Trac #21266: py3: get rid of iterkeys

as a step towards py3, do not use iterkeys

(there remains 3 more subtle uses of iterkeys)

I have also taken the opprtunity to remove deprecated code in
src/sage/combinat/finite_state_machine.py

URL: https://trac.sagemath.org/21266
Reported by: chapoton
Ticket author(s): Frédéric Chapoton
Reviewer(s): Jori Mäntysalo

src/sage/algebras/letterplace/free_algebra_letterplace.pyx

@@ -833,7 +833,7 @@ cdef class FreeAlgebra_letterplace(Algebra):
         if not D:
             return self.zero()
         cdef int l
-        for e in D.iterkeys():
+        for e in D:
             l = len(e)
             break
         cdef dict out = {}

src/sage/categories/category_cy_helper.pyx

@@ -110,8 +110,8 @@ cpdef tuple _flatten_categories(categories, ClasscallMetaclass JoinCategory):
 
 cdef bint is_supercategory_of_done(new_cat, dict done):
     # This is a helper function. It replaces the closure
-    #   any(cat.is_subcategory(new_cat) for cat in done.iterkeys())
-    for cat in done.iterkeys():
+    # any(cat.is_subcategory(new_cat) for cat in done)
+    for cat in done:
         if cat.is_subcategory(new_cat):
             return True
     return False
@@ -193,7 +193,7 @@ cpdef tuple join_as_tuple(tuple categories, tuple axioms, tuple ignore_axioms):
                     new_axioms.add(axiom)
 
         # Mark old categories with new axioms as todo
-        for category in done.iterkeys():
+        for category in done:
             for axiom in new_axioms:
                 todo.add( (category, axiom) )
         for new_cat in new_cats:
@@ -205,7 +205,7 @@ cpdef tuple join_as_tuple(tuple categories, tuple axioms, tuple ignore_axioms):
             for axiom in axiomsS.difference(axs):
                 todo.add( (new_cat, axiom) )
 
-    return _sort_uniq(done.iterkeys())
+    return _sort_uniq(done)
 
 
 #############################################

src/sage/coding/codecan/codecan.pyx

@@ -297,7 +297,7 @@ cdef class InnerGroup:
                     factor = d.get(self.get_rep(i))
                     if factor and not factor.is_zero():
                         m.rescale_row(i, factor)
-                for i in d.iterkeys():
+                for i in d:
                     first_nz_rep = self.join_rows(first_nz_rep, i)
                 # rescale the already fixed part by column multiplications
                 for col in fixed_minimized_cols:

src/sage/combinat/finite_state_machine.py

@@ -4696,7 +4696,7 @@ def latex_options(self,
             self.format_transition_label = format_transition_label
 
         if loop_where is not None:
-            permissible = list(tikz_automata_where.iterkeys())
+            permissible = list(tikz_automata_where)
             for state in self.states():
                 if hasattr(loop_where, '__call__'):
                     where = loop_where(state.label())
@@ -4715,7 +4715,7 @@ def latex_options(self,
                                      (state.label(), permissible))
 
         if initial_where is not None:
-            permissible = list(tikz_automata_where.iterkeys())
+            permissible = list(tikz_automata_where)
             for state in self.iter_initial_states():
                 if hasattr(initial_where, '__call__'):
                     where = initial_where(state.label())
@@ -4746,7 +4746,7 @@ def latex_options(self,
             self.accepting_distance = accepting_distance
 
         if accepting_where is not None:
-            permissible = list(tikz_automata_where.iterkeys())
+            permissible = list(tikz_automata_where)
             for state in self.iter_final_states():
                 if hasattr(accepting_where, '__call__'):
                     where = accepting_where(state.label())
@@ -14945,7 +14945,6 @@ def result(self, format_output=None):
             return self._finished_
         return [r[:2] + (format_output(r[2]),) for r in self._finished_]
 
-
     def preview_word(self, track_number=None, length=1, return_word=False):
         """
         Reads a word from the input tape.
@@ -15000,140 +14999,6 @@ def preview_word(self, track_number=None, length=1, return_word=False):
             track_number, length, return_word)
 
 
-    @property
-    def current_state(self):
-        """
-        The current/reached state in the process.
-
-        .. WARNING::
-
-            This attribute is deprecated and should not be used any
-            longer (it may return a wrong result for non-deterministic
-            finite state machines).
-
-        TESTS::
-
-            sage: inverter = Transducer({'A': [('A', 0, 1), ('A', 1, 0)]},
-            ....:     initial_states=['A'], final_states=['A'])
-            sage: it = inverter.iter_process(input_tape=[0, 1, 1])
-            sage: for current in it:
-            ....:     s = it.current_state
-            ....:     print(current)
-            ....:     print('current state: {}'.format(s))
-            doctest:...: DeprecationWarning: This attribute will be
-            removed in future releases. Use result() at the end of our
-            iteration or the output of next().
-            See http://trac.sagemath.org/16538 for details.
-            process (1 branch)
-            + at state 'A'
-            +-- tape at 1, [[1]]
-            current state: 'A'
-            process (1 branch)
-            + at state 'A'
-            +-- tape at 2, [[1, 0]]
-            current state: 'A'
-            process (1 branch)
-            + at state 'A'
-            +-- tape at 3, [[1, 0, 0]]
-            current state: 'A'
-            process (0 branches)
-            current state: None
-        """
-        from sage.misc.superseded import deprecation
-        deprecation(16538, 'This attribute will be removed in future '
-                    'releases. Use result() at the end of our '
-                    'iteration or the output of next().')
-        if not self._current_:
-            return None
-        return next(next(self._current_.itervalues()).iterkeys())
-
-
-    @property
-    def output_tape(self):
-        """
-        The written output.
-
-        .. WARNING::
-
-            This attribute is deprecated and should not be used any
-            longer (it may return a wrong result for non-deterministic
-            finite state machines).
-
-        TESTS::
-
-            sage: inverter = Transducer({'A': [('A', 0, 1), ('A', 1, 0)]},
-            ....:     initial_states=['A'], final_states=['A'])
-            sage: it = inverter.iter_process(input_tape=[0, 1, 1])
-            sage: for current in it:
-            ....:     t = it.output_tape
-            ....:     print(current)
-            ....:     print('output: {}'.format(t))
-            doctest:...: DeprecationWarning: This attribute will be removed
-            in future releases. Use result() at the end of our iteration
-            or the output of next().
-            See http://trac.sagemath.org/16538 for details.
-            process (1 branch)
-            + at state 'A'
-            +-- tape at 1, [[1]]
-            output: [1]
-            process (1 branch)
-            + at state 'A'
-            +-- tape at 2, [[1, 0]]
-            output: [1, 0]
-            process (1 branch)
-            + at state 'A'
-            +-- tape at 3, [[1, 0, 0]]
-            output: [1, 0, 0]
-            process (0 branches)
-            output: None
-        """
-        from sage.misc.superseded import deprecation
-        deprecation(16538, 'This attribute will be removed in future '
-                    'releases. Use result() at the end of our iteration '
-                    'or the output of next().')
-        if not self._current_:
-            return None
-        return next(next(self._current_.itervalues()).itervalues()).outputs[0]
-
-
-    @property
-    def accept_input(self):
-        """
-        Is ``True`` if the reached state is accepted. This is only available
-        at the end of the iteration process.
-
-        .. WARNING::
-
-            This attribute is deprecated and should not be used any
-            longer (it may return a wrong result for non-deterministic
-            finite state machines).
-
-        TESTS::
-
-            sage: inverter = Transducer({'A': [('A', 0, 1), ('A', 1, 0)]},
-            ....:     initial_states=['A'], final_states=['A'])
-            sage: it = inverter.iter_process(input_tape=[0, 1, 1])
-            sage: for _ in it:
-            ....:     pass
-            sage: it.result()
-            [Branch(accept=True, state='A', output=[1, 0, 0])]
-            sage: it.accept_input
-            doctest:...: DeprecationWarning: This attribute will be removed
-            in future releases. Use result() at the end of our iteration
-            or the output of next().
-            See http://trac.sagemath.org/16538 for details.
-            True
-        """
-        from sage.misc.superseded import deprecation
-        deprecation(16538, 'This attribute will be removed in future '
-                    'releases. Use result() at the end of our iteration '
-                    'or the output of next().')
-        try:
-            return self._finished_[0].accept
-        except KeyError:
-            raise AttributeError
-
-
 #*****************************************************************************
 
 

src/sage/combinat/finite_state_machine_generators.py

@@ -1977,7 +1977,7 @@ def f(n):
              if carry >= 0},
             multiedges=False)
 
-        initial_values_set = set(initial_values.iterkeys())
+        initial_values_set = set(initial_values)
 
         missing_initial_values = required_initial_values.difference(
             initial_values_set)

src/sage/combinat/integer_lists/invlex.pyx

@@ -29,6 +29,8 @@ limitations and lack of robustness w.r.t. input.
 #*****************************************************************************
 from __future__ import print_function
 
+from builtins import object
+
 from sage.misc.classcall_metaclass import ClasscallMetaclass, typecall
 from sage.misc.cachefunc import cached_method
 from sage.combinat.integer_lists.base cimport IntegerListsBackend
@@ -1285,7 +1287,7 @@ class IntegerListsLexIter(object):
             self._current_sum -= self._current_list[-1]
             self._current_list.pop()
 
-    def next(self):
+    def __next__(self):
         r"""
         Return the next element in the iteration.
 

src/sage/dynamics/interval_exchanges/template.py

@@ -3313,7 +3313,7 @@ def __iter__(self):
             H(0, 0)
             H(0, 0)
         """
-        for data in self._succ.iterkeys():
+        for data in self._succ:
             yield self._vertex_to_permutation(data)
 
     def __contains__(self, element):
@@ -3335,7 +3335,7 @@ def __contains__(self, element):
             sage: q in s
             True
         """
-        for p in self._succ.iterkeys():
+        for p in self._succ:
             if self._vertex_to_permutation(p) == element:
                 return True
 

src/sage/graphs/base/c_graph.pyx

@@ -1846,7 +1846,7 @@ cdef class CGraphBackend(GenericGraphBackend):
         """
         cdef int i
         if verts is None:
-            S = set(self.vertex_ints.iterkeys())
+            S = set(self.vertex_ints)
             for i in range((<CGraph>self._cg).active_vertices.size):
                 if (i not in self.vertex_labels and
                     bitset_in((<CGraph>self._cg).active_vertices, i)):

src/sage/graphs/generic_graph.py

@@ -9776,7 +9776,7 @@ def vertex_iterator(self, vertices=None):
             100000 loops, best of 3: 8.85 [micro]s per loop
             sage: timeit V = list(P.vertex_iterator())      # not tested
             100000 loops, best of 3: 5.74 [micro]s per loop
-            sage: timeit V = list(P._nxg.adj.iterkeys())    # not tested
+            sage: timeit V = list(P._nxg.adj)    # not tested
             100000 loops, best of 3: 3.45 [micro]s per loop
 
         In other words, if you want a fast vertex iterator, call the
@@ -9855,7 +9855,7 @@ def vertices(self, key=None):
             100000 loops, best of 3: 8.85 [micro]s per loop
             sage: timeit V = list(P.vertex_iterator())        # not tested
             100000 loops, best of 3: 5.74 [micro]s per loop
-            sage: timeit V = list(P._nxg.adj.iterkeys())      # not tested
+            sage: timeit V = list(P._nxg.adj)      # not tested
             100000 loops, best of 3: 3.45 [micro]s per loop
 
         We illustrate various ways to use a ``key`` to sort the list::
@@ -17341,14 +17341,14 @@ def _color_by_label(self, format='hex', as_function=False, default_color = "blac
         The default output is a dictionary assigning edges to colors::
 
             sage: G._color_by_label()
-            {'#0000ff': [((1,3,2,4), (1,4)(2,3), 3), ..., ((1,3), (1,4,3), 3)],
-             '#00ff00': [((1,3,2,4), (1,2,4), 2), ..., ((1,3), (1,2,3), 2)],
-             '#ff0000': [((1,3,2,4), (1,3)(2,4), 1), ..., ((1,3), (1,3,2), 1)]}
+            {'#0000ff': [((1,3,2,4), (1,4)(2,3), 3), ...],
+             '#00ff00': [((1,3,2,4), (1,2,4), 2), ...],
+             '#ff0000': [((1,3,2,4), (1,3)(2,4), 1), ...]}
 
             sage: G._color_by_label({1: "blue", 2: "red", 3: "green"})
-            {'blue': [((1,3,2,4), (1,3)(2,4), 1), ..., ((1,3), (1,3,2), 1)],
-             'green': [((1,3,2,4), (1,4)(2,3), 3), ..., ((1,3), (1,4,3), 3)],
-             'red': [((1,3,2,4), (1,2,4), 2), ..., ((1,3), (1,2,3), 2)]}
+            {'blue': [((1,3,2,4), (1,3)(2,4), 1), ...],
+             'green': [((1,3,2,4), (1,4)(2,3), 3), ...],
+             'red': [((1,3,2,4), (1,2,4), 2), ...]}
 
         TESTS:
 
@@ -19831,7 +19831,7 @@ def relabel(self, perm=None, inplace=True, return_map=False, check_input = True,
             if len(set(perm.values())) < len(perm):
                 raise NotImplementedError("Non injective relabeling")
 
-            for v in perm.iterkeys():
+            for v in perm:
                 if v in self:
                     try:
                         hash(perm[v])

src/sage/graphs/graph.py

@@ -5499,7 +5499,7 @@ def cliques_number_of(self, vertices=None, cliques=None):
             {0: 1, 1: 1, 2: 1, 3: 1, 4: 2}
             sage: F = graphs.Grid2dGraph(2,3)
             sage: X = F.cliques_number_of()
-            sage: for v in sorted(X.iterkeys()):
+            sage: for v in sorted(X):
             ....:     print("{} {}".format(v, X[v]))
             (0, 0) 2
             (0, 1) 3
@@ -5992,7 +5992,7 @@ def cliques_vertex_clique_number(self, algorithm="cliquer", vertices=None,
             {0: 2, 1: 4, 2: 4, 3: 4, 4: 4}
             sage: F = graphs.Grid2dGraph(2,3)
             sage: X = F.cliques_vertex_clique_number(algorithm="networkx")
-            sage: for v in sorted(X.iterkeys()):
+            sage: for v in sorted(X):
             ....:     print("{} {}".format(v, X[v]))
             (0, 0) 2
             (0, 1) 2
@@ -6056,7 +6056,7 @@ def cliques_containing_vertex(self, vertices=None, cliques=None):
             {0: [[0, 4]], 1: [[1, 2, 3, 4]], 2: [[1, 2, 3, 4]], 3: [[1, 2, 3, 4]], 4: [[0, 4], [1, 2, 3, 4]]}
             sage: F = graphs.Grid2dGraph(2,3)
             sage: X = F.cliques_containing_vertex()
-            sage: for v in sorted(X.iterkeys()):
+            sage: for v in sorted(X):
             ....:     print("{} {}".format(v, X[v]))
             (0, 0) [[(0, 1), (0, 0)], [(1, 0), (0, 0)]]
             (0, 1) [[(0, 1), (0, 0)], [(0, 1), (0, 2)], [(0, 1), (1, 1)]]

src/sage/groups/perm_gps/partn_ref/refinement_graphs.pyx

@@ -91,7 +91,7 @@ def isomorphic(G1, G2, partn, ordering2, dig, use_indicator_function, sparse=Fal
                 G_in = copy(G_in)
                 to = G_in.relabel(return_map=True)
                 frm = {}
-                for v in to.iterkeys():
+                for v in to:
                     frm[to[v]] = v
                 if first:
                     partition = [[to[v] for v in cell] for cell in partn]
@@ -382,7 +382,7 @@ def search_tree(G_in, partition, lab=True, dig=False, dict_rep=False, certificat
             G_in = copy(G_in)
             to = G_in.relabel(return_map=True)
             frm = {}
-            for v in to.iterkeys():
+            for v in to:
                 frm[to[v]] = v
             partition = [[to[v] for v in cell] for cell in partition]
         else:
@@ -459,7 +459,7 @@ def search_tree(G_in, partition, lab=True, dig=False, dict_rep=False, certificat
     return_tuple = [list_of_gens]
     if dict_rep:
         ddd = {}
-        for v in frm.iterkeys():
+        for v in frm:
             ddd[frm[v]] = v if v != 0 else n
         return_tuple.append(ddd)
     if lab:

src/sage/libs/gap/util.pyx

@@ -134,7 +134,7 @@ cdef void gasman_callback():
     Callback before each GAP garbage collection
     """
     global owned_objects_refcount
-    for obj in owned_objects_refcount.iterkeys():
+    for obj in owned_objects_refcount:
         libGAP_MARK_BAG((<ObjWrapper>obj).value)
 
 

src/sage/matroids/circuit_closures_matroid.pyx

@@ -159,7 +159,7 @@ cdef class CircuitClosuresMatroid(Matroid):
         else:
             self._groundset = frozenset(groundset)
             self._circuit_closures = {}
-            for k in circuit_closures.iterkeys():
+            for k in circuit_closures:
                 self._circuit_closures[k] = frozenset([frozenset(X) for X in circuit_closures[k]])
         self._matroid_rank = self.rank(self._groundset)