Trac #28000: Get rid of most __nonzero__ references and/or replace th…

…em with __bool__

src/sage/algebras/commutative_dga.py

@@ -549,7 +549,7 @@ def _is_nonzero(self):
         """
         Return ``True`` iff this morphism is nonzero.
 
-        This is used by the :meth:`Morphism.__nonzero__` method, which
+        This is used by the :meth:`Morphism.__bool__` method, which
         in turn is used by the :func:`TestSuite` test
         ``_test_nonzero_equal``.
 

src/sage/algebras/jordan_algebra.py

@@ -415,8 +415,6 @@ def __bool__(self):
             """
             return bool(self._x)
 
-        __nonzero__ = __bool__
-
         def __eq__(self, other):
             """
             Check equality.
@@ -820,8 +818,6 @@ def __bool__(self):
             """
             return bool(self._s) or bool(self._v)
 
-        __nonzero__ = __bool__
-
         def __eq__(self, other):
             """
             Check equality.

src/sage/algebras/letterplace/free_algebra_element_letterplace.pyx

@@ -397,7 +397,7 @@ cdef class FreeAlgebraElement_letterplace(AlgebraElement):
         """
         return self._poly.lc()
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         TESTS::
 

src/sage/algebras/lie_algebras/classical_lie_algebra.py

@@ -1175,8 +1175,6 @@ def __bool__(self):
             """
             return bool(self._real) or bool(self._imag)
 
-        __nonzero__ = __bool__
-
         def __hash__(self):
             r"""
             Return the hash of ``self``.

src/sage/algebras/lie_algebras/lie_algebra_element.pyx

@@ -301,7 +301,7 @@ cdef class LieAlgebraElementWrapper(ElementWrapper):
         from sage.typeset.unicode_art import unicode_art
         return unicode_art(self.value)
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         Return if ``self`` is non-zero.
 
@@ -1126,7 +1126,7 @@ cdef class UntwistedAffineLieAlgebraElement(Element):
                                self._c_coeff, self._d_coeff))
         return self._hash
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         Return ``self`` as a boolean.
 

src/sage/algebras/quatalg/quaternion_algebra_element.pyx

@@ -345,7 +345,7 @@ cdef class QuaternionAlgebraElement_abstract(AlgebraElement):
             return Rational(self[0])
         raise TypeError
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         Return ``True`` if this quaternion is nonzero.
 
@@ -948,7 +948,7 @@ cdef class QuaternionAlgebraElement_rational_field(QuaternionAlgebraElement_abst
         """
         return not (mpz_sgn(self.y) or mpz_sgn(self.z) or mpz_sgn(self.w))
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         Return True if this quaternion is nonzero.
 

src/sage/categories/category.py

@@ -1767,10 +1767,7 @@ def required_methods(self):
 
         EXAMPLES::
 
-            sage: Algebras(QQ).required_methods() # py2
-            {'element': {'optional': ['_add_', '_mul_'], 'required': ['__nonzero__']},
-             'parent': {'optional': ['algebra_generators'], 'required': ['__contains__']}}
-            sage: Algebras(QQ).required_methods() # py3
+            sage: Algebras(QQ).required_methods()
             {'element': {'optional': ['_add_', '_mul_'], 'required': ['__bool__']},
              'parent': {'optional': ['algebra_generators'], 'required': ['__contains__']}}
         """

src/sage/categories/crystals.py

@@ -2196,8 +2196,6 @@ def __bool__(self):
         """
         return any(self._on_gens(mg) is not None for mg in self._gens)
 
-    __nonzero__ = __bool__
-
     # TODO: Does this belong in the element_class of the Crystals() category?
     def to_module_generator(self, x):
         """

src/sage/categories/examples/commutative_additive_monoids.py

@@ -126,6 +126,5 @@ def __bool__(self):
             """
             return any(x for x in self.value.values())
 
-        __nonzero__ = __bool__
 
 Example = FreeCommutativeAdditiveMonoid

src/sage/categories/examples/lie_algebras.py

@@ -207,8 +207,6 @@ def __bool__(self):
             """
             return bool(self.value)
 
-        __nonzero__ = __bool__
-
         def _add_(self, rhs):
             """
             Add ``self`` and ``rhs``.

src/sage/categories/homset.py

@@ -746,8 +746,6 @@ def __bool__(self):
         """
         return True
 
-    __nonzero__ = __bool__
-
     def homset_category(self):
         """
         Return the category that this is a Hom in, i.e., this is typically
@@ -1086,7 +1084,7 @@ def __ne__(self, other):
             True
         """
         return not (self == other)
-    
+
     def __contains__(self, x):
         """
         Test whether the parent of the argument is ``self``.

src/sage/categories/morphism.pyx

@@ -375,7 +375,7 @@ cdef class Morphism(Map):
             domain = <Parent?>base
         return rich_to_bool(op, 0)
 
-    def __nonzero__(self):
+    def __bool__(self):
         r"""
         Return whether this morphism is not a zero morphism.
 
@@ -397,10 +397,7 @@ cdef class Morphism(Map):
         try:
             return self._is_nonzero()
         except Exception:
-            if PY_MAJOR_VERSION < 3:
-                return super(Morphism, self).__nonzero__()
-            else:
-                return super().__bool__()
+            return super().__bool__()
 
 
 cdef class FormalCoercionMorphism(Morphism):

src/sage/categories/rings.py

@@ -182,7 +182,7 @@ def _is_nonzero(self):
             .. NOTE::
 
                 We can not override ``is_zero()`` from the category framework
-                and we can not implement ``__nonzero__`` because it is a
+                and we can not implement ``__bool__`` because it is a
                 special method. That this is why this has a cumbersome name.
 
             EXAMPLES::

src/sage/combinat/combinat.py

@@ -1291,8 +1291,6 @@ def __bool__(self):
         """
         return bool(self._list)
 
-    __nonzero__ = __bool__
-
     def __len__(self):
         """
         EXAMPLES::

src/sage/combinat/crystals/kirillov_reshetikhin.py

@@ -4162,4 +4162,3 @@ def is_isomorphism(self):
     is_embedding = is_isomorphism
     is_strict = is_isomorphism
     __bool__ = is_isomorphism
-    __nonzero__ = is_isomorphism

src/sage/combinat/finite_state_machine.py

@@ -2035,10 +2035,6 @@ def __bool__(self):
         """
         return True  # A state cannot be zero (see __init__)
 
-
-    __nonzero__ = __bool__
-
-
     def _epsilon_successors_(self, fsm=None):
         """
         Returns the dictionary with states reachable from ``self``
@@ -2540,8 +2536,6 @@ def __bool__(self):
         """
         return True  # A transition cannot be zero (see __init__)
 
-    __nonzero__ = __bool__
-
 
 #*****************************************************************************
 
@@ -4005,8 +3999,6 @@ def __bool__(self):
         """
         return bool(self._states_)
 
-    __nonzero__ = __bool__
-
     def __eq__(left, right):
         """
         Returns ``True`` if the two finite state machines are equal,

src/sage/combinat/rigged_configurations/rigged_partition.pyx

@@ -290,7 +290,7 @@ cdef class RiggedPartition(SageObject):
             self._hash = hash(tuple(self._list))
         return self._hash
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         TESTS::
 

src/sage/combinat/words/word_char.pyx

@@ -122,7 +122,7 @@ cdef class WordDatatype_char(WordDatatype):
         if self._is_slice == 0:
             sig_free(self._data)
 
-    def __nonzero__(self):
+    def __bool__(self):
         r"""
         Test whether the word is not empty.
 

src/sage/cpython/debugimpl.c

@@ -240,11 +240,7 @@ static void _type_debug(PyTypeObject* tp)
         subattr_pointer_meth(tp_as_number, nb_negative, "__neg__");
         subattr_pointer_meth(tp_as_number, nb_positive, "__pos__");
         subattr_pointer_meth(tp_as_number, nb_absolute, "__abs__");
-        #if PY_MAJOR_VERSION <= 2
-            subattr_pointer_meth(tp_as_number, nb_nonzero, "__nonzero__");
-        #else
-            subattr_pointer_meth(tp_as_number, nb_bool, "__bool__");
-        #endif
+        subattr_pointer_meth(tp_as_number, nb_bool, "__bool__");
         subattr_pointer_meth(tp_as_number, nb_invert, "__invert__");
         subattr_pointer_meth(tp_as_number, nb_lshift, "__lshift__");
         subattr_pointer_meth(tp_as_number, nb_rshift, "__rshift__");

src/sage/data_structures/bounded_integer_sequences.pyx

@@ -769,7 +769,7 @@ cdef class BoundedIntegerSequence:
         """
         return self.data.length
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         A bounded integer sequence is nonzero if and only if its length is nonzero.
 

src/sage/features/__init__.py

@@ -326,8 +326,6 @@ def __bool__(self):
         """
         return bool(self.is_present)
 
-    __nonzero__ = __bool__
-
     def __repr__(self):
         r"""
         TESTS::

src/sage/groups/abelian_gps/abelian_group.py

@@ -672,8 +672,6 @@ def __bool__(self):
         """
         return not self.is_trivial()
 
-    __nonzero__ = __bool__
-
     @cached_method
     def dual_group(self, names="X", base_ring=None):
         """

src/sage/interfaces/fricas.py

@@ -1009,8 +1009,6 @@ def __bool__(self):
         P = self._check_valid()
         return not P.new("zero?(%s)" % self._name).sage()
 
-    __nonzero__ = __bool__
-
     def __long__(self):
         """
         TESTS::

src/sage/interfaces/interface.py

@@ -1321,8 +1321,6 @@ def __bool__(self):
                             P._false_symbol())
         return P.eval(cmd) != P._true_symbol()
 
-    __nonzero__ = __bool__
-
     def __long__(self):
         """
         EXAMPLES::

src/sage/interfaces/macaulay2.py

@@ -1157,8 +1157,6 @@ def __bool__(self):
         P = self.parent()
         return P.eval('{0}===false or {0}==0'.format(self._name)) != 'true'
 
-    __nonzero__ = __bool__
-
     def sage_polystring(self):
         """
         If this Macaulay2 element is a polynomial, return a string

src/sage/interfaces/magma.py

@@ -2624,8 +2624,6 @@ def __bool__(self):
                 pass
         return True
 
-    __nonzero__ = __bool__
-
     def sub(self, gens):
         """
         Return the sub-object of self with given gens.

src/sage/interfaces/octave.py

@@ -660,8 +660,6 @@ def __bool__(self):
         """
         return str(self) != ' [](0x0)' and any(x != '0' for x in str(self).split())
 
-    __nonzero__ = __bool__
-
     def _matrix_(self, R=None):
         r"""
         Return Sage matrix from this octave element.

src/sage/interfaces/r.py

@@ -1615,8 +1615,6 @@ def __bool__(self):
         """
         return "FALSE" in repr(self==0)
 
-    __nonzero__ = __bool__
-
     def _comparison(self, other, symbol):
         """
         Used to implement comparison of two objects.

src/sage/interfaces/singular.py

@@ -1443,8 +1443,6 @@ def __bool__(self):
         P = self.parent()
         return P.eval('%s == 0' % self.name()) == '0'
 
-    __nonzero__ = __bool__
-
     def sage_polystring(self):
         r"""
         If this Singular element is a polynomial, return a string

src/sage/libs/gap/element.pyx

@@ -2261,7 +2261,7 @@ cdef class GapElement_Boolean(GapElement):
             return False
         raise ValueError('the GAP boolean value "fail" cannot be represented in Sage')
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         Check that the boolean is "true".
 
@@ -2275,12 +2275,12 @@ cdef class GapElement_Boolean(GapElement):
 
             sage: gap_bool = [libgap.eval('true'), libgap.eval('false'), libgap.eval('fail')]
             sage: for x in gap_bool:
-            ....:     if x:     # this calls __nonzero__
+            ....:     if x:     # this calls __bool__
             ....:         print("{} {}".format(x, type(x)))
             true <type 'sage.libs.gap.element.GapElement_Boolean'>
 
             sage: for x in gap_bool:
-            ....:     if not x:     # this calls __nonzero__
+            ....:     if not x:     # this calls __bool__
             ....:         print("{} {}".format( x, type(x)))
             false <type 'sage.libs.gap.element.GapElement_Boolean'>
             fail <type 'sage.libs.gap.element.GapElement_Boolean'>

src/sage/libs/mpmath/ext_main.pyx

@@ -1927,7 +1927,7 @@ cdef class mpf(mpf_base):
 
     _mpf_ = property(_get_mpf, _set_mpf, doc=_get_mpf.__doc__)
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         Returns whether the number is nonzero ::
 
@@ -2273,7 +2273,7 @@ cdef class constant(mpf_base):
             return str(self)
         return "<%s: %s~>" % (self.name, global_context.nstr(self))
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         Returns whether the constant is nonzero ::
 
@@ -2457,7 +2457,7 @@ cdef class mpc(mpnumber):
         """
         return "(%s)" % libmp.mpc_to_str(s._mpc_, global_context._str_digits)
 
-    def __nonzero__(self):
+    def __bool__(self):
         """
         TESTS ::
 

src/sage/manifolds/chart_func.py

@@ -805,8 +805,6 @@ def __bool__(self):
             val = self.expr(curr).is_zero
         return not val
 
-    __nonzero__ = __bool__   # For Python2 compatibility
-
     def is_trivial_zero(self):
         r"""
         Check if ``self`` is trivially equal to zero without any

src/sage/manifolds/differentiable/mixed_form.py

@@ -541,8 +541,6 @@ def __bool__(self):
         self._is_zero = True
         return False
 
-    __nonzero__ = __bool__  # For Python2 compatibility
-
     def _richcmp_(self, other, op):
         r"""
         Comparison method for sage objects.