40081: add doctest and fixup

Author: soehms

src/sage/interfaces/khoca.py

@@ -91,6 +91,23 @@ def khoca_interface(ring, **kwds):
     Return an instance of ``InteractiveCalculator` of the ``Khoca``.
     This is a calculator for Khovanov homology written by Lukas
     Lewark. For more information see :class:`~sage.features.khoca.Khoca`.
+
+    EXAMPLES::
+
+        sage: # optional khoca
+        sage: from sage.interfaces.khoca import khoca_interface
+        sage: khoca_interface(ZZ)
+        Khovanov homology calculator for Frobenius algebra: Z[X] / (1*X^2).
+        sage: khoca_interface(QQ)
+        Khovanov homology calculator for Frobenius algebra: Q[X] / (1*X^2).
+        sage: khoca_interface(GF(3))
+        Khovanov homology calculator for Frobenius algebra: F_3[X] / (1*X^2).
+        sage: khoca_interface(ZZ, frobenius_algebra=(1,-2), root=1)
+        Khovanov homology calculator for Frobenius algebra: Z[X] / (1*X^2 + -2*X + 1).
+        sage: khoca_interface(QQ, equivariant=3)
+        Traceback (most recent call last):
+        ...
+        NotImplementedError: keyword equivariant is not implemented yet
     """
     from sage.features.khoca import Khoca
     Khoca().require()

src/sage/knots/link.py

@@ -1259,7 +1259,7 @@ def khovanov_homology(self, ring=ZZ, height=None, degree=None, implementation='n
           * ``'Khoca'`` -- uses the implementation of the optional package
             ``khoca``
 
-        - ``kwds`` -- dictionary of options to be passes to ``Khoca``
+        - ``kwds`` -- dictionary of options to be passed to ``Khoca``
 
           * ``reduced`` -- boolean (default ``False``); if
             ``True``, then returns the reduced homology
@@ -1275,6 +1275,7 @@ def khovanov_homology(self, ring=ZZ, height=None, degree=None, implementation='n
           * ``root`` -- integer specifying a root of the modulus of the
             Frobenius algeba
 
+
         OUTPUT:
 
         The Khovanov homology of the Link. It is given as a dictionary
@@ -1315,7 +1316,7 @@ def khovanov_homology(self, ring=ZZ, height=None, degree=None, implementation='n
             sage: K.khovanov_homology(base_ring=QQ)
             Traceback (most recent call last):
             ...
-            ValueError: 'base_ring' is not a valid KnownKeywords
+            ValueError: invalid keyword(s): ['base_ring']
 
         TESTS:
 
@@ -1348,6 +1349,8 @@ def khovanov_homology(self, ring=ZZ, height=None, degree=None, implementation='n
             check_kwds(**kwds)
         elif implementation != 'native':
             raise ValueError('%s is not a recognized implementation')
+        elif kwds:
+            raise ValueError(f"invalid keyword(s): {list(kwds)}")
 
         if not self.pd_code():  # special case for the unknot with no crossings
             from sage.homology.homology_group import HomologyGroup