Release Manager · Release Manager · commit 202ccd7ea08f · 2023-06-08T00:34:42.000+02:00
gh-35733: more uses of yield from    ### 📚 Description a few more use cases for the cool syntax `yield from`     ### 📝 Checklist  - [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   URL: #35733 Reported by: Frédéric Chapoton Reviewer(s): Kwankyu Lee
diff --git a/src/sage/combinat/interval_posets.py b/src/sage/combinat/interval_posets.py
@@ -2146,31 +2146,26 @@ def add_relations(poset, n, m):
 
             if poset.le(n, m):
                 # there is already a link n->m, so we go to the next n
-                for pos in add_relations(poset, n - 1, m):
-                    yield pos
+                yield from add_relations(poset, n - 1, m)
             elif poset.le(m, n):
                 # there is an inverse link m->n, we know we won't be able
                 # to create a link i->m with i<=n, so we go to the next m
-                for pos in add_relations(poset, m, m + 1):
-                    yield pos
+                yield from add_relations(poset, m, m + 1)
             else:
                 # there is no link n->m
                 # first option : we don't create the link and go to the next m
                 # (since the lack of a link n->m forbids any links i->m
                 # with i<n)
-                for pos in add_relations(poset, m, m + 1):
-                    yield pos
+                yield from add_relations(poset, m, m + 1)
                 # second option : we create the link
                 # (this is allowed because links i->m already exist for all
                 # n<i<m, or else we wouldn't be here)
                 poset = TamariIntervalPoset(poset.size(), poset._cover_relations + ((n, m),))
                 yield poset
                 # and then, we go to the next n
-                for pos in add_relations(poset, n - 1, m):
-                    yield pos
+                yield from add_relations(poset, n - 1, m)
 
-        for inter in add_relations(self, 1, 2):
-            yield inter
+        yield from add_relations(self, 1, 2)
 
     def interval_cardinality(self) -> Integer:
         r"""
diff --git a/src/sage/combinat/necklace.py b/src/sage/combinat/necklace.py
@@ -295,8 +295,7 @@ def _ffc(content, equality=False):
     if not e[0]:  # == 0
         dll.hide(0)
 
-    for x in _fast_fixed_content(a, e, 2, 1, k, r, 2, dll, equality=equality):
-        yield x
+    yield from _fast_fixed_content(a, e, 2, 1, k, r, 2, dll, equality=equality)
 
 
 def _fast_fixed_content(a, content, t, p, k, r, s, dll, equality=False):
@@ -347,13 +346,13 @@ def _fast_fixed_content(a, content, t, p, k, r, s, dll, equality=False):
                 sp = t + 1
 
             if j == a[t - p - 1]:
-                for x in _fast_fixed_content(a[:], content, t + 1, p,
-                                             k, r, sp, dll, equality=equality):
-                    yield x
+                yield from _fast_fixed_content(a[:], content, t + 1, p,
+                                               k, r, sp, dll,
+                                               equality=equality)
             else:
-                for x in _fast_fixed_content(a[:], content, t + 1, t,
-                                             k, r, sp, dll, equality=equality):
-                    yield x
+                yield from _fast_fixed_content(a[:], content, t + 1, t,
+                                               k, r, sp, dll,
+                                               equality=equality)
 
             if not content[j]:  # == 0
                 dll.unhide(j)
@@ -392,8 +391,7 @@ def _lfc(content, equality=False):
     if not content[0]:  # == 0
         dll.hide(0)
 
-    for z in _list_fixed_content(a, content, 2, 1, k, dll, equality=equality):
-        yield z
+    yield from _list_fixed_content(a, content, 2, 1, k, dll, equality=equality)
 
 
 def _list_fixed_content(a, content, t, p, k, dll, equality=False):
@@ -434,13 +432,11 @@ def _list_fixed_content(a, content, t, p, k, dll, equality=False):
                 dll.hide(j)
 
             if j == a[t - p - 1]:
-                for z in _list_fixed_content(a[:], content[:], t + 1, p,
-                                             k, dll, equality=equality):
-                    yield z
+                yield from _list_fixed_content(a[:], content[:], t + 1, p,
+                                               k, dll, equality=equality)
             else:
-                for z in _list_fixed_content(a[:], content[:], t + 1, t,
-                                             k, dll, equality=equality):
-                    yield z
+                yield from _list_fixed_content(a[:], content[:], t + 1, t,
+                                               k, dll, equality=equality)
 
             if not content[j]:  # == 0
                 dll.unhide(j)
@@ -519,13 +515,11 @@ def _simple_fixed_content(a, content, t, p, k, equality=False):
                 a[t - 1] = j
                 content[j] -= 1
                 if j == a[t - p - 1]:
-                    for z in _simple_fixed_content(a[:], content, t + 1, p,
-                                                   k, equality=equality):
-                        yield z
+                    yield from _simple_fixed_content(a[:], content, t + 1, p,
+                                                     k, equality=equality)
                 else:
-                    for z in _simple_fixed_content(a[:], content, t + 1, t,
-                                                   k, equality=equality):
-                        yield z
+                    yield from _simple_fixed_content(a[:], content, t + 1, t,
+                                                     k, equality=equality)
                 content[j] += 1
 
 
diff --git a/src/sage/combinat/non_decreasing_parking_function.py b/src/sage/combinat/non_decreasing_parking_function.py
@@ -419,8 +419,7 @@ def __iter__(self):
             [[], [1], [1, 1], [1, 2], [1, 1, 1], [1, 1, 2], [1, 1, 3], [1, 2, 2]]
         """
         for n in NN:
-            for pf in NonDecreasingParkingFunctions_n(n):
-                yield pf
+            yield from NonDecreasingParkingFunctions_n(n)
 
     def graded_component(self, n):
         """
diff --git a/src/sage/combinat/posets/hasse_diagram.py b/src/sage/combinat/posets/hasse_diagram.py
@@ -889,8 +889,7 @@ def upper_covers_iterator(self, element):
             sage: list(H.upper_covers_iterator(7))
             []
         """
-        for x in self.neighbor_out_iterator(element):
-            yield x
+        yield from self.neighbor_out_iterator(element)
 
     def lower_covers_iterator(self, element):
         r"""
@@ -905,8 +904,7 @@ def lower_covers_iterator(self, element):
             sage: list(H.lower_covers_iterator(4))
             [1, 2]
         """
-        for x in self.neighbor_in_iterator(element):
-            yield x
+        yield from self.neighbor_in_iterator(element)
 
     def cardinality(self):
         r"""
diff --git a/src/sage/combinat/species/functorial_composition_species.py b/src/sage/combinat/species/functorial_composition_species.py
@@ -71,8 +71,7 @@ def _structures(self, structure_class, s):
              {{1, 2}*{3}, {1, 3}*{2}, {2, 3}*{1}}]
         """
         gs = self._G.structures(s).list()
-        for f in self._F.structures(gs):
-            yield f
+        yield from self._F.structures(gs)
 
     def _isotypes(self, structure_class, s):
         """
diff --git a/src/sage/combinat/subset.py b/src/sage/combinat/subset.py
@@ -1130,8 +1130,7 @@ def __iter__(self):
              [1, 2, 2, 3]]
         """
         for k in range(len(self._l) + 1):
-            for s in SubMultiset_sk(self._l, k):
-                yield s
+            yield from SubMultiset_sk(self._l, k)
 
     def __call__(self, el):
         r"""
diff --git a/src/sage/combinat/tiling.py b/src/sage/combinat/tiling.py
@@ -1220,8 +1220,7 @@ def isometric_copies(self, box, orientation_preserving=True,
         all_distinct_cano = self.canonical_isometric_copies(orientation_preserving,
                                                             mod_box_isometries)
         for cano in all_distinct_cano:
-            for t in cano.translated_copies(box=box):
-                yield t
+            yield from cano.translated_copies(box=box)
 
     def isometric_copies_intersection(self, box, orientation_preserving=True):
         r"""
diff --git a/src/sage/combinat/words/finite_word.py b/src/sage/combinat/words/finite_word.py
@@ -1731,8 +1731,7 @@ def left_special_factors_iterator(self, n=None):
         """
         if n is None:
             for i in range(self.length()):
-                for w in self.left_special_factors_iterator(i):
-                    yield w
+                yield from self.left_special_factors_iterator(i)
         else:
             left_extensions = defaultdict(set)
             for w in self.factor_iterator(n+1):
@@ -1799,8 +1798,7 @@ def right_special_factors_iterator(self, n=None):
         """
         if n is None:
             for i in range(self.length()):
-                for w in self.right_special_factors_iterator(i):
-                    yield w
+                yield from self.right_special_factors_iterator(i)
         else:
             right_extensions = defaultdict(set)
             for w in self.factor_iterator(n+1):
@@ -1890,8 +1888,7 @@ def bispecial_factors_iterator(self, n=None):
         """
         if n is None:
             for i in range(self.length()):
-                for w in self.bispecial_factors_iterator(i):
-                    yield w
+                yield from self.bispecial_factors_iterator(i)
         else:
             left_extensions = defaultdict(set)
             right_extensions = defaultdict(set)
diff --git a/src/sage/combinat/yang_baxter_graph.py b/src/sage/combinat/yang_baxter_graph.py
@@ -665,8 +665,7 @@ def __iter__(self):
             sage: list(Y.__iter__())
             [(1, 0, 2, 1, 0), (1, 2, 0, 1, 0), (1, 2, 1, 0, 0), (2, 1, 0, 1, 0), (2, 1, 1, 0, 0)]
         """
-        for v in self._vertex_ordering:
-            yield v
+        yield from self._vertex_ordering
 
     def _swap_operator(self, operator, u):
         r"""
diff --git a/src/sage/databases/oeis.py b/src/sage/databases/oeis.py
@@ -1481,9 +1481,8 @@ def __iter__(self):
             sage: s = oeis._imaginary_sequence(ident='A999991', keywords='sign,full')
             sage: for i in s: pass
         """
-        for x in self.first_terms():
-            yield x
-        if not self.is_full() is True:
+        yield from self.first_terms()
+        if self.is_full() is not True:
             raise LookupError("future values not provided by OEIS")
 
     def references(self):
diff --git a/src/sage/games/sudoku.py b/src/sage/games/sudoku.py
@@ -719,8 +719,7 @@ def backtrack(self):
         """
         from .sudoku_backtrack import backtrack_all
         solutions = backtrack_all(self.n, self.puzzle)
-        for soln in solutions:
-            yield soln
+        yield from solutions
 
     def dlx(self, count_only=False):
         r"""
diff --git a/src/sage/graphs/bipartite_graph.py b/src/sage/graphs/bipartite_graph.py
@@ -1703,8 +1703,7 @@ def rec(G):
 
         # For each unlabeled matching, we yield all its possible labelings
         for m in rec(G):
-            for pm in itertools.product(*[edges[frozenset(e)] for e in m]):
-                yield pm
+            yield from itertools.product(*[edges[frozenset(e)] for e in m])
 
     def load_afile(self, fname):
         r"""
diff --git a/src/sage/graphs/digraph_generators.py b/src/sage/graphs/digraph_generators.py
@@ -1747,8 +1747,7 @@ def extra_property(x):
             if vertices is None:
                 vertices = 0
                 while True:
-                    for g in self(vertices, sparse=sparse, copy=copy):
-                        yield g
+                    yield from self(vertices, sparse=sparse, copy=copy)
                     vertices += 1
 
             from sage.graphs.graph_generators import canaug_traverse_edge
diff --git a/src/sage/graphs/pq_trees.py b/src/sage/graphs/pq_trees.py
@@ -365,8 +365,7 @@ def __iter__(self):
             {2, 3}
             ('P', [{2, 4}, {8, 2}, {9, 2}])
         """
-        for i in self._children:
-            yield i
+        yield from self._children
 
     def number_of_children(self):
         r"""
@@ -795,13 +794,11 @@ def orderings(self):
             ({2, 4}, {0, 8}, {1, 2}, {0, 5})
             ({2, 4}, {0, 8}, {0, 5}, {1, 2})
             ...
-
         """
         from itertools import permutations, product
         for p in permutations(self._children):
-            for o in product(*[x.orderings() if isinstance(x, PQ) else [x]
-                               for x in p]):
-                yield o
+            yield from product(*[x.orderings() if isinstance(x, PQ) else [x]
+                                 for x in p])
 
 
 class Q(PQ):
@@ -1124,8 +1121,7 @@ def orderings(self):
         """
         if len(self._children) == 1:
             c = self._children[0]
-            for o in (c.orderings() if isinstance(c, PQ) else [c]):
-                yield o
+            yield from (c.orderings() if isinstance(c, PQ) else [c])
         else:
             from itertools import product
             for o in product(*[x.orderings() if isinstance(x, PQ) else [x]
diff --git a/src/sage/groups/abelian_gps/dual_abelian_group.py b/src/sage/groups/abelian_gps/dual_abelian_group.py
@@ -405,5 +405,4 @@ def __iter__(self):
             sage: len([X for X in Gd if abs(X(x)-1)>0.01 and abs(X(y)-1)>0.01 and abs(X(z)-1)>0.01])
             880
         """
-        for g in self.list():
-            yield g
+        yield from self.list()
diff --git a/src/sage/groups/libgap_mixin.py b/src/sage/groups/libgap_mixin.py
@@ -826,8 +826,7 @@ def __iter__(self):
             60
         """
         if self.list.cache is not None:
-            for g in self.list():
-                yield g
+            yield from self.list()
             return
         iterator = self.gap().Iterator()
         while not iterator.IsDoneIterator().sage():
diff --git a/src/sage/modular/multiple_zeta.py b/src/sage/modular/multiple_zeta.py
@@ -575,8 +575,7 @@ def extend_multiplicative_basis(B, n) -> Iterator:
         [((7,),), ((5,), (2,)), ((3,), (2,), (2,))]
     """
     for pi in Partitions(n, min_part=2):
-        for liste in cartesian_product([B[i] for i in pi]):
-            yield liste
+        yield from cartesian_product([B[i] for i in pi])
 
 
 # several classes for the algebra of MZV
diff --git a/src/sage/parallel/map_reduce.py b/src/sage/parallel/map_reduce.py
@@ -2010,8 +2010,7 @@ def __iter__(self):
             newres = self._results.get()
             if newres is not None:
                 logger.debug("Got some results")
-                for r in newres:
-                    yield r
+                yield from newres
             else:
                 active_proc -= 1
                 if active_proc == 0:
diff --git a/src/sage/parallel/multiprocessing_sage.py b/src/sage/parallel/multiprocessing_sage.py
@@ -74,7 +74,6 @@ def parallel_iter(processes, f, inputs):
 
     result = p.imap_unordered(call_pickled_function,
                               [(fp, t) for t in inputs])
-    for res in result:
-        yield res
+    yield from result
     p.close()
     p.join()
diff --git a/src/sage/rings/asymptotic/growth_group_cartesian.py b/src/sage/rings/asymptotic/growth_group_cartesian.py
@@ -775,8 +775,7 @@ def pushout_univariate_factors(self, other, var, Sfactors, Ofactors):
             def subfactors(F):
                 for f in F:
                     if isinstance(f, GenericProduct):
-                        for g in subfactors(f.cartesian_factors()):
-                            yield g
+                        yield from subfactors(f.cartesian_factors())
                     else:
                         yield f
 
diff --git a/src/sage/rings/polynomial/groebner_fan.py b/src/sage/rings/polynomial/groebner_fan.py
@@ -1157,8 +1157,7 @@ def __iter__(self):
             sage: next(a)
             [y^9 - 3*y^6 + 3*y^3 - y - 1, -y^3 + x + 1]
         """
-        for x in self.reduced_groebner_bases():
-            yield x
+        yield from self.reduced_groebner_bases()
 
     def __getitem__(self, i):
         """
diff --git a/src/sage/rings/polynomial/pbori/blocks.py b/src/sage/rings/polynomial/pbori/blocks.py
@@ -366,8 +366,7 @@ def canonicalize(blocks):
             if isinstance(elt, str):
                 yield elt
             else:
-                for subelt in elt:
-                    yield subelt
+                yield from elt
 
     blocks = list(blocks)
     n = 0
diff --git a/src/sage/rings/polynomial/polynomial_ring.py b/src/sage/rings/polynomial/polynomial_ring.py
@@ -1444,7 +1444,7 @@ def random_element(self, degree=(-1,2), *args, **kwds):
 
         return p
 
-    def _monics_degree( self, of_degree ):
+    def _monics_degree(self, of_degree):
         """
         Refer to monics() for full documentation.
         """
@@ -1455,15 +1455,14 @@ def _monics_degree( self, of_degree ):
             coeffs.reverse()
             yield self(coeffs)
 
-    def _monics_max( self, max_degree ):
+    def _monics_max(self, max_degree):
         """
         Refer to monics() for full documentation.
         """
         for degree in range(max_degree + 1):
-            for m in self._monics_degree( degree ):
-                yield m
+            yield from self._monics_degree(degree)
 
-    def _polys_degree( self, of_degree ):
+    def _polys_degree(self, of_degree):
         """
         Refer to polynomials() for full documentation.
         """
diff --git a/src/sage/rings/rational_field.py b/src/sage/rings/rational_field.py
diff --git a/src/sage/rings/valuation/value_group.py b/src/sage/rings/valuation/value_group.py
diff --git a/src/sage/schemes/elliptic_curves/ell_finite_field.py b/src/sage/schemes/elliptic_curves/ell_finite_field.py
diff --git a/src/sage/schemes/toric/points.py b/src/sage/schemes/toric/points.py
diff --git a/src/sage/sets/recursively_enumerated_set.pyx b/src/sage/sets/recursively_enumerated_set.pyx
diff --git a/src/sage/symbolic/expression.pyx b/src/sage/symbolic/expression.pyx
diff --git a/src/sage/tensor/modules/comp.py b/src/sage/tensor/modules/comp.py
diff --git a/src/sage/tests/arxiv_0812_2725.py b/src/sage/tests/arxiv_0812_2725.py
diff --git a/src/sage/typeset/character_art.py b/src/sage/typeset/character_art.py
