ -338,8 +339,9 @@ def _parse_ideals(self, string, ring):
                 for i in range(nrows):
                     nmatrix+=lines.pop(0)+'\n'
                 matrices.append(nmatrix)
+
         def to_ideal(exps):
-            if len(exps)==0:
+            if len(exps) == 0:
                 return ring.zero_ideal()
             gens = [prod([v ** e for v, e in zip(ring.gens(), expo) if e != 0]) for expo in exps]
             return ring.ideal(gens or ring(1))

src/sage/knots/link.py

@@ -3918,6 +3918,7 @@ def get_knotinfo(self, mirror_version=True, unique=True):
         # over :class:`KnotInfo` should be returned
 
         non_unique_hint = '\nuse keyword argument `unique` to obtain more details'
+
         def answer(L):
             r"""
             Return a single item of the KnotInfo database according to the keyword

src/sage/libs/singular/standard_options.py

@@ -132,6 +132,7 @@ def libsingular_gb_standard_options(func):
        does not need to use it manually.
     """
     from sage.misc.decorators import sage_wraps
+
     @sage_wraps(func)
     def wrapper(*args, **kwds):
         """

src/sage/manifolds/differentiable/vectorfield.py

@@ -834,7 +834,6 @@ def plot(self, chart=None, ambient_coords=None, mapping=None,
                                extra_options)
                               for ind_part in local_list]
 
-
             # definition of the parallel function
             @parallel(p_iter='multiprocessing', ncpus=nproc)
             def add_point_plot(vector, dom, xx_list, chart_domain, chart,

src/sage/manifolds/subset.py

@@ -971,6 +971,7 @@ def vertex_family(subset):
             def vertex_family(subset):
                 return ManifoldSubsetFiniteFamily([subset])
         subset_to_vertex = {}
+
         def vertex(subset):
             try:
                 return subset_to_vertex[subset]
@@ -2307,6 +2308,7 @@ def _reduce_intersection_members(subsets):
         subsets = set(subsets)
         if not subsets:
             raise TypeError('input set must be nonempty')
+
         def reduce():
             # Greedily replace inclusion chains by their minimal element
             # and pairs with declared intersections by their intersection
@@ -2531,6 +2533,7 @@ def _reduce_union_members(subsets):
 
         """
         subsets = set(subsets)
+
         def reduce():
             # Greedily replace inclusion chains by their maximal element
             # and pairs with declared unions by their union

src/sage/misc/explain_pickle.py

@@ -2432,6 +2432,7 @@ def unpickle_newobj(klass, args):
     pickle = b"P0\nP1\n\x81."
 
     pers = [klass, args]
+
     def pers_load(id):
         return pers[int(id)]
 

src/sage/misc/superseded.py

@@ -304,6 +304,7 @@ def __call__(self, func):
             (3,) {'what': 'Hello'}
         """
         from sage.misc.decorators import sage_wraps
+
         @sage_wraps(func)
         def wrapper(*args, **kwds):
             if not wrapper._already_issued:

src/sage/modular/modform/numerical.py

@@ -334,6 +334,7 @@ def _eigendata(self):
         x = self._easy_vector()
 
         B = self._eigenvectors()
+
         def phi(y):
             """
             Take coefficients and a basis, and return that
@@ -416,6 +417,7 @@ def eigenvalues(self, primes):
                 raise ValueError('each element of primes must be prime.')
         phi_x, phi_x_inv, nzp, x_nzp = self._eigendata()
         B = self._eigenvectors()
+
         def phi(y):
             """
             Take coefficients and a basis, and return that

src/sage/modular/modsym/ambient.py

@@ -2473,6 +2473,7 @@ def _pari_pairing(self):
         m = Integer(self.weight() - 2)
         R = PolynomialRing(QQ, 'x')
         x = R.gen()
+
         def ev(s):
             # The Manin symbol s = X^i (c, d) corresponds to the
             # modular symbol (dX - bY)^i (-cX + aY)^(m - i) {b/d, a/c}.
@@ -2481,7 +2482,7 @@ def ev(s):
             i = s.i
             a, b, c, d = s.lift_to_sl2z()
             e = [R(p) for p in P.mseval(I, matrix(2, 2, [b, a, d, c]))]
-            g = (d*x - b)**i * (-c*x + a)**(m - i)
+            g = (d * x - b)**i * (-c * x + a)**(m - i)
             return [sum(f[j] * g[m - j] / m.binomial(j) for j in range(m + 1))
                     for f in e]
         return matrix([ev(s) for s in self.manin_symbols_basis()])

src/sage/modules/filtered_vector_space.py

@@ -1003,6 +1003,7 @@ def direct_sum(self, other):
         generators = \
             [ list(v) + [base_ring.zero()]*other.dimension() for v in self_gens  ] + \
             [ [base_ring.zero()]*self.dimension() + list(v)  for v in other_gens ]
+
         # construct the filtration dictionary
         def join_indices(self_indices, other_indices):
             self_indices = tuple(self_indices)

src/sage/modules/with_basis/morphism.py

@@ -849,6 +849,7 @@ def section(self):
             retract_dom = None
         else:
             on_basis = self.on_basis()
+
             def retract_dom(i):
                 self._dominant_item(on_basis(i))[0]
 

src/sage/monoids/indexed_free_monoid.py

@@ -143,6 +143,7 @@ def _ascii_art_(self):
             ascii_art_gen = lambda m: P._ascii_art_generator(m[0])
         else:
             pref = AsciiArt([P.prefix()])
+
             def ascii_art_gen(m):
                 if m[1] != 1:
                     r = (AsciiArt([" " * len(pref)]) + ascii_art(m[1]))

src/sage/parallel/decorate.py

@@ -473,10 +473,12 @@ def __call__(self, f):
         P = Parallel(p_iter='fork', ncpus=1, timeout=self.timeout,
                      verbose=self.verbose)
         g = P(f)
+
         def h(*args, **kwds):
             return list(g([(args, kwds)]))[0][1]
         return h
 
+
 def fork(f=None, timeout=0, verbose=False):
     """
     Decorate a function so that when called it runs in a forked

src/sage/plot/hyperbolic_polygon.py

@@ -308,6 +308,7 @@ def hyperbolic_polygon(pts, model="UHP", resolution=200, **options):
             xlist = [p[0] for p in pts]
             ylist = [p[1] for p in pts]
             zlist = [p[2] for p in pts]
+
             def region(x, y, z):
                 return _winding_number(arc_points, (x, y, z)) != 0
             g = g + implicit_plot3d(x**2 + y**2 - z**2 == -1,