changing some Cannot to cannot in error messages

Author: fchapoton

src/sage/combinat/alternating_sign_matrix.py

@@ -1196,7 +1196,7 @@ def _element_constructor_(self, asm, check=True):
         if isinstance(asm, AlternatingSignMatrix):
             if asm.parent() is self:
                 return asm
-            raise ValueError("Cannot convert between alternating sign matrices of different sizes")
+            raise ValueError("cannot convert between alternating sign matrices of different sizes")
         try:
             m = self._matrix_space(asm)
         except (TypeError, ValueError):

src/sage/combinat/decorated_permutation.py

@@ -212,7 +212,7 @@ def _element_constructor_(self, pi, check=True):
         if isinstance(pi, DecoratedPermutation):
             if pi.parent() is self:
                 return pi
-            raise ValueError("Cannot convert between decorated permutations of different sizes")
+            raise ValueError("cannot convert between decorated permutations of different sizes")
 
         pi = tuple(pi)
         if check and pi not in self:

src/sage/combinat/derangements.py

@@ -198,7 +198,7 @@ def _element_constructor_(self, der):
         if isinstance(der, Derangement):
             if der.parent() is self:
                 return der
-            raise ValueError("Cannot convert %s to an element of %s" % (der, self))
+            raise ValueError("cannot convert %s to an element of %s" % (der, self))
         return self.element_class(self, der)
 
     Element = Derangement

src/sage/combinat/posets/posets.py

@@ -1603,7 +1603,7 @@ def linear_extensions(self, facade=False):
                 sage: L([1, 2, 3, 4, 6, 12])
                 Traceback (most recent call last):
                 ...
-                TypeError: Cannot convert list to sage.structure.element.Element
+                TypeError: cannot convert list to sage.structure.element.Element
 
         EXAMPLES::
 

src/sage/cpython/wrapperdescr.pxd

@@ -59,6 +59,6 @@ cdef inline wrapperbase* get_slotdef(wrapper_descriptor slotwrapper) except NULL
         sage: py_get_slotdef(X.__eq__)
         Traceback (most recent call last):
         ...
-        TypeError: Cannot convert ... to wrapper_descriptor
+        TypeError: cannot convert ... to wrapper_descriptor
     """
     return slotwrapper.d_base

src/sage/data_structures/bounded_integer_sequences.pyx

@@ -1208,11 +1208,11 @@ cdef class BoundedIntegerSequence:
             sage: T+list(S)
             Traceback (most recent call last):
             ...
-            TypeError: Cannot convert list to sage.data_structures.bounded_integer_sequences.BoundedIntegerSequence
+            TypeError: cannot convert list to sage.data_structures.bounded_integer_sequences.BoundedIntegerSequence
             sage: T+None
             Traceback (most recent call last):
             ...
-            TypeError: Cannot concatenate bounded integer sequence and None
+            TypeError: cannot concatenate bounded integer sequence and None
 
         TESTS:
 
@@ -1228,7 +1228,7 @@ cdef class BoundedIntegerSequence:
         """
         cdef BoundedIntegerSequence myself, right, out
         if other is None or self is None:
-            raise TypeError('Cannot concatenate bounded integer sequence and None')
+            raise TypeError('cannot concatenate bounded integer sequence and None')
         myself = self  # may result in a type error
         right = other  #  --"--
         if right.data.itembitsize != myself.data.itembitsize:

src/sage/geometry/lattice_polytope.py

@@ -5251,8 +5251,8 @@ def from_palp_index(i):
             elif o in range(65, 91):
                 i = o - 28
             else:
-                raise ValueError('Cannot convert PALP index '
-                                 + i + ' to number.')
+                raise ValueError('cannot convert PALP index '
+                                 + i + ' to number')
         return i
     n = len(permutation)
     domain = [from_palp_index(i) for i in permutation]
@@ -5261,6 +5261,7 @@ def from_palp_index(i):
     S = SymmetricGroup(n)
     return make_permgroup_element(S, domain)
 
+
 def _read_nef_x_partitions(data):
     r"""
     Read all nef-partitions for one polytope from a string or an open

src/sage/geometry/polyhedron/parent.py

@@ -697,7 +697,7 @@ def convert_base_ring_Hrep(lstlst):
             return self._element_constructor_polyhedron(polyhedron, mutable=mutable, **kwds)
         if nargs == 1 and args[0] == 0:
             return self.zero()
-        raise ValueError('Cannot convert to polyhedron object.')
+        raise ValueError('cannot convert to polyhedron object')
 
     def _element_constructor_polyhedron(self, polyhedron, **kwds):
         """

src/sage/graphs/generic_graph.py

@@ -2414,7 +2414,7 @@ def weighted_adjacency_matrix(self, sparse=True, vertices=None,
             sage: G.weighted_adjacency_matrix()
             Traceback (most recent call last):
             ...
-            TypeError: Cannot convert NoneType to sage.structure.parent.Parent
+            TypeError: cannot convert NoneType to sage.structure.parent.Parent
         """
         if self.has_multiple_edges():
             raise NotImplementedError("don't know how to represent weights for a multigraph")

src/sage/libs/giac/giac.pyx

@@ -1409,7 +1409,7 @@ cdef class Pygen(GiacMethods_base):
             return result
 
         else:
-            raise TypeError("Cannot convert non giac integers to Integer")
+            raise TypeError("cannot convert non giac integers to Integer")
 
 
     def _rational_(self,Z=None):
@@ -1434,7 +1434,7 @@ cdef class Pygen(GiacMethods_base):
             # giac _RAT_
             return ZZ(self.numer()) / ZZ(self.denom())
         else:
-            raise TypeError("Cannot convert non giac _FRAC_ to QQ")
+            raise TypeError("cannot convert non giac _FRAC_ to QQ")
 
 
     def sage(self):
@@ -1736,7 +1736,7 @@ cdef class Pygen(GiacMethods_base):
                 sig_off()
                 return result
             else:
-                raise TypeError("Cannot convert non _INT_ giac gen")
+                raise TypeError("cannot convert non _INT_ giac gen")
 
 
     property _double:  # immediate double (type _DOUBLE_)
@@ -1750,7 +1750,7 @@ cdef class Pygen(GiacMethods_base):
                 sig_off()
                 return result
             else:
-                raise TypeError("Cannot convert non _DOUBLE_ giac gen")
+                raise TypeError("cannot convert non _DOUBLE_ giac gen")
 
     property help:
         def __get__(self):