gh-37772: add links to standard errors in toric folder

adding links to standard python errors in the doc inside the
`schemes/toric` folder

plus a few pep8 cleanups

### 📝 Checklist

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.

URL: #37772
Reported by: Frédéric Chapoton
Reviewer(s): Matthias Köppe

build/pkgs/configure/checksums.ini

@@ -1,4 +1,4 @@
 tarball=configure-VERSION.tar.gz
-sha1=a8f26f365284ca719e583e703c5b8eeb656b35ab
-md5=612ba76c797d5fc92e272a59b1b7b2e6
-cksum=2444442853
+sha1=e00d37668d4c323478c575234b3e8513923c09f6
+md5=19845ef8465f120fb16811052483c0b1
+cksum=3911910914

build/pkgs/configure/package-version.txt

@@ -1 +1 @@
-6d187b153b5b5c3e29fe07d9efe925e34bf5baa5
+86cd345f191738d8b40af5f0772173ff5ae49515

src/sage/schemes/toric/chow_group.py

@@ -231,12 +231,14 @@ def _repr_(self) -> str:
 
     def degree(self) -> int:
         r"""
-        The degree of the Chow cycle.
+        Return the degree of the Chow cycle.
 
         OUTPUT:
 
         Integer. The complex dimension of the subvariety representing
-        the Chow cycle. Raises a ``ValueError`` if the Chow cycle is a
+        the Chow cycle.
+
+        This raises a :class:`ValueError` if the Chow cycle is a
         sum of mixed degree cycles.
 
         EXAMPLES::
@@ -355,7 +357,7 @@ def intersection_with_divisor(self, divisor):
         OUTPUT:
 
         A new :class:`ChowCycle`. If the divisor is not Cartier then
-        this method potentially raises a ``ValueError``, indicating
+        this method potentially raises a :class:`ValueError`, indicating
         that the divisor cannot be made transversal to the Chow cycle.
 
         EXAMPLES::
@@ -472,7 +474,7 @@ def cohomology_class(self):
         If the toric variety is not simplicial, that is, has worse
         than orbifold singularities, there is no way to associate a
         cohomology class of the correct degree. In this case,
-        :meth:`cohomology_class` raises a ``ValueError``.
+        :meth:`cohomology_class` raises a :class:`ValueError`.
 
         EXAMPLES::
 

src/sage/schemes/toric/divisor.py

@@ -568,7 +568,7 @@ def m(self, cone):
           returned.
 
         - If there is no such vector (i.e. ``self`` is not even a
-          `\QQ`-Cartier divisor), a ``ValueError`` is raised.
+          `\QQ`-Cartier divisor), a :class:`ValueError` is raised.
 
         EXAMPLES::
 
@@ -774,7 +774,7 @@ def move_away_from(self, cone):
         .. NOTE::
 
             A divisor that is Weil but not Cartier might be impossible
-            to move away. In this case, a ``ValueError`` is raised.
+            to move away. In this case, a :class:`ValueError` is raised.
 
         EXAMPLES::
 

src/sage/schemes/toric/divisor_class.pyx

@@ -205,7 +205,7 @@ cdef class ToricRationalDivisorClass(Vector_rational_dense):
 
     cpdef _dot_product_(self, Vector right):
         r"""
-        Raise a ``TypeError`` exception.
+        Raise a :class:`TypeError` exception.
 
         Dot product is not defined on toric rational divisor classes.
 
@@ -215,7 +215,7 @@ cdef class ToricRationalDivisorClass(Vector_rational_dense):
 
         OUTPUT:
 
-        - ``TypeError`` exception is raised.
+        A :class:`TypeError` exception is raised.
 
         TESTS::
 

src/sage/schemes/toric/ideal.py

@@ -162,7 +162,7 @@ class ToricIdeal(MPolynomialIdeal):
 
       You may specify the ambient polynomial ring via the
       ``polynomial_ring`` parameter or via the ``names`` and
-      ``base_ring`` parameter. A ``ValueError`` is raised if you
+      ``base_ring`` parameter. A :class:`ValueError` is raised if you
       specify both.
 
     - ``algorithm`` -- string (optional). The algorithm to use. For

src/sage/schemes/toric/morphism.py

@@ -522,7 +522,8 @@ def as_fan_morphism(self):
 
         OUTPUT: A :class:`SchemeMorphism_polynomial_toric_variety`.
 
-        Raises a ``TypeError`` if the morphism cannot be written in such a way.
+        This raises a :class:`TypeError` if the morphism cannot be written
+        in such a way.
 
         EXAMPLES::
 
@@ -681,9 +682,10 @@ def as_polynomial_map(self):
 
         OUTPUT:
 
-        A :class:`SchemeMorphism_polynomial_toric_variety`. Raises a
-        ``TypeError`` if the morphism cannot be written in terms of
-        homogeneous polynomials.
+        A :class:`SchemeMorphism_polynomial_toric_variety`.
+
+        This raises a :class:`TypeError` if the morphism cannot be
+        written in terms of homogeneous polynomials.
 
         The defining polynomials are not necessarily unique. There are
         choices if multiple ambient space ray generators project to
@@ -717,7 +719,7 @@ def as_polynomial_map(self):
         orbit = self.domain()
         codomain_fan = self.codomain().fan()
         R = orbit.coordinate_ring()
-        polys = [ R.one() ] * codomain_fan.nrays()
+        polys = [R.one()] * codomain_fan.nrays()
         for i in self._defining_cone.ambient_ray_indices():
             polys[i] = R.zero()
         ray_index_map = self._reverse_ray_map()
@@ -1071,8 +1073,8 @@ def as_polynomial_map(self):
 
         OUTPUT: A :class:`SchemeMorphism_polynomial_toric_variety`.
 
-        Raises a ``TypeError`` if the morphism cannot be written in terms of
-        homogeneous polynomials.
+        This raises a :class:`TypeError` if the morphism cannot be written
+        in terms of homogeneous polynomials.
 
         EXAMPLES::
 
@@ -1105,8 +1107,8 @@ def as_polynomial_map(self):
                                     'homogeneous polynomials')
                 polys[i] *= x**d
         if phi.domain_fan().virtual_rays():
-            raise NotImplementedError("polynomial representations for fans "
-                                    "with virtual rays are not implemented yet")
+            raise NotImplementedError("polynomial representations for fans with"
+                                      " virtual rays are not implemented yet")
         return SchemeMorphism_polynomial_toric_variety(self.parent(), polys)
 
     def is_bundle(self):
@@ -1478,7 +1480,7 @@ def fiber_component(self, domain_cone, multiplicity=False):
         embedding = SchemeMorphism_fan_fiber_component_toric_variety(self, domain_cone)
         if multiplicity:
             return embedding.domain(), \
-               self.fan_morphism().index(embedding.base_cone())
+                self.fan_morphism().index(embedding.base_cone())
         else:
             return embedding.domain()
 
@@ -1610,7 +1612,7 @@ def is_union_in_fan(self, c0, c1):
             except ValueError:
                 return False
 
-        m = matrix(ZZ, n, n, lambda i,j:is_union_in_fan(self,prim[i], prim[j]))
+        m = matrix(ZZ, n, n, lambda i, j: is_union_in_fan(self, prim[i], prim[j]))
 
         for i in range(n):
             m[i, i] = 0
@@ -1728,9 +1730,10 @@ def as_polynomial_map(self):
 
         OUTPUT:
 
-        A :class:`SchemeMorphism_polynomial_toric_variety`. Raises a
-        ``ValueError`` if the morphism cannot be written in terms of
-        homogeneous polynomials.
+        A :class:`SchemeMorphism_polynomial_toric_variety`.
+
+        This raises a :class:`ValueError` if the morphism cannot be
+        written in terms of homogeneous polynomials.
 
         EXAMPLES::
 
@@ -1831,7 +1834,7 @@ def projection(ray):
         star_rays = set()
         for cone in fm.relative_star_generators(defining_cone):
             star_rays.update(cone.rays())
-            projected_rays = [ projection(r) for r in cone.rays() ]
+            projected_rays = [projection(r) for r in cone.rays()]
             cones.append(Cone(projected_rays))
         fiber_fan = Fan(cones)