gh-40218: some cleanup in combinat/sf
    
just a little spring cleanup

### 📝 Checklist

- [x] The title is concise and informative.
- [ ] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
    
URL: #40218
Reported by: Frédéric Chapoton
Reviewer(s): Frédéric Chapoton, Kwankyu Lee, Martin Rubey

Author: Release Manager

src/sage/combinat/sf/abreu_nigro.py

@@ -17,9 +17,10 @@
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from . import multiplicative
 from sage.misc.cachefunc import cached_method
 
+from . import multiplicative
+
 
 class SymmetricFunctionAlgebra_AbreuNigro(multiplicative.SymmetricFunctionAlgebra_multiplicative):
     r"""

src/sage/combinat/sf/all.py

@@ -31,6 +31,7 @@
 """
 # install the docstring of this module to the containing package
 from sage.misc.namespace_package import install_doc
+
 install_doc(__package__, __doc__)
 
 from sage.misc.lazy_import import lazy_import

src/sage/combinat/sf/classical.py

@@ -17,18 +17,12 @@
 #
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
+from sage.combinat.partition import _Partitions
 from sage.rings.integer import Integer
 from sage.rings.integer_ring import ZZ
 from sage.rings.rational_field import QQ
-from sage.combinat.partition import _Partitions
-
 
-from . import hall_littlewood
-from . import sfa
-from . import llt
-from . import macdonald
-from . import jack
-from . import orthotriang
+from . import hall_littlewood, jack, llt, macdonald, orthotriang, sfa
 
 translate = {'monomial': 'MONOMIAL',
              'homogeneous': 'HOMSYM',

src/sage/combinat/sf/dual.py

@@ -17,11 +17,12 @@
 #
 #                  https://www.gnu.org/licenses/
 #*****************************************************************************
-from sage.categories.morphism import SetMorphism
-from sage.categories.homset import Hom
-from sage.matrix.constructor import matrix
 import sage.combinat.partition
 import sage.data_structures.blas_dict as blas
+from sage.categories.homset import Hom
+from sage.categories.morphism import SetMorphism
+from sage.matrix.constructor import matrix
+
 from . import classical
 
 
@@ -988,6 +989,7 @@ def _repr_(self):
 
 # Backward compatibility for unpickling
 from sage.misc.persist import register_unpickle_override
+
 register_unpickle_override('sage.combinat.sf.dual',
                            'SymmetricFunctionAlgebraElement_dual',
                            SymmetricFunctionAlgebra_dual.Element)

src/sage/combinat/sf/elementary.py

@@ -20,11 +20,10 @@
 #*****************************************************************************
 from sage.arith.misc import binomial, factorial
 from sage.combinat.partition import Partition
-from sage.combinat.sf import multiplicative, classical
+from sage.combinat.sf import classical, multiplicative
 from sage.misc.misc_c import prod
 from sage.rings.infinity import infinity
 
-
 ###################################
 #                                 #
 # Elementary Symmetric Functions  #
@@ -401,7 +400,9 @@ def get_variable(ring, name):
                 try:
                     ring(name)
                 except TypeError:
-                    from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
+                    from sage.rings.polynomial.polynomial_ring_constructor import (
+                        PolynomialRing,
+                    )
                     return PolynomialRing(ring, name).gen()
                 else:
                     raise ValueError("the variable %s is in the base ring, pass it explicitly" % name)
@@ -498,7 +499,9 @@ def get_variable(ring, name):
                 try:
                     ring(name)
                 except TypeError:
-                    from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
+                    from sage.rings.polynomial.polynomial_ring_constructor import (
+                        PolynomialRing,
+                    )
                     return PolynomialRing(ring, name).gen()
                 else:
                     raise ValueError("the variable %s is in the base ring, pass it explicitly" % name)
@@ -539,6 +542,7 @@ def f(partition):
 
 # Backward compatibility for unpickling
 from sage.misc.persist import register_unpickle_override
+
 register_unpickle_override('sage.combinat.sf.elementary',
                            'SymmetricFunctionAlgebraElement_elementary',
                            SymmetricFunctionAlgebra_elementary.Element)

src/sage/combinat/sf/hall_littlewood.py

@@ -19,14 +19,15 @@
 #                  http://www.gnu.org/licenses/
 #*****************************************************************************
 
-from sage.structure.unique_representation import UniqueRepresentation
-from sage.libs.symmetrica.all import hall_littlewood
-from . import sfa
 import sage.combinat.partition
-from sage.matrix.constructor import matrix
-from sage.categories.morphism import SetMorphism
 from sage.categories.homset import Hom
+from sage.categories.morphism import SetMorphism
+from sage.libs.symmetrica.all import hall_littlewood
+from sage.matrix.constructor import matrix
 from sage.rings.rational_field import QQ
+from sage.structure.unique_representation import UniqueRepresentation
+
+from . import sfa
 
 # P basis cache
 p_to_s_cache = {}

src/sage/combinat/sf/hecke.py

@@ -24,7 +24,7 @@
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from sage.combinat.partition import _Partitions, Partitions
+from sage.combinat.partition import Partitions, _Partitions
 from sage.combinat.sf.multiplicative import SymmetricFunctionAlgebra_multiplicative
 
 

src/sage/combinat/sf/homogeneous.py

@@ -28,7 +28,7 @@
 ####################################
 from sage.arith.misc import binomial, factorial
 from sage.combinat.partition import Partition
-from sage.combinat.sf import multiplicative, classical
+from sage.combinat.sf import classical, multiplicative
 from sage.misc.misc_c import prod
 from sage.rings.infinity import infinity
 
@@ -310,7 +310,9 @@ def get_variable(ring, name):
                 try:
                     ring(name)
                 except TypeError:
-                    from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
+                    from sage.rings.polynomial.polynomial_ring_constructor import (
+                        PolynomialRing,
+                    )
                     return PolynomialRing(ring, name).gen()
                 else:
                     raise ValueError("the variable %s is in the base ring, pass it explicitly" % name)
@@ -413,7 +415,9 @@ def get_variable(ring, name):
                 try:
                     ring(name)
                 except TypeError:
-                    from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
+                    from sage.rings.polynomial.polynomial_ring_constructor import (
+                        PolynomialRing,
+                    )
                     return PolynomialRing(ring, name).gen()
                 else:
                     raise ValueError("the variable %s is in the base ring, pass it explicitly" % name)
@@ -453,6 +457,7 @@ def f(partition):
 
 # Backward compatibility for unpickling
 from sage.misc.persist import register_unpickle_override
+
 register_unpickle_override('sage.combinat.sf.homogeneous',
                            'SymmetricFunctionAlgebraElement_homogeneous',
                            SymmetricFunctionAlgebra_homogeneous.Element)

src/sage/combinat/sf/jack.py

@@ -30,17 +30,17 @@
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from sage.structure.unique_representation import UniqueRepresentation
 import sage.categories.all
-from sage.rings.integer import Integer
-from sage.rings.rational_field import QQ
-from sage.arith.misc import gcd
 from sage.arith.functions import lcm
-from sage.rings.fraction_field import FractionField_generic
-from sage.misc.misc_c import prod
+from sage.arith.misc import gcd
+from sage.categories.homset import End, Hom
 from sage.categories.morphism import SetMorphism
-from sage.categories.homset import Hom, End
-from sage.rings.fraction_field import FractionField
+from sage.misc.misc_c import prod
+from sage.rings.fraction_field import FractionField, FractionField_generic
+from sage.rings.integer import Integer
+from sage.rings.rational_field import QQ
+from sage.structure.unique_representation import UniqueRepresentation
+
 from . import sfa
 
 QQt = FractionField(QQ['t'])
@@ -1415,6 +1415,7 @@ def scalar_zonal(self, x):
 
 # Backward compatibility for unpickling
 from sage.misc.persist import register_unpickle_override
+
 register_unpickle_override('sage.combinat.sf.jack', 'JackPolynomial_qp', JackPolynomials_qp.Element)
 register_unpickle_override('sage.combinat.sf.jack', 'JackPolynomial_j', JackPolynomials_j.Element)
 register_unpickle_override('sage.combinat.sf.jack', 'JackPolynomial_p', JackPolynomials_p.Element)

src/sage/combinat/sf/k_dual.py

@@ -30,18 +30,23 @@
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from sage.structure.parent import Parent
-from sage.structure.unique_representation import UniqueRepresentation
 from sage.categories.graded_hopf_algebras import GradedHopfAlgebras
-from sage.combinat.partition import Partition, Partitions, Partitions_all_bounded, PartitionsGreatestLE
+from sage.categories.graded_hopf_algebras_with_basis import GradedHopfAlgebrasWithBasis
+from sage.categories.realizations import Category_realization_of_parent, Realizations
 from sage.combinat.free_module import CombinatorialFreeModule
-from sage.categories.realizations import Realizations, Category_realization_of_parent
+from sage.combinat.partition import (
+    Partition,
+    Partitions,
+    Partitions_all_bounded,
+    PartitionsGreatestLE,
+)
+from sage.cpython.getattr import raw_getattr
 from sage.misc.cachefunc import cached_method
 from sage.misc.constant_function import ConstantFunction
-from sage.categories.graded_hopf_algebras_with_basis import GradedHopfAlgebrasWithBasis
 from sage.rings.integer import Integer
 from sage.rings.integer_ring import ZZ
-from sage.cpython.getattr import raw_getattr
+from sage.structure.parent import Parent
+from sage.structure.unique_representation import UniqueRepresentation
 
 
 class KBoundedQuotient(UniqueRepresentation, Parent):