gh-35409: fix pep8 E303 in folders starting with m

    
<!-- Please provide a concise, informative and self-explanatory title.
-->
<!-- Don't put issue numbers in the title. Put it in the Description
below. -->
<!-- For example, instead of "Fixes #12345", use "Add a new method to
multiply two integers" -->

### 📚 Description

fix all pep8 E303 warning in the folders whose name starts with the
letter m

purely done with autopep8:

```
$ autopep8 -i --select=E303 src/sage/m*/*.py
$ autopep8 -i --select=E303 src/sage/m*/*/*.py
```

<!-- Describe your changes here in detail. -->
<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes #12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. It should be `[x]` not `[x
]`. -->

- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- #12345: short description why this is a dependency
- #34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: #35409
Reported by: Frédéric Chapoton
Reviewer(s): David Coudert

src/sage/manifolds/chart.py

@@ -2317,7 +2317,6 @@ def _tighten_bounds(self):
         self._restrictions = new_restrictions
         self._fast_valid_coordinates = None
 
-
     def restrict(self, subset, restrictions=None):
         r"""
         Return the restriction of the chart to some open subset of its domain.

src/sage/manifolds/differentiable/automorphismfield_group.py

@@ -175,7 +175,6 @@ def __init__(self, vector_field_module):
         Parent.__init__(self, category=Groups())
         self._vmodule = vector_field_module
 
-
     #### Parent methods ####
 
     def _element_constructor_(self, comp=[], frame=None, name=None,
@@ -266,7 +265,6 @@ def _an_element_(self):
 
     #### End of parent methods ####
 
-
     #### Monoid methods ####
 
     @cached_method

src/sage/manifolds/differentiable/chart.py

@@ -679,7 +679,6 @@ def symbolic_velocities(self, left='D', right=None):
         return list(var(list_strings_velocities))
 
 
-
 #*****************************************************************************
 
 class RealDiffChart(DiffChart, RealChart):
@@ -1001,7 +1000,6 @@ def __init__(self, domain, coordinates, calc_method=None,
         self._frame = CoordFrame(self)
         self._coframe = self._frame._coframe
 
-
     def restrict(self, subset, restrictions=None):
         r"""
         Return the restriction of the chart to some subset.

src/sage/manifolds/differentiable/degenerate.py

@@ -368,7 +368,6 @@ def open_subset(self, name, latex_name=None, coord_def={}):
         return resu
 
 
-
 #*******************************************************************************************
 
 from sage.manifolds.differentiable.tensorfield_paral import TensorFieldParal

src/sage/manifolds/differentiable/degenerate_submanifold.py

@@ -1323,7 +1323,6 @@ def principal_directions(self, screen=None):
         self._principal_directions[screen._name] = res
         return res
 
-
     def mean_curvature(self, screen=None):
         r"""
 

src/sage/manifolds/differentiable/diff_form.py

@@ -1556,7 +1556,6 @@ def wedge(self, other):
         other_r = other.restrict(dom_resu)
         return FreeModuleAltForm.wedge(self_r, other_r)
 
-
     def interior_product(self, qvect):
         r"""
         Interior product with a multivector field.

src/sage/manifolds/differentiable/diff_map.py

@@ -1144,7 +1144,6 @@ def paral_comp(tcomp, chart1, chart2, coord2_1, jacob,
                             resu._components[frame] = comp
         return resu
 
-
     def pushforward(self, tensor):
         r"""
         Pushforward operator associated with ``self``.

src/sage/manifolds/differentiable/integrated_curve.py

@@ -579,7 +579,6 @@ def fast_CoF(pos, vel, M=M):
                                for f in transf]
                 self._fast_changes_of_chart[CoC] = fast_transf
 
-
         self._velocities = list(velocities) # converts to list
         # since might not already be a list (which is later required)
         self._curve_parameter = curve_parameter
@@ -1376,13 +1375,11 @@ def jacobian(t,y):
         # 'tangent_vector_eval_at', and in 'plot' when plotting the
         # tangent vectors.)
 
-
         if isinstance(sol, list):
             coords_sol = [point[0:dim + 1] for point in sol]
         else:
             coords_sol = sol[:, 0:dim + 1].tolist() # far faster in numpy
 
-
         if verbose:
             print("Numerical integration completed.\n\n" +
                   "Checking all points are in the chart domain...")
@@ -1779,7 +1776,6 @@ def solve_across_charts(self, charts=None, step=None, solution_key=None,
                             new_vel = self._fast_changes_of_frame[(new_chart.frame().restrict(inter),
                                chart.frame().restrict(inter))](last_pts, last_vel)
 
-
                             ics = new_pts + new_vel
                             chart = new_chart
 
@@ -2434,7 +2430,6 @@ def plot_integrated(self, chart=None, ambient_coords=None,
         thickness = kwds.pop('thickness')
         aspect_ratio = kwds.pop('aspect_ratio')
 
-
         #
         # The mapping, if present, and the chart with respect to which the curve
         # is plotted
@@ -3425,7 +3420,6 @@ def __init__(self, parent, affine_connection, curve_parameter,
 
         velocities = chart.symbolic_velocities()
 
-
         dim = parent.codomain().dim()
         i0 = parent.codomain().start_index()
 
@@ -3470,7 +3464,6 @@ def __init__(self, parent, affine_connection, curve_parameter,
                     equations_rhs_chart += [rhs.simplify_full()]
                 equations_rhs[chart] = equations_rhs_chart
 
-
         IntegratedCurve.__init__(self, parent, equations_rhs,
                                  velocities, curve_parameter,
                                  initial_tangent_vector, chart=chart,
@@ -3479,7 +3472,6 @@ def __init__(self, parent, affine_connection, curve_parameter,
 
         self._affine_connection = affine_connection
 
-
     def _repr_(self):
         r"""
         Return a string representation of ``self``.
@@ -3825,7 +3817,6 @@ class IntegratedGeodesic(IntegratedAutoparallelCurve):
     def __init__(self, parent, metric, curve_parameter,
                  initial_tangent_vector, chart=None, name=None,
                  latex_name=None, verbose=False, across_charts=False):
-
         r"""
         Construct a geodesic curve with respect to the given metric with the
         given initial tangent vector.

src/sage/manifolds/differentiable/levi_civita_connection.py

@@ -387,7 +387,6 @@ def _new_coef(self, frame):
                               start_index=self._domain._sindex,
                               output_formatter=DiffScalarField.coord_function)
 
-
     def coef(self, frame=None):
         r"""
         Return the connection coefficients relative to the given frame.

src/sage/manifolds/differentiable/manifold.py

@@ -2977,7 +2977,6 @@ def change_of_frame(self, frame1, frame2):
                              " has not been defined on the {}".format(self))
         return self._frame_changes[(frame1, frame2)]
 
-
     def set_change_of_frame(self, frame1, frame2, change_of_frame,
                          compute_inverse=True):
         r"""

src/sage/manifolds/differentiable/manifold_homset.py

@@ -777,7 +777,6 @@ def _repr_(self):
         description += "which actually are integrated curves"
         return description
 
-
     def _element_constructor_(self, equations_rhs, velocities,
                  curve_parameter, initial_tangent_vector, chart=None,
                  name=None, latex_name=None, verbose=False, across_charts=False):
@@ -1221,7 +1220,6 @@ def _repr_(self):
         description += "curves with respect to a certain affine connection"
         return description
 
-
     def _element_constructor_(self, affine_connection, curve_parameter,
                     initial_tangent_vector, chart=None, name=None,
                     latex_name=None, verbose=False, across_charts=False):

src/sage/manifolds/differentiable/metric.py

@@ -662,7 +662,6 @@ def set(self, symbiform):
                 rst = self.restrict(dom)
                 rst.set(symbiform_rst)
 
-
     def inverse(self, expansion_symbol=None, order=1):
         r"""
         Return the inverse metric.
@@ -879,7 +878,6 @@ def christoffel_symbols(self, chart=None):
             frame = chart._frame
         return self.connection().coef(frame)
 
-
     def christoffel_symbols_display(self, chart=None, symbol=None,
                 latex_symbol=None, index_labels=None, index_latex_labels=None,
                 coordinate_labels=True, only_nonzero=True,
@@ -1069,7 +1067,6 @@ def riemann(self, name=None, latex_name=None):
         """
         return self.connection().riemann(name, latex_name)
 
-
     def ricci(self, name=None, latex_name=None):
         r"""
         Return the Ricci tensor associated with the metric.
@@ -2271,7 +2268,6 @@ def restrict(self, subdomain, dest_map=None):
             self._restrictions[subdomain] = resu
         return self._restrictions[subdomain]
 
-
     def set(self, symbiform):
         r"""
         Define the metric from a field of symmetric bilinear forms.

src/sage/manifolds/differentiable/scalarfield.py

@@ -819,7 +819,6 @@ def differential(self) -> DiffForm:
     derivative = differential  # allows one to use functional notation,
                                # e.g. diff(f) for f.differential()
 
-
     def lie_derivative(self, vector):
         r"""
         Compute the Lie derivative with respect to a vector field.

src/sage/manifolds/differentiable/tensorfield_paral.py

@@ -657,7 +657,6 @@ def __init__(self, vector_field_module, tensor_type, name=None,
         # Initialization of derived quantities:
         self._init_derived()
 
-
     def _repr_(self):
         r"""
         String representation of ``self``.
@@ -769,7 +768,6 @@ def _preparse_display(self, basis=None, format_spec=None):
             basis = basis.frame()
         return (basis, format_spec)
 
-
     def _set_comp_unsafe(self, basis=None):
         r"""
         Return the components of the tensor field in a given vector frame
@@ -1511,7 +1509,6 @@ def paral_lie_deriv(a, b , coord_frame, chart_cp, local_list_ind):
                                     vc[[i]].coord_function(chart).diff(ind[k])
                     resc[[ind]] = rsum.scalar_field()
 
-
             #
             # 3/ Final result (the tensor)
             res = vf_module.tensor_from_comp(self._tensor_type, resc)

src/sage/manifolds/differentiable/vectorfield.py

@@ -359,7 +359,6 @@ def __call__(self, scalar):
             resu.set_name(name=name, latex_name=latex_name)
         return resu
 
-
     @options(max_range=8, scale=1, color='blue')
     def plot(self, chart=None, ambient_coords=None, mapping=None,
              chart_domain=None, fixed_coords=None, ranges=None,

src/sage/manifolds/differentiable/vectorfield_module.py

@@ -1206,7 +1206,6 @@ def metric(self, name: str, signature: Optional[int] = None, latex_name: Optiona
         return PseudoRiemannianMetric(self, name, signature=signature[0]-signature[1],
                                       latex_name=latex_name)
 
-
     def symplectic_form(
         self, name: Optional[str] = None, latex_name: Optional[str] = None
     ):

src/sage/manifolds/differentiable/vectorframe.py

@@ -764,7 +764,6 @@ def __init__(self, vector_field_module, symbol, latex_symbol=None,
         # NB: set(self._restrictions.values()) is identical to
         #     self._subframes
 
-
     ###### Methods that must be redefined by derived classes of ######
     ###### FreeModuleBasis                                      ######
 
@@ -1777,7 +1776,6 @@ def __init__(self, chart):
         # - force_free=True ensures that a free module is constructed in case
         #   it is the first call to the vector field module on chart.domain()
 
-
     ###### Methods that must be redefined by derived classes of ######
     ###### FreeModuleBasis                                      ######
 

src/sage/manifolds/scalarfield.py

@@ -2657,7 +2657,6 @@ def __neg__(self):
             result._latex_name = '-' + self._latex_name
         return result
 
-
     #########  CommutativeAlgebraElement arithmetic operators ########
 
     def _add_(self, other):

src/sage/manifolds/trivialization.py

@@ -693,7 +693,6 @@ def matrix(self):
         """
         return self._automorphism.matrix(self._frame1)
 
-
     def __eq__(self, other):
         r"""
         Equality operator.

src/sage/matrix/benchmark.py

@@ -562,7 +562,6 @@ def vecmat_ZZ(n=300, min=-9, max=9, system='sage', times=200):
         raise ValueError('unknown system "%s"'%system)
 
 
-
 #######################################################################
 # Dense Benchmarks over GF(p), for small p.
 #######################################################################
@@ -721,7 +720,6 @@ def matrix_add_GF(n=1000, p=16411, system='sage',times=100):
         raise ValueError('unknown system "%s"'%system)
 
 
-
 # Matrix multiplication over GF(p)
 
 def matrix_multiply_GF(n=100, p=16411, system='sage', times=3):

src/sage/matrix/compute_J_ideal.py

@@ -190,7 +190,6 @@ def lifting(p, t, A, G):
     """
     from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
 
-
     DX = A.parent().base()
     (X,) = DX.variable_names()
     D = DX.base_ring()
@@ -203,7 +202,6 @@ def lifting(p, t, A, G):
     if not (A*G % p**(t-1)).is_zero():
         raise ValueError("A*G not zero mod %s^%s" % (p, t-1))
 
-
     R = A*G/p**(t-1)
     R.change_ring(DX)
 
@@ -351,7 +349,6 @@ def __init__(self, B):
         self._DX = X.parent()
         self._cache = {}
 
-
     def find_monic_replacements(self, p, t, pt_generators, prev_nu):
         r"""
         Replace possibly non-monic generators of `N_{(p^t)}(B)` by monic
@@ -432,7 +429,6 @@ def find_monic_replacements(self, p, t, pt_generators, prev_nu):
 
         return replacements
 
-
     def current_nu(self, p, t, pt_generators, prev_nu):
         r"""
         Compute `(p^t)`-minimal polynomial of `B`.
@@ -482,7 +478,6 @@ def current_nu(self, p, t, pt_generators, prev_nu):
 
         from sage.misc.verbose import verbose
 
-
         if not all((g(self._B) % p**t).is_zero()
                    for g in pt_generators):
             raise ValueError("%s not in N_{(%s^%s)}(B)" %
@@ -519,7 +514,6 @@ def current_nu(self, p, t, pt_generators, prev_nu):
 
         return g
 
-
     def mccoy_column(self, p, t, nu):
         r"""
         Compute matrix for McCoy's criterion.
@@ -577,7 +571,6 @@ def mccoy_column(self, p, t, nu):
 
         return column
 
-
     def p_minimal_polynomials(self, p, s_max=None):
         r"""
         Compute `(p^s)`-minimal polynomials `\nu_s` of `B`.
@@ -768,7 +761,6 @@ def p_minimal_polynomials(self, p, s_max=None):
             d = self._A.ncols()
             G = matrix(self._DX, d, 0)
 
-
         while t < s_max:
             deg_prev_nu = nu.degree()
             t += 1
@@ -812,7 +804,6 @@ def p_minimal_polynomials(self, p, s_max=None):
 
         return p_min_polys
 
-
     def null_ideal(self, b=0):
         r"""
         Return the `(b)`-ideal `N_{(b)}(B)=\{f\in D[X] \mid f(B)\in M_n(bD)\}`.
@@ -877,7 +868,6 @@ def null_ideal(self, b=0):
 
         return self._DX.ideal(generators)
 
-
     def prime_candidates(self):
         r"""
         Determine those primes `p` where `\mu_B` might not be a
@@ -910,7 +900,6 @@ def prime_candidates(self):
 
         return [p for (p, t) in factor(T.det())]
 
-
     def integer_valued_polynomials_generators(self):
         r"""
         Determine the generators of the ring of integer valued polynomials on `B`.

src/sage/media/wav.py

@@ -102,7 +102,6 @@ def __init__(self, data=None, **kwds):
         else:
             raise ValueError("Must give a filename")
 
-
     def save(self, filename='sage.wav'):
         r"""
         Save this wave file to disk, either as a Sage sobj or as a .wav file.