sagemathgh-38610: fix and activate E303 check in pyx files

    
This is activating the fix for

E303 too many blank lines

in all pyx files.


### 📝 Checklist

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- [ ] The title is concise and informative.
- [ ] 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 and checked the documentation
preview.

### ⌛ Dependencies

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URL: sagemath#38610
Reported by: Frédéric Chapoton
Reviewer(s): Kwankyu Lee

src/sage/libs/coxeter3/decl.pxd

@@ -33,7 +33,6 @@ cdef extern from "coxeter/coxtypes.h" namespace "coxtypes":
     ctypedef unsigned short Length
     ctypedef Ulong StarOp             # for numbering star operations
 
-
     #################
     #    CoxWord    #
     #################

src/sage/libs/ecl.pxd

@@ -147,7 +147,6 @@ cdef extern from "ecl/ecl.h":
     ecl_character ecl_char(cl_object s, cl_index i)
     ecl_character ecl_char_set(cl_object s, cl_index i, ecl_character c)
 
-
     # S-expr evaluation and function calls
 
     cl_object cl_safe_eval(cl_object form, cl_object env, cl_object value)

src/sage/libs/linbox/fflas.pxd

@@ -28,7 +28,6 @@ cdef extern from "fflas-ffpack/fflas-ffpack.h" namespace "FFLAS":
         FflasNoTrans
         FflasTrans
 
-
     ctypedef enum FFLAS_SIDE:
         FflasRight
 

src/sage/libs/m4rie.pxd

@@ -173,7 +173,6 @@ cdef extern from "m4rie/m4rie.h":
 
     void mzd_slice_row_add(mzd_slice_t *A, size_t sourcerow, size_t destrow)
 
-
     void mzd_slice_row_clear_offset(mzd_slice_t *A, size_t row, size_t coloffset)
 
     void mzd_slice_print(mzd_slice_t *A)

src/sage/libs/meataxe.pxd

@@ -113,7 +113,6 @@ cdef extern from "meataxe.h":
     Matrix_t *MatLoad(char *fn) except? NULL
     int MatSave(Matrix_t *mat, char *fn) except -1
 
-
     ## Basic Arithmetic  ## general rule: dest is changed, src/mat are unchanged!
     Matrix_t *MatTransposed(Matrix_t *src) except NULL
     Matrix_t *MatAdd(Matrix_t *dest, Matrix_t *src) except NULL

src/sage/libs/ntl/GF2X.pxd

@@ -58,7 +58,6 @@ cdef extern from "ntlwrap.h":
     void GF2XModulus_build "build"(GF2XModulus_c F, GF2X_c f) # MUST be called before using the modulus
     long GF2XModulus_deg "deg"(GF2XModulus_c F)
 
-
     GF2X_c GF2XModulus_GF2X "GF2X" (GF2XModulus_c m)
 
     GF2X_c GF2X_IrredPolyMod "IrredPolyMod" (GF2X_c g, GF2XModulus_c F)
@@ -72,7 +71,6 @@ cdef extern from "ntlwrap.h":
     void GF2X_PowerXPlusAMod_pre "PowerXPlusAMod"(GF2X_c x, GF2_c a, GF2_c e, GF2XModulus_c F)
     void GF2X_PowerXPlusAMod_long_pre "PowerXPlusAMod"(GF2X_c x, GF2_c a, long e, GF2XModulus_c F)
 
-
     # x = g(h) mod f; deg(h) < n
     void GF2X_CompMod "CompMod"(GF2X_c x, GF2X_c g, GF2X_c h, GF2XModulus_c F)
     # xi = gi(h) mod f (i=1,2), deg(h) < n.

src/sage/libs/singular/decl.pxd

@@ -151,7 +151,6 @@ cdef extern from "singular/Singular/libsingular.h":
         void    (*cfWrite)(number* a, const n_Procs_s* r)
         void    (*cfNormalize)(number* a,  const n_Procs_s* r)
 
-
         bint (*cfDivBy)(number* a, number* b, const n_Procs_s* r)
         bint (*cfEqual)(number* a,number* b, const n_Procs_s* )
         bint (*cfIsZero)(number* a, const n_Procs_s* ) # algebraic number comparison with zero
@@ -160,7 +159,6 @@ cdef extern from "singular/Singular/libsingular.h":
         bint (*cfGreaterZero)(number* a, const n_Procs_s* )
         void (*cfPower)(number* a, int i, number* * result,  const n_Procs_s* r) # algebraic number power
 
-
         ring *extRing
         int ch
         mpz_ptr modBase
@@ -211,7 +209,6 @@ cdef extern from "singular/Singular/libsingular.h":
         int pCompIndex # index of components
         unsigned long bitmask # mask for getting single exponents
 
-
         n_Procs_s*    cf # coefficient field/ring
         int ref
 
@@ -793,7 +790,6 @@ cdef extern from "singular/Singular/libsingular.h":
 
     number *nlCopy(number *)
 
-
     # number to integer handle
 
     long SR_TO_INT(number *)
@@ -813,7 +809,6 @@ cdef extern from "singular/Singular/libsingular.h":
 
     void id_Delete(ideal **, ring *)
 
-
     # lifting
 
     ideal *idLift(ideal *mod, ideal *submod, ideal **rest, int goodShape, int isSB, int divide)

src/sage/libs/symmetrica/sb.pxi

@@ -51,7 +51,6 @@ def mult_schubert_schubert_symmetrica(a, b):
         freeall(cres)
         raise err
 
-
     sig_on()
     mult_schubert_schubert(ca, cb, cres)
     sig_off()

src/sage/libs/symmetrica/schur.pxi

@@ -28,7 +28,6 @@ cdef extern from 'symmetrica/def.h':
     INT t_HOMSYM_MONOMIAL(OP a, OP b)
     INT t_HOMSYM_ELMSYM(OP a, OP b)
 
-
     INT t_POWSYM_SCHUR(OP a, OP b)
     INT t_SCHUR_POWSYM(OP a, OP b)
     INT t_POWSYM_HOMSYM(OP a, OP b)

src/sage/matrix/matrix_modn_dense_template.pxi

@@ -854,7 +854,6 @@ cdef class Matrix_modn_dense_template(Matrix_dense):
             A.subdivide(*self.subdivisions())
         return A
 
-
     cpdef _add_(self, right):
         r"""
         Add two dense matrices over `\Z/n\Z`.
@@ -898,7 +897,6 @@ cdef class Matrix_modn_dense_template(Matrix_dense):
         sig_off()
         return M
 
-
     cpdef _sub_(self, right):
         r"""
         Subtract two dense matrices over `\Z/n\Z`.
@@ -1404,7 +1402,6 @@ cdef class Matrix_modn_dense_template(Matrix_dense):
         self.cache(cache_key, g)
         return g
 
-
     def minpoly(self, var='x', algorithm='linbox', proof=None):
         """
         Return the minimal polynomial of ``self``.

src/sage/rings/finite_rings/hom_finite_field.pyx

@@ -150,7 +150,6 @@ cdef class SectionFiniteFieldHomomorphism_generic(Section):
                 return root
         raise ValueError("%s is not in the image of %s" % (x, self._inverse))
 
-
     def _repr_(self):
         """
         Return a string representation of this section.
@@ -167,7 +166,6 @@ cdef class SectionFiniteFieldHomomorphism_generic(Section):
         """
         return "Section of %s" % self._inverse
 
-
     def _latex_(self):
         r"""
         Return a latex representation of this section.
@@ -321,7 +319,6 @@ cdef class FiniteFieldHomomorphism_generic(RingHomomorphism_im_gens):
             f = f.map_coefficients(bm)
         return f(self.im_gens()[0])
 
-
     def is_injective(self):
         """
         Return ``True`` since a embedding between finite fields is
@@ -338,7 +335,6 @@ cdef class FiniteFieldHomomorphism_generic(RingHomomorphism_im_gens):
         """
         return True
 
-
     def is_surjective(self):
         """
         Return ``True`` if this embedding is surjective (and hence an
@@ -358,7 +354,6 @@ cdef class FiniteFieldHomomorphism_generic(RingHomomorphism_im_gens):
         """
         return self.domain().cardinality() == self.codomain().cardinality()
 
-
     @cached_method
     def section(self):
         """
@@ -544,7 +539,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
         self._q = domain.characteristic() ** self._power
         RingHomomorphism.__init__(self, Hom(domain, domain))
 
-
     def _repr_(self):
         """
         Return a string representation of this endomorphism.
@@ -568,7 +562,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
         s += " %s" % self.domain()
         return s
 
-
     def _repr_short(self):
         """
         Return a short string representation of this endomorphism.
@@ -591,7 +584,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
             s = "%s |--> %s^(%s^%s)" % (name, name, self.domain().characteristic(), self._power)
         return s
 
-
     def _latex_(self):
         r"""
         Return a latex representation of this endomorphism.
@@ -615,7 +607,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
             s = "%s \\mapsto %s^{%s^{%s}}" % (name, name, self.domain().characteristic(), self._power)
         return s
 
-
     cpdef Element _call_(self, x):
         """
         TESTS::
@@ -632,7 +623,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
         else:
             return x.pth_power(self._power)
 
-
     def order(self):
         """
         Return the order of this endomorphism.
@@ -673,7 +663,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
         """
         return self._power
 
-
     def __pow__(self, n, modulus):
         """
         Return the `n`-th iterate of this endomorphism.
@@ -735,7 +724,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
         else:
             return RingHomomorphism._composition(self, right)
 
-
     def fixed_field(self):
         """
         Return the fixed field of ``self``.
@@ -780,7 +768,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
             f = FiniteFieldHomomorphism_generic(Hom(k, self.domain()))
         return k, f
 
-
     def is_injective(self):
         """
         Return ``True`` since any power of the Frobenius endomorphism
@@ -795,7 +782,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
         """
         return True
 
-
     def is_surjective(self):
         """
         Return ``True`` since any power of the Frobenius endomorphism
@@ -810,7 +796,6 @@ cdef class FrobeniusEndomorphism_finite_field(FrobeniusEndomorphism_generic):
         """
         return True
 
-
     def is_identity(self):
         """
         Return ``True`` if this morphism is the identity morphism.

src/sage/rings/polynomial/polynomial_integer_dense_flint.pyx

@@ -102,7 +102,6 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
         """
         fmpz_poly_init(self._poly)
 
-
     def __dealloc__(self):
         r"""
         Call the underlying FLINT fmpz_poly destructor
@@ -652,7 +651,6 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
         sig_off()
         return x
 
-
     cpdef _sub_(self, right):
         r"""
         Return ``self`` minus ``right``.
@@ -672,7 +670,6 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
         sig_off()
         return x
 
-
     cpdef _neg_(self):
         r"""
         Return negative of ``self``.
@@ -834,7 +831,6 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
         sig_off()
         return x
 
-
     @coerce_binop
     def lcm(self, right):
         """
@@ -955,7 +951,6 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
         else:
             return self._parent(rr), ss, tt
 
-
     cpdef _mul_(self, right):
         r"""
         Return ``self`` multiplied by ``right``.
@@ -1360,11 +1355,10 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
 
         return real_roots(self)
 
-##     def __copy__(self):
-##         f = Polynomial_integer_dense(self.parent())
-##         f._poly = self._poly.copy()
-##         return f
-
+    #     def __copy__(self):
+    #         f = Polynomial_integer_dense(self.parent())
+    #         f._poly = self._poly.copy()
+    #         return f
 
     def degree(self, gen=None):
         """
@@ -1485,7 +1479,6 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
             variable = self.parent().variable_name()
         return pari(self.list()).Polrev(variable)
 
-
     def squarefree_decomposition(Polynomial_integer_dense_flint self):
         """
         Return the square-free decomposition of ``self``.  This is
@@ -1743,7 +1736,6 @@ cdef class Polynomial_integer_dense_flint(Polynomial):
         """
         return [self.get_unsafe(i) for i in range(self.degree()+1)]
 
-
     @coerce_binop
     def resultant(self, other, proof=True):
         """