sagemathgh-41144: some type annotations in algebras,coding,graphs
    
mostly about adding type annotations like
`def __contains__(self, x) -> bool:`
and
`def __init__(self) -> None:`
and a few similar things

### 📝 Checklist

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
    
URL: sagemath#41144
Reported by: Frédéric Chapoton
Reviewer(s):

Author: Release Manager

src/sage/algebras/clifford_algebra.py

@@ -51,7 +51,7 @@ class CliffordAlgebraIndices(UniqueRepresentation, Parent):
     A facade parent for the indices of Clifford algebra.
     Users should not create instances of this class directly.
     """
-    def __init__(self, Qdim, degree=None):
+    def __init__(self, Qdim, degree=None) -> None:
         r"""
         Initialize ``self``.
 
@@ -271,7 +271,7 @@ def __iter__(self):
                 yield FrozenBitset(C)
             k += 1
 
-    def __contains__(self, elt):
+    def __contains__(self, elt) -> bool:
         r"""
         Check containment of ``elt`` in ``self``.
 
@@ -503,7 +503,7 @@ def __classcall_private__(cls, Q, names=None):
                 raise ValueError("the number of variables does not match the number of generators")
         return super().__classcall__(cls, Q, names)
 
-    def __init__(self, Q, names, category=None):
+    def __init__(self, Q, names, category=None) -> None:
         r"""
         Initialize ``self``.
 
@@ -1463,7 +1463,7 @@ def __classcall_private__(cls, R, names=None, n=None):
                 raise ValueError("the number of variables does not match the number of generators")
         return super().__classcall__(cls, R, names)
 
-    def __init__(self, R, names):
+    def __init__(self, R, names) -> None:
         """
         Initialize ``self``.
 
@@ -2124,7 +2124,7 @@ def __classcall__(cls, E, s_coeff):
         from sage.sets.family import Family
         return super().__classcall__(cls, E, Family(d))
 
-    def __init__(self, E, s_coeff):
+    def __init__(self, E, s_coeff) -> None:
         """
         Initialize ``self``.
 
@@ -2538,7 +2538,7 @@ class ExteriorAlgebraCoboundary(ExteriorAlgebraDifferential):
 
     - :wikipedia:`Exterior_algebra#Differential_geometry`
     """
-    def __init__(self, E, s_coeff):
+    def __init__(self, E, s_coeff) -> None:
         """
         Initialize ``self``.
 
@@ -2733,7 +2733,7 @@ class ExteriorAlgebraIdeal(Ideal_nc):
         sage: xbar * ybar
         0
     """
-    def __init__(self, ring, gens, coerce=True, side='twosided'):
+    def __init__(self, ring, gens, coerce=True, side='twosided') -> None:
         """
         Initialize ``self``.
 
@@ -2815,7 +2815,7 @@ def _contains_(self, f):
         """
         return not self.reduce(f)
 
-    def __richcmp__(self, other, op):
+    def __richcmp__(self, other, op) -> bool:
         """
         Compare ``self`` and ``other``.
 

src/sage/algebras/finite_dimensional_algebras/finite_dimensional_algebra_ideal.py

@@ -47,7 +47,7 @@ class FiniteDimensionalAlgebraIdeal(Ideal_generic):
         sage: A.ideal(A([0,1]))
         Ideal (e1) of Finite-dimensional algebra of degree 2 over Finite Field of size 3
     """
-    def __init__(self, A, gens=None, given_by_matrix=False):
+    def __init__(self, A, gens=None, given_by_matrix=False) -> bool:
         """
         EXAMPLES::
 
@@ -138,7 +138,7 @@ def _richcmp_(self, other, op):
         elif op == op_GE or op == op_GT:
             return other.vector_space().is_subspace(self.vector_space())
 
-    def __contains__(self, elt):
+    def __contains__(self, elt) -> bool:
         """
         EXAMPLES::
 

src/sage/algebras/letterplace/letterplace_ideal.pyx

@@ -155,7 +155,7 @@ class LetterplaceIdeal(Ideal_nc):
         sage: (z*I.0-x*y*z).normal_form(I)
         -y*x*z + z*z
     """
-    def __init__(self, ring, gens, coerce=True, side='twosided'):
+    def __init__(self, ring, gens, coerce=True, side='twosided') -> None:
         """
         INPUT:
 
@@ -334,7 +334,7 @@ class LetterplaceIdeal(Ideal_nc):
         self.__GB.__uptodeg = degbound
         return self.__GB
 
-    def __contains__(self, x):
+    def __contains__(self, x) -> bool:
         """
         The containment test is based on a normal form computation.
 

src/sage/algebras/lie_algebras/affine_lie_algebra.py

@@ -106,7 +106,7 @@ def __classcall_private__(cls, arg0, cartan_type=None, kac_moody=True):
             return UntwistedAffineLieAlgebra(g, kac_moody=kac_moody)
         return TwistedAffineLieAlgebra(arg0, cartan_type, kac_moody=kac_moody)
 
-    def __init__(self, g, cartan_type, names, kac_moody):
+    def __init__(self, g, cartan_type, names, kac_moody) -> None:
         """
         Initialize ``self``.
 
@@ -578,7 +578,7 @@ class UntwistedAffineLieAlgebra(AffineLieAlgebra):
         sage: D.d()
         0
     """
-    def __init__(self, g, kac_moody):
+    def __init__(self, g, kac_moody) -> None:
         """
         Initialize ``self``.
 
@@ -671,7 +671,7 @@ class TwistedAffineLieAlgebra(AffineLieAlgebra):
     weights in this representation with the roots of type `B_n` and
     the double all of its short roots.
     """
-    def __init__(self, R, cartan_type, kac_moody):
+    def __init__(self, R, cartan_type, kac_moody) -> None:
         """
         Initialize ``self``.
 
@@ -1107,7 +1107,7 @@ def __classcall_private__(cls, cartan_type):
             raise ValueError("the Cartan type must be a twisted affine type")
         return super().__classcall__(cls, cartan_type)
 
-    def __init__(self, cartan_type):
+    def __init__(self, cartan_type) -> None:
         """
         Initialize ``self``.
 
@@ -1141,7 +1141,7 @@ def __init__(self, cartan_type):
         from sage.categories.infinite_enumerated_sets import InfiniteEnumeratedSets
         super().__init__(facade=facade, category=InfiniteEnumeratedSets())
 
-    def __contains__(self, x):
+    def __contains__(self, x) -> bool:
         """
         Return if ``x`` is contained in ``self``.
 

src/sage/algebras/lie_algebras/bgg_dual_module.py

@@ -100,7 +100,7 @@ class BGGDualModule(CombinatorialFreeModule):
 
     - [Humphreys08]_
     """
-    def __init__(self, module):
+    def __init__(self, module) -> None:
         r"""
         Initialize ``self``.
 
@@ -458,7 +458,7 @@ def __classcall__(cls, simple, prefix='f', **kwds):
         """
         return super(IndexedMonoid, cls).__classcall__(cls, simple, prefix=prefix, **kwds)
 
-    def __init__(self, simple, prefix, category=None, **kwds):
+    def __init__(self, simple, prefix, category=None, **kwds) -> None:
         r"""
         Initialize ``self``.
 
@@ -591,7 +591,7 @@ def weight_space_basis(self, mu):
             self._construct_next_level()
         return self._weight_space_bases.get(mu, [])
 
-    def __contains__(self, m):
+    def __contains__(self, m) -> bool:
         r"""
         Check if ``m`` is contained in ``self``.
 
@@ -815,7 +815,7 @@ def __classcall_private__(cls, g, weight, *args, **kwds):
             return FiniteDimensionalSimpleModule(g, weight, *args, **kwds)
         return super().__classcall__(cls, g, weight, *args, **kwds)
 
-    def __init__(self, g, weight, prefix='f', basis_key=None, **kwds):
+    def __init__(self, g, weight, prefix='f', basis_key=None, **kwds) -> None:
         r"""
         Initialize ``self``.
 

src/sage/algebras/lie_algebras/subalgebra.py

@@ -260,7 +260,8 @@ def __classcall_private__(cls, ambient, gens, ideal_of=None,
         return super().__classcall__(cls, ambient, gens, ideal_of,
                                      order, category)
 
-    def __init__(self, ambient, gens, ideal_of, order=None, category=None):
+    def __init__(self, ambient, gens, ideal_of,
+                 order=None, category=None) -> None:
         r"""
         Initialize ``self``.
 
@@ -302,7 +303,7 @@ def __init__(self, ambient, gens, ideal_of, order=None, category=None):
         f = SetMorphism(H, self.lift)
         ambient.register_coercion(f)
 
-    def __contains__(self, x):
+    def __contains__(self, x) -> bool:
         r"""
         Return ``True`` if ``x`` is an element of ``self``.
 
@@ -338,7 +339,8 @@ def __getitem__(self, x):
         If `x` is a pair `(a, b)`, return the Lie bracket `[a, b]`.
         Otherwise try to return the `x`-th element of ``self``.
 
-        This replicates the convenience syntax for Lie brackets of Lie algebras.
+        This replicates the convenience syntax for Lie brackets
+        of Lie algebras.
 
         EXAMPLES::
 

src/sage/algebras/quatalg/quaternion_algebra.py

@@ -823,7 +823,7 @@ class QuaternionAlgebra_ab(QuaternionAlgebra_abstract):
         sage: QuaternionAlgebra(QQ, -7, -21)  # indirect doctest
         Quaternion Algebra (-7, -21) with base ring Rational Field
     """
-    def __init__(self, base_ring, a, b, names='i,j,k'):
+    def __init__(self, base_ring, a, b, names='i,j,k') -> None:
         """
         Create the quaternion algebra with `i^2 = a`, `j^2 = b`, and
         `ij = -ji = k`.
@@ -1234,7 +1234,7 @@ def invariants(self):
         """
         return self._a, self._b
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         """
         Compare ``self`` and ``other``.
 
@@ -1250,7 +1250,7 @@ def __eq__(self, other):
         return (self.base_ring() == other.base_ring() and
                 (self._a, self._b) == (other._a, other._b))
 
-    def __ne__(self, other):
+    def __ne__(self, other) -> bool:
         """
         Compare ``self`` and ``other``.
 
@@ -1263,7 +1263,7 @@ def __ne__(self, other):
         """
         return not self.__eq__(other)
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         """
         Compute the hash of ``self``.
 
@@ -1985,7 +1985,7 @@ class QuaternionOrder(Parent):
         sage: type(QuaternionAlgebra(-1,-7).maximal_order())
         <class 'sage.algebras.quatalg.quaternion_algebra.QuaternionOrder_with_category'>
     """
-    def __init__(self, A, basis, check=True):
+    def __init__(self, A, basis, check=True) -> None:
         """
         INPUT:
 
@@ -2186,7 +2186,7 @@ def gen(self, n):
         """
         return self.__basis[n]
 
-    def __richcmp__(self, other, op):
+    def __richcmp__(self, other, op) -> bool:
         """
         Compare this quaternion order to ``other``.
 
@@ -2239,7 +2239,7 @@ def __richcmp__(self, other, op):
             return op == op_NE
         return richcmp(self.unit_ideal(), other.unit_ideal(), op)
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         """
         Compute the hash of ``self``.
 
@@ -3013,7 +3013,8 @@ class QuaternionFractionalIdeal_rational(QuaternionFractionalIdeal):
     - ``check`` -- boolean (default: ``True``); if ``False``, do no type
       checking.
     """
-    def __init__(self, Q, basis, left_order=None, right_order=None, check=True):
+    def __init__(self, Q, basis, left_order=None,
+                 right_order=None, check=True) -> None:
         """
         EXAMPLES::
 
@@ -3267,7 +3268,7 @@ def right_order(self):
             self.__right_order = self._compute_order(side='right')
         return self.__right_order
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         """
         Return string representation of this quaternion fractional ideal.
 
@@ -3361,7 +3362,7 @@ def _richcmp_(self, right, op):
         """
         return self.free_module().__richcmp__(right.free_module(), op)
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         """
         Return the hash of ``self``.
 
@@ -4165,7 +4166,7 @@ def is_principal(self, certificate=False):
         # find an element of minimal norm in self; see [Piz1980]_, Corollary 1.20.
         return True, self.minimal_element()
 
-    def __contains__(self, x):
+    def __contains__(self, x) -> bool:
         """
         Return whether ``x`` is in ``self``.
 

src/sage/algebras/steenrod/steenrod_algebra.py

@@ -2129,7 +2129,7 @@ def _element_constructor_(self, x):
                 return a.change_basis(self.basis_name())
         raise ValueError("element does not lie in this Steenrod algebra")
 
-    def __contains__(self, x):
+    def __contains__(self, x) -> bool:
         r"""
         Return ``True`` if ``self`` contains `x`.
 

src/sage/coding/abstract_code.py

@@ -203,7 +203,7 @@ class AbstractCode(Parent):
     """
 
     def __init__(self, length, default_encoder_name=None,
-                 default_decoder_name=None, metric='Hamming'):
+                 default_decoder_name=None, metric='Hamming') -> None:
         r"""
         Initialize mandatory parameters that any code shares.
 
@@ -353,7 +353,7 @@ def __iter__(self):
         """
         raise RuntimeError("Please override __iter__ in the implementation of {}".format(self.parent()))
 
-    def __contains__(self, c):
+    def __contains__(self, c) -> bool:
         r"""
         Return an error message requiring to override ``__contains__`` in ``self``.