diff --git a/src/sage/combinat/cluster_algebra_quiver/mutation_class.py b/src/sage/combinat/cluster_algebra_quiver/mutation_class.py
index f8954fcc00d..54b58e568db 100644
--- a/src/sage/combinat/cluster_algebra_quiver/mutation_class.py
+++ b/src/sage/combinat/cluster_algebra_quiver/mutation_class.py
@@ -22,7 +22,7 @@
 from sage.groups.perm_gps.partn_ref.refinement_graphs import search_tree, get_orbits
 from sage.rings.integer_ring import ZZ
 from sage.rings.infinity import infinity
-from sage.graphs.all import DiGraph
+from sage.graphs.digraph import DiGraph
 from sage.combinat.cluster_algebra_quiver.quiver_mutation_type import _edge_list_to_matrix
 
 
diff --git a/src/sage/combinat/cluster_algebra_quiver/mutation_type.py b/src/sage/combinat/cluster_algebra_quiver/mutation_type.py
index 181e911c43d..66279cdb9a9 100644
--- a/src/sage/combinat/cluster_algebra_quiver/mutation_type.py
+++ b/src/sage/combinat/cluster_algebra_quiver/mutation_type.py
@@ -27,8 +27,8 @@
 
 from sage.misc.cachefunc import cached_function
 from sage.misc.flatten import flatten
-from sage.graphs.all import DiGraph
-from sage.combinat.all import Combinations
+from sage.graphs.digraph import DiGraph
+from sage.combinat.combination import Combinations
 from sage.combinat.cluster_algebra_quiver.quiver_mutation_type import QuiverMutationType
 
 
diff --git a/src/sage/combinat/cluster_algebra_quiver/quiver.py b/src/sage/combinat/cluster_algebra_quiver/quiver.py
index 4766fa71d2c..b12e94f45a5 100644
--- a/src/sage/combinat/cluster_algebra_quiver/quiver.py
+++ b/src/sage/combinat/cluster_algebra_quiver/quiver.py
@@ -42,7 +42,8 @@
 from sage.rings.integer_ring import ZZ
 from sage.rings.cc import CC
 from sage.rings.infinity import infinity
-from sage.graphs.all import Graph, DiGraph
+from sage.graphs.digraph import DiGraph
+from sage.graphs.graph import Graph
 from sage.graphs.views import EdgesView
 from sage.arith.misc import gcd
 from sage.modules.free_module_element import vector
diff --git a/src/sage/combinat/cluster_algebra_quiver/quiver_mutation_type.py b/src/sage/combinat/cluster_algebra_quiver/quiver_mutation_type.py
index 8925dc6d17b..53492d688d7 100644
--- a/src/sage/combinat/cluster_algebra_quiver/quiver_mutation_type.py
+++ b/src/sage/combinat/cluster_algebra_quiver/quiver_mutation_type.py
@@ -25,7 +25,8 @@
 from sage.misc.cachefunc import cached_method
 from sage.rings.integer_ring import ZZ
 from sage.rings.infinity import infinity
-from sage.graphs.all import Graph, DiGraph
+from sage.graphs.digraph import DiGraph
+from sage.graphs.graph import Graph
 from sage.arith.all import binomial, euler_phi
 from sage.misc.misc_c import prod
 from sage.matrix.constructor import matrix
diff --git a/src/sage/combinat/cluster_complex.py b/src/sage/combinat/cluster_complex.py
index ba5645b14ca..31562e6bc80 100644
--- a/src/sage/combinat/cluster_complex.py
+++ b/src/sage/combinat/cluster_complex.py
@@ -50,7 +50,7 @@
 from sage.categories.coxeter_groups import CoxeterGroups
 from sage.combinat.root_system.coxeter_group import CoxeterGroup
 from sage.combinat.subword_complex import SubwordComplex, SubwordComplexFacet
-from sage.rings.semirings.non_negative_integer_semiring import NN
+from sage.rings.semirings.all import NN
 
 
 class ClusterComplexFacet(SubwordComplexFacet):
diff --git a/src/sage/combinat/combinat.py b/src/sage/combinat/combinat.py
index a533a3c952a..610b54622cf 100644
--- a/src/sage/combinat/combinat.py
+++ b/src/sage/combinat/combinat.py
@@ -417,7 +417,7 @@ def bell_number(n, algorithm='flint', **options) -> Integer:
                 break
             b += v
             k += si
-        from sage.rings.all import RealField
+        from sage.rings.real_mpfr import RealField
         R = RealField(b.exact_log(2) + 1, rnd='RNDD')
         return ((R(-1).exp() / q) * b).ceil()
 
diff --git a/src/sage/combinat/combination.py b/src/sage/combinat/combination.py
index 7936bbc3516..f6d5a2a1860 100644
--- a/src/sage/combinat/combination.py
+++ b/src/sage/combinat/combination.py
@@ -26,7 +26,8 @@
 # ****************************************************************************
 import itertools
 
-from sage.rings.all import ZZ, Integer
+from sage.rings.integer import Integer
+from sage.rings.integer_ring import ZZ
 from sage.arith.all import binomial
 from .integer_vector import IntegerVectors
 from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets
diff --git a/src/sage/combinat/crystals/alcove_path.py b/src/sage/combinat/crystals/alcove_path.py
index 6ef9d20720d..4c0303c7a1d 100644
--- a/src/sage/combinat/crystals/alcove_path.py
+++ b/src/sage/combinat/crystals/alcove_path.py
@@ -8,10 +8,9 @@
 - Travis Scrimshaw (2016-06-23): implemented `\mathcal{B}(\infty)`
 
 Special thanks to: Nicolas Borie, Anne Schilling, Travis Scrimshaw, and
-Nicolas Thiery.
+Nicolas Thiéry.
 """
-
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2008 Brant Jones <brant at math.ucdavis.edu>
 #       Copyright (C) 2013 Arthur Lubovsky <alubovsky at albany.edu>
 #
@@ -19,8 +18,8 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from sage.structure.parent import Parent
 from sage.structure.element import Element
@@ -29,7 +28,7 @@
 from sage.structure.richcmp import richcmp
 from sage.categories.classical_crystals import ClassicalCrystals
 from sage.categories.loop_crystals import LoopCrystals
-from sage.graphs.all import DiGraph
+from sage.graphs.digraph import DiGraph
 from sage.combinat.root_system.cartan_type import CartanType
 from sage.combinat.root_system.root_system import RootSystem
 from sage.all import vector
diff --git a/src/sage/combinat/crystals/crystals.py b/src/sage/combinat/crystals/crystals.py
index b7288753fba..0b3fa3998df 100644
--- a/src/sage/combinat/crystals/crystals.py
+++ b/src/sage/combinat/crystals/crystals.py
@@ -155,20 +155,14 @@
 #  The full text of the GPL is available at:
 #
 #                  http://www.gnu.org/licenses/
-#****************************************************************************
+# ***************************************************************************
 # Acknowledgment: most of the design and implementation of this
 # library is heavily inspired from MuPAD-Combinat.
-#****************************************************************************
-
-#from sage.structure.unique_representation import UniqueRepresentation
-#from sage.structure.parent import Parent
-#from sage.structure.element import Element
-#from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets
-#from sage.graphs.all import DiGraph
-#from sage.combinat import ranker
-#from sage.combinat.root_system.weyl_characters import WeylCharacter
+# ***************************************************************************
+
 from sage.combinat.backtrack import GenericBacktracker
 
+
 class CrystalBacktracker(GenericBacktracker):
     def __init__(self, crystal, index_set=None):
         r"""
diff --git a/src/sage/combinat/crystals/tensor_product.py b/src/sage/combinat/crystals/tensor_product.py
index 4b8ee8480d8..7cacfeb335b 100644
--- a/src/sage/combinat/crystals/tensor_product.py
+++ b/src/sage/combinat/crystals/tensor_product.py
@@ -51,7 +51,7 @@
         TensorProductOfSuperCrystalsElement, TensorProductOfQueerSuperCrystalsElement)
 from sage.misc.flatten import flatten
 from sage.structure.element import get_coercion_model
-from sage.rings.semirings.non_negative_integer_semiring import NN
+from sage.rings.semirings.all import NN
 from sage.arith.misc import integer_trunc as trunc
 
 
diff --git a/src/sage/combinat/integer_lists/nn.py b/src/sage/combinat/integer_lists/nn.py
index 4329c6164d9..6fe0cb0adb5 100644
--- a/src/sage/combinat/integer_lists/nn.py
+++ b/src/sage/combinat/integer_lists/nn.py
@@ -1,6 +1,6 @@
 from sage.sets.family import Family
 from sage.combinat.integer_lists import IntegerListsLex
-from sage.rings.semirings.non_negative_integer_semiring import NN
+from sage.rings.semirings.all import NN
 from sage.sets.disjoint_union_enumerated_sets import DisjointUnionEnumeratedSets
 
 
diff --git a/src/sage/combinat/interval_posets.py b/src/sage/combinat/interval_posets.py
index d698ef689ad..129709c82cb 100644
--- a/src/sage/combinat/interval_posets.py
+++ b/src/sage/combinat/interval_posets.py
@@ -48,7 +48,7 @@
 from sage.misc.latex import latex
 from sage.misc.lazy_attribute import lazy_attribute
 from sage.rings.integer import Integer
-from sage.rings.all import NN
+from sage.rings.semirings.all import NN
 from sage.sets.non_negative_integers import NonNegativeIntegers
 from sage.sets.disjoint_union_enumerated_sets import DisjointUnionEnumeratedSets
 from sage.sets.family import Family
diff --git a/src/sage/combinat/non_decreasing_parking_function.py b/src/sage/combinat/non_decreasing_parking_function.py
index cea50974f0c..b5ecf2bb8c0 100644
--- a/src/sage/combinat/non_decreasing_parking_function.py
+++ b/src/sage/combinat/non_decreasing_parking_function.py
@@ -38,7 +38,7 @@
 from sage.categories.infinite_enumerated_sets import InfiniteEnumeratedSets
 from sage.categories.sets_with_grading import SetsWithGrading
 from sage.categories.monoids import Monoids
-from sage.rings.all import NN
+from sage.rings.semirings.all import NN
 from sage.rings.integer import Integer
 from sage.structure.element import Element
 from sage.structure.parent import Parent
diff --git a/src/sage/combinat/partition.py b/src/sage/combinat/partition.py
index 5b7ce2022de..1d1ae54b5d7 100644
--- a/src/sage/combinat/partition.py
+++ b/src/sage/combinat/partition.py
@@ -305,7 +305,10 @@
 from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets
 
 from sage.sets.non_negative_integers import NonNegativeIntegers
-from sage.rings.all import QQ, ZZ, NN, IntegerModRing
+from sage.rings.finite_rings.integer_mod_ring import IntegerModRing
+from sage.rings.integer_ring import ZZ
+from sage.rings.rational_field import QQ
+from sage.rings.semirings.all import NN
 from sage.arith.all import factorial, gcd
 from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
 from sage.rings.integer import Integer
diff --git a/src/sage/combinat/partition_kleshchev.py b/src/sage/combinat/partition_kleshchev.py
index 093eabf8a3a..cad6332374a 100644
--- a/src/sage/combinat/partition_kleshchev.py
+++ b/src/sage/combinat/partition_kleshchev.py
@@ -83,7 +83,9 @@
 from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets
 from sage.categories.infinite_enumerated_sets import InfiniteEnumeratedSets
 from sage.misc.lazy_attribute import lazy_attribute
-from sage.rings.all import NN, ZZ, IntegerModRing
+from sage.rings.finite_rings.integer_mod_ring import IntegerModRing
+from sage.rings.integer_ring import ZZ
+from sage.rings.semirings.all import NN
 from sage.cpython.getattr import getattr_from_other_class
 
 from collections import defaultdict
diff --git a/src/sage/combinat/partition_shifting_algebras.py b/src/sage/combinat/partition_shifting_algebras.py
index 7395fdd4776..f632e769ef8 100644
--- a/src/sage/combinat/partition_shifting_algebras.py
+++ b/src/sage/combinat/partition_shifting_algebras.py
@@ -28,7 +28,8 @@
 from sage.combinat.sf.sf import SymmetricFunctions
 from sage.misc.fast_methods import Singleton
 from sage.misc.cachefunc import cached_method
-from sage.rings.all import QQ, NonNegativeIntegerSemiring
+from sage.rings.rational_field import QQ
+from sage.rings.semirings.non_negative_integer_semiring import NonNegativeIntegerSemiring
 from sage.rings.integer_ring import ZZ
 
 
diff --git a/src/sage/combinat/partition_tuple.py b/src/sage/combinat/partition_tuple.py
index 56f9290b17e..c5febd95569 100644
--- a/src/sage/combinat/partition_tuple.py
+++ b/src/sage/combinat/partition_tuple.py
@@ -265,7 +265,9 @@ class of modules for the algebras, which are generalisations of the Specht
 from sage.groups.perm_gps.permgroup import PermutationGroup
 from sage.libs.pari.all import pari
 from sage.misc.cachefunc import cached_method
-from sage.rings.all import NN, ZZ, IntegerModRing
+from sage.rings.finite_rings.integer_mod_ring import IntegerModRing
+from sage.rings.integer_ring import ZZ
+from sage.rings.semirings.all import NN
 from sage.rings.integer import Integer
 from sage.sets.positive_integers import PositiveIntegers
 from sage.structure.parent import Parent
diff --git a/src/sage/combinat/path_tableaux/semistandard.py b/src/sage/combinat/path_tableaux/semistandard.py
index 98b9d3905fa..3aa0dc1937d 100644
--- a/src/sage/combinat/path_tableaux/semistandard.py
+++ b/src/sage/combinat/path_tableaux/semistandard.py
@@ -85,10 +85,11 @@
 from sage.combinat.tableau import Tableau
 from sage.combinat.gelfand_tsetlin_patterns import GelfandTsetlinPattern
 from sage.combinat.partition import _Partitions
-from sage.rings.all import NN
+from sage.rings.semirings.all import NN
 
 ###############################################################################
 
+
 class SemistandardPathTableau(PathTableau):
     r"""
     An instance is a sequence of lists. Usually the entries will be non-negative integers
diff --git a/src/sage/combinat/permutation.py b/src/sage/combinat/permutation.py
index cf053311550..bdc4c30cd2e 100644
--- a/src/sage/combinat/permutation.py
+++ b/src/sage/combinat/permutation.py
@@ -246,7 +246,9 @@
 from sage.structure.list_clone import ClonableArray
 from sage.structure.global_options import GlobalOptions
 from sage.libs.gap.libgap import libgap
-from sage.rings.all import ZZ, Integer, PolynomialRing
+from sage.rings.integer import Integer
+from sage.rings.integer_ring import ZZ
+from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
 from sage.arith.all import factorial, multinomial
 from sage.matrix.matrix_space import MatrixSpace
 from sage.combinat.tools import transitive_ideal
@@ -7503,7 +7505,7 @@ def bistochastic_as_sum_of_permutations(M, check = True):
     """
     from sage.graphs.bipartite_graph import BipartiteGraph
     from sage.combinat.free_module import CombinatorialFreeModule
-    from sage.rings.all import RR
+    from sage.rings.real_mpfr import RR
 
     n = M.nrows()
 
diff --git a/src/sage/combinat/posets/poset_examples.py b/src/sage/combinat/posets/poset_examples.py
index f47310ccb35..18251fde9fd 100644
--- a/src/sage/combinat/posets/poset_examples.py
+++ b/src/sage/combinat/posets/poset_examples.py
@@ -612,7 +612,7 @@ def IntegerPartitionsDominanceOrder(n):
              [[4, 2], [5, 1]],
              [[5, 1], [6]]]
         """
-        from sage.rings.semirings.non_negative_integer_semiring import NN
+        from sage.rings.semirings.all import NN
         if n not in NN:
             raise ValueError('n must be an integer')
         from sage.combinat.partition import Partitions, Partition
@@ -963,7 +963,7 @@ def SetPartitions(n):
             sage: posets.SetPartitions(4)
             Finite lattice containing 15 elements
         """
-        from sage.rings.semirings.non_negative_integer_semiring import NN
+        from sage.rings.semirings.all import NN
         if n not in NN:
             raise ValueError('n must be an integer')
         from sage.combinat.set_partition import SetPartitions
diff --git a/src/sage/combinat/root_system/cartan_type.py b/src/sage/combinat/root_system/cartan_type.py
index 6bdee48235f..26781f566c6 100644
--- a/src/sage/combinat/root_system/cartan_type.py
+++ b/src/sage/combinat/root_system/cartan_type.py
@@ -594,7 +594,7 @@ def __call__(self, *args):
         if isinstance(t, (CartanType_abstract, SuperCartanType_standard)):
             return t
 
-        from sage.rings.semirings.non_negative_integer_semiring import NN
+        from sage.rings.semirings.all import NN
         if isinstance(t, str):
             if "x" in t:
                 from . import type_reducible
diff --git a/src/sage/combinat/root_system/coxeter_matrix.py b/src/sage/combinat/root_system/coxeter_matrix.py
index 2595166bf57..63d153d7281 100644
--- a/src/sage/combinat/root_system/coxeter_matrix.py
+++ b/src/sage/combinat/root_system/coxeter_matrix.py
@@ -24,7 +24,9 @@
 from sage.misc.classcall_metaclass import ClasscallMetaclass, typecall
 from sage.matrix.matrix_generic_dense import Matrix_generic_dense
 from sage.graphs.graph import Graph
-from sage.rings.all import ZZ, QQ, RR
+from sage.rings.integer_ring import ZZ
+from sage.rings.rational_field import QQ
+from sage.rings.real_mpfr import RR
 from sage.rings.infinity import infinity
 from sage.combinat.root_system.cartan_type import CartanType
 from sage.combinat.root_system.coxeter_type import CoxeterType
diff --git a/src/sage/combinat/root_system/root_lattice_realizations.py b/src/sage/combinat/root_system/root_lattice_realizations.py
index 377ce53376c..fafaa9fa82f 100644
--- a/src/sage/combinat/root_system/root_lattice_realizations.py
+++ b/src/sage/combinat/root_system/root_lattice_realizations.py
@@ -3833,7 +3833,7 @@ def is_dominant_weight(self): # Or is_dominant_integral_weight?
                True
             """
             alphacheck = self.parent().simple_coroots()
-            from sage.rings.semirings.non_negative_integer_semiring import NN
+            from sage.rings.semirings.all import NN
             return all(self.inner_product(alphacheck[i]) in NN
                        for i in self.parent().index_set())
 
diff --git a/src/sage/combinat/root_system/type_super_A.py b/src/sage/combinat/root_system/type_super_A.py
index 1bbbbfdcbff..d77b82d6782 100644
--- a/src/sage/combinat/root_system/type_super_A.py
+++ b/src/sage/combinat/root_system/type_super_A.py
@@ -442,7 +442,7 @@ def is_dominant_weight(self):
             """
             alpha = self.parent().simple_roots()
             l = self.parent().cartan_type().symmetrizer()
-            from sage.rings.semirings.non_negative_integer_semiring import NN
+            from sage.rings.semirings.all import NN
             return all(l[i] * self.inner_product(alpha[i]) in NN
                        for i in self.parent().index_set())
 
diff --git a/src/sage/combinat/schubert_polynomial.py b/src/sage/combinat/schubert_polynomial.py
index c01bd684c61..af28a8e45d7 100644
--- a/src/sage/combinat/schubert_polynomial.py
+++ b/src/sage/combinat/schubert_polynomial.py
@@ -17,7 +17,9 @@
 # ****************************************************************************
 from sage.combinat.free_module import CombinatorialFreeModule
 from sage.categories.all import GradedAlgebrasWithBasis
-from sage.rings.all import Integer, PolynomialRing, ZZ
+from sage.rings.integer import Integer
+from sage.rings.integer_ring import ZZ
+from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
 from sage.rings.polynomial.multi_polynomial import is_MPolynomial
 from sage.combinat.permutation import Permutations, Permutation
 import sage.libs.symmetrica.all as symmetrica
diff --git a/src/sage/combinat/sf/jack.py b/src/sage/combinat/sf/jack.py
index 5ca78639572..d0c46d29ccc 100644
--- a/src/sage/combinat/sf/jack.py
+++ b/src/sage/combinat/sf/jack.py
@@ -18,8 +18,7 @@
    The Clarendon Press, Oxford University Press, New York, 1995, With contributions
    by A. Zelevinsky, Oxford Science Publications.
 """
-
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2007 Mike Hansen <mhansen@gmail.com>
 #                     2012 Mike Zabrocki <mike.zabrocki@gmail.com>
 #
@@ -27,12 +26,13 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from sage.structure.unique_representation import UniqueRepresentation
 import sage.categories.all
-from sage.rings.all import Integer, QQ
+from sage.rings.integer import Integer
+from sage.rings.rational_field import QQ
 from sage.arith.all import gcd, lcm
 from sage.rings.fraction_field import is_FractionField
 from sage.misc.misc_c import prod
diff --git a/src/sage/combinat/sf/k_dual.py b/src/sage/combinat/sf/k_dual.py
index 65f27bf7be0..6e41c90affc 100644
--- a/src/sage/combinat/sf/k_dual.py
+++ b/src/sage/combinat/sf/k_dual.py
@@ -12,7 +12,7 @@
 
 - Mike Zabrocki - `k`-bounded Hall Littlewood P and dual `k`-Schur functions (2012-12-02)
 """
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2012 Chris Berg <chrisjamesberg@gmail.com>
 #       Based off of similar code of Jason Bandlow, Anne Schilling
 #                                    and Mike Zabrocki
@@ -26,8 +26,8 @@
 #
 #  The full text of the GPL is available at:
 #
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from sage.structure.parent import Parent
 from sage.structure.unique_representation import UniqueRepresentation
@@ -38,7 +38,8 @@
 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.all import Integer, ZZ
+from sage.rings.integer import Integer
+from sage.rings.integer_ring import ZZ
 from sage.cpython.getattr import raw_getattr
 
 
diff --git a/src/sage/combinat/sf/new_kschur.py b/src/sage/combinat/sf/new_kschur.py
index bc7da8cd621..d40aee2d92e 100644
--- a/src/sage/combinat/sf/new_kschur.py
+++ b/src/sage/combinat/sf/new_kschur.py
@@ -16,7 +16,8 @@
 #
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
-from sage.rings.all import Integer, ZZ
+from sage.rings.integer import Integer
+from sage.rings.integer_ring import ZZ
 from sage.structure.unique_representation import UniqueRepresentation
 from sage.structure.parent import Parent
 from sage.categories.realizations import Realizations, Category_realization_of_parent
diff --git a/src/sage/combinat/sf/ns_macdonald.py b/src/sage/combinat/sf/ns_macdonald.py
index a6d9420a5da..c36a0fd99a9 100644
--- a/src/sage/combinat/sf/ns_macdonald.py
+++ b/src/sage/combinat/sf/ns_macdonald.py
@@ -7,7 +7,8 @@
 from sage.combinat.words.word import Word
 from sage.combinat.combination import Combinations
 from sage.combinat.permutation import Permutation
-from sage.rings.all import QQ, PolynomialRing
+from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
+from sage.rings.rational_field import QQ
 from sage.misc.misc_c import prod
 from sage.combinat.backtrack import GenericBacktracker
 from sage.structure.parent import Parent
diff --git a/src/sage/combinat/similarity_class_type.py b/src/sage/combinat/similarity_class_type.py
index a77f5b65bca..7cd8fd3ab56 100644
--- a/src/sage/combinat/similarity_class_type.py
+++ b/src/sage/combinat/similarity_class_type.py
@@ -186,7 +186,9 @@ class type, it is also possible to compute the number of classes of that type
 from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets
 from sage.combinat.combinat import CombinatorialElement
 from sage.combinat.partition import Partitions, Partition
-from sage.rings.all import ZZ, QQ, FractionField
+from sage.rings.fraction_field import FractionField
+from sage.rings.integer_ring import ZZ
+from sage.rings.rational_field import QQ
 from sage.misc.cachefunc import cached_in_parent_method, cached_function
 from sage.combinat.misc import IterableFunctionCall
 
diff --git a/src/sage/combinat/sine_gordon.py b/src/sage/combinat/sine_gordon.py
index 8cdd49e8364..ff5f1ae20b5 100644
--- a/src/sage/combinat/sine_gordon.py
+++ b/src/sage/combinat/sine_gordon.py
@@ -31,23 +31,24 @@
 .. [NS] \T. Nakanishi, S. Stella, Wonder of sine-Gordon Y-systems,
    to appear in Trans. Amer. Math. Soc., :arxiv:`1212.6853`
 """
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2014 Salvatore Stella <sstella@ncsu.edu>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from sage.structure.sage_object import SageObject
 
 from sage.rings.integer_ring import ZZ
 from sage.rings.real_mpfr import RR
-from sage.rings.all import NN
+from sage.rings.semirings.all import NN
 from sage.misc.lazy_import import lazy_import
 lazy_import("sage.functions.trig", "cos", "sin")
+from sage.functions.trig import cos, sin
 from sage.plot.plot import parametric_plot
 from sage.plot.graphics import Graphics
 from sage.plot.polygon import polygon2d
@@ -55,16 +56,11 @@
 from sage.plot.bezier_path import bezier_path
 from sage.plot.point import point
 from sage.plot.line import line
-from sage.misc.lazy_import import lazy_import
 lazy_import("sage.symbolic.constants", "pi", "I")
-from sage.misc.lazy_import import lazy_import
 lazy_import("sage.functions.log", "exp")
-from sage.misc.lazy_import import lazy_import
 lazy_import("sage.functions.other", "ceil")
 from sage.misc.flatten import flatten
-from sage.misc.lazy_import import lazy_import
 lazy_import("sage.symbolic.ring", "SR")
-from sage.misc.lazy_import import lazy_import
 lazy_import("sage.functions.other", "real_part", "imag_part")
 from sage.misc.cachefunc import cached_method
 
diff --git a/src/sage/combinat/skew_tableau.py b/src/sage/combinat/skew_tableau.py
index 676aff61440..906b86f2930 100644
--- a/src/sage/combinat/skew_tableau.py
+++ b/src/sage/combinat/skew_tableau.py
@@ -32,7 +32,9 @@
 from sage.categories.infinite_enumerated_sets import InfiniteEnumeratedSets
 from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets
 
-from sage.rings.all import Integer, QQ, ZZ
+from sage.rings.integer import Integer
+from sage.rings.integer_ring import ZZ
+from sage.rings.rational_field import QQ
 from sage.arith.all import factorial
 from sage.rings.infinity import PlusInfinity
 from sage.matrix.all import zero_matrix
diff --git a/src/sage/combinat/species/generating_series.py b/src/sage/combinat/species/generating_series.py
index bd57b4cd572..77749fc79b7 100644
--- a/src/sage/combinat/species/generating_series.py
+++ b/src/sage/combinat/species/generating_series.py
@@ -63,23 +63,24 @@
 .. [BLL] \F. Bergeron, G. Labelle, and P. Leroux.
    "Combinatorial species and tree-like structures".
    Encyclopedia of Mathematics and its Applications, vol. 67, Cambridge Univ. Press. 1998.
-.. [BLL-Intro] Francois Bergeron, Gilbert Labelle, and Pierre Leroux.
+.. [BLL-Intro] François Bergeron, Gilbert Labelle, and Pierre Leroux.
    "Introduction to the Theory of Species of Structures", March 14, 2008.
 """
 
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2008 Mike Hansen <mhansen@gmail.com>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from .series import LazyPowerSeriesRing, LazyPowerSeries
 from .stream import Stream, _integers_from
-from sage.rings.all import Integer, RationalField
+from sage.rings.integer import Integer
+from sage.rings.rational_field import RationalField
 from sage.arith.all import moebius, gcd, lcm, divisors
 from sage.combinat.partition import Partition, Partitions
 from functools import partial
diff --git a/src/sage/combinat/symmetric_group_algebra.py b/src/sage/combinat/symmetric_group_algebra.py
index 6263dfea7cb..7ac314bd934 100644
--- a/src/sage/combinat/symmetric_group_algebra.py
+++ b/src/sage/combinat/symmetric_group_algebra.py
@@ -19,7 +19,8 @@
 from sage.combinat.tableau import Tableau, StandardTableaux_size, StandardTableaux_shape, StandardTableaux
 from sage.algebras.group_algebra import GroupAlgebra_class
 from sage.categories.weyl_groups import WeylGroups
-from sage.rings.all import QQ, PolynomialRing
+from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
+from sage.rings.rational_field import QQ
 from sage.arith.all import factorial
 from sage.matrix.constructor import matrix
 from sage.modules.free_module_element import vector
@@ -214,7 +215,7 @@ def SymmetricGroupAlgebra(R, W, category=None):
         sage: SGg.group().conjugacy_classes_representatives()
         [(), (1,2), (1,2,3)]
     """
-    from sage.rings.semirings.non_negative_integer_semiring import NN
+    from sage.rings.semirings.all import NN
     if W in NN:
         W = Permutations(W)
     if category is None:
diff --git a/src/sage/combinat/tableau_tuple.py b/src/sage/combinat/tableau_tuple.py
index a7b98a63743..35804c7adcb 100644
--- a/src/sage/combinat/tableau_tuple.py
+++ b/src/sage/combinat/tableau_tuple.py
@@ -231,7 +231,7 @@
 from sage.arith.all import factorial
 from sage.rings.finite_rings.integer_mod_ring import IntegerModRing
 from sage.rings.integer import Integer
-from sage.rings.all import NN
+from sage.rings.semirings.all import NN
 from sage.sets.disjoint_union_enumerated_sets import DisjointUnionEnumeratedSets
 from sage.sets.family import Family
 from sage.sets.positive_integers import PositiveIntegers
diff --git a/src/sage/combinat/words/abstract_word.py b/src/sage/combinat/words/abstract_word.py
index 33261cad6f2..beb05eb21a8 100644
--- a/src/sage/combinat/words/abstract_word.py
+++ b/src/sage/combinat/words/abstract_word.py
@@ -30,13 +30,14 @@
 # (at your option) any later version.
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
+from itertools import islice, groupby
 
 from sage.structure.sage_object import SageObject
 from sage.combinat.words.word_options import word_options
-from itertools import islice, groupby
-from sage.rings.all import Integers, ZZ, Infinity
-from sage.structure.richcmp import (richcmp_method, rich_to_bool,
-                                    richcmp_item)
+from sage.rings.finite_rings.integer_mod_ring import Integers
+from sage.rings.infinity import Infinity
+from sage.rings.integer_ring import ZZ
+from sage.structure.richcmp import richcmp_method, rich_to_bool, richcmp_item
 
 
 @richcmp_method
@@ -832,7 +833,7 @@ def delta(self):
             word: 1211222112112112221122211222112112112221...
         """
         from sage.combinat.words.word import Word
-        from sage.rings.semirings.non_negative_integer_semiring import NN
+        from sage.rings.semirings.all import NN
         return Word(self._delta_iterator(), alphabet=NN)
 
     def _iterated_right_palindromic_closure_iterator(self, f=None):
diff --git a/src/sage/combinat/words/finite_word.py b/src/sage/combinat/words/finite_word.py
index 7cdc289a290..fd589624796 100644
--- a/src/sage/combinat/words/finite_word.py
+++ b/src/sage/combinat/words/finite_word.py
@@ -202,7 +202,7 @@
     sage: f.bispecial_factors()
     [word: , word: 0, word: 010, word: 010010, word: 01001010010]
 """
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2008 Arnaud Bergeron <abergeron@gmail.com>,
 #                     2008 Amy Glen <amy.glen@gmail.com>,
 #                     2008-2012 Sébastien Labbé <slabqc@gmail.com>,
@@ -212,8 +212,8 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from collections import defaultdict
 from itertools import islice, cycle
@@ -221,9 +221,13 @@
 from sage.combinat.words.words import Words
 from sage.misc.cachefunc import cached_method
 from sage.combinat.words.word_options import word_options
-from sage.rings.all import Integer, Infinity, ZZ, QQ
+from sage.rings.infinity import Infinity
+from sage.rings.integer import Integer
+from sage.rings.integer_ring import ZZ
+from sage.rings.rational_field import QQ
 from sage.sets.set import Set
 
+
 class FiniteWord_class(Word_class):
     def __str__(self):
         r"""
diff --git a/src/sage/combinat/words/infinite_word.py b/src/sage/combinat/words/infinite_word.py
index dc547c5ddaf..db8f15d577e 100644
--- a/src/sage/combinat/words/infinite_word.py
+++ b/src/sage/combinat/words/infinite_word.py
@@ -75,7 +75,7 @@
 # ****************************************************************************
 from sage.combinat.words.abstract_word import Word_class
 from sage.combinat.words.word_options import word_options
-from sage.rings.all import Infinity
+from sage.rings.infinity import Infinity
 
 
 class InfiniteWord_class(Word_class):
diff --git a/src/sage/combinat/words/morphic.py b/src/sage/combinat/words/morphic.py
index 3fbbe48f26b..5ff1befeebd 100644
--- a/src/sage/combinat/words/morphic.py
+++ b/src/sage/combinat/words/morphic.py
@@ -30,9 +30,10 @@
 """
 
 from sage.combinat.words.word_infinite_datatypes import WordDatatype_callable
-from sage.rings.all import Infinity
+from sage.rings.infinity import Infinity
 from sage.modules.free_module_element import vector
 
+
 class WordDatatype_morphic(WordDatatype_callable):
     r"""
     Datatype for a morphic word defined by a morphism, a starting letter
diff --git a/src/sage/combinat/words/paths.py b/src/sage/combinat/words/paths.py
index 902ba16ab54..9cf3483bedd 100644
--- a/src/sage/combinat/words/paths.py
+++ b/src/sage/combinat/words/paths.py
@@ -167,7 +167,7 @@
 - [5] :wikipedia:`Dyck_word`
 
 """
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2008 Arnaud bergeron <abergeron@gmail.coms>,
 #       Copyright (C) 2009 Sebastien Labbe <slabqc@gmail.com>,
 #
@@ -175,8 +175,8 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from builtins import zip
 
@@ -188,7 +188,9 @@
 from sage.combinat.words.alphabet import build_alphabet
 from sage.plot.all import arrow, line, polygon, point, Graphics
 from sage.modules.free_module_element import vector
-from sage.rings.all import ZZ, RR, QuadraticField
+from sage.rings.integer_ring import ZZ
+from sage.rings.number_field.number_field import QuadraticField
+from sage.rings.real_mpfr import RR
 from .word_datatypes import (WordDatatype_str,
                             WordDatatype_list,
                             WordDatatype_tuple)
diff --git a/src/sage/combinat/words/word_generators.py b/src/sage/combinat/words/word_generators.py
index 910dc30098e..18540ba241c 100644
--- a/src/sage/combinat/words/word_generators.py
+++ b/src/sage/combinat/words/word_generators.py
@@ -57,7 +57,8 @@
 from itertools import cycle, count
 from random import randint
 from sage.misc.cachefunc import cached_method
-from sage.rings.all import ZZ, RR
+from sage.rings.integer_ring import ZZ
+from sage.rings.real_mpfr import RR
 from sage.rings.infinity import Infinity
 from sage.combinat.words.abstract_word import Word_class
 from sage.combinat.words.word import FiniteWord_list
@@ -67,6 +68,7 @@
 from sage.arith.all import gcd
 from sage.misc.decorators import rename_keyword
 
+
 def _build_tab(sym, tab, W):
     r"""
     Internal function building a coding table for the ``phi_inv_tab`` function.
diff --git a/src/sage/combinat/words/word_infinite_datatypes.py b/src/sage/combinat/words/word_infinite_datatypes.py
index a42901cbc5a..95664b687af 100644
--- a/src/sage/combinat/words/word_infinite_datatypes.py
+++ b/src/sage/combinat/words/word_infinite_datatypes.py
@@ -1,7 +1,7 @@
 r"""
 Datatypes for words defined by iterators and callables
 """
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2009 Franco Saliola <saliola@gmail.com>
 #                          Vincent Delecroix <20100.delecroix@gmail.com>
 #
@@ -9,14 +9,15 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from sage.combinat.words.word_datatypes import WordDatatype
-from sage.rings.all import Infinity
+from sage.rings.infinity import Infinity
 from math import ceil
 import itertools
 
+
 class WordDatatype_callable(WordDatatype):
     r"""
     Datatype for a word defined by a callable.
diff --git a/src/sage/combinat/words/words.py b/src/sage/combinat/words/words.py
index 5a75921c47f..15bcf880ab4 100644
--- a/src/sage/combinat/words/words.py
+++ b/src/sage/combinat/words/words.py
@@ -54,7 +54,7 @@
 from sage.structure.list_clone import ClonableElement
 from sage.combinat.words.alphabet import build_alphabet
 
-from sage.rings.all import Infinity
+from sage.rings.infinity import Infinity
 from sage.rings.integer import Integer
 from sage.rings.integer_ring import ZZ