Revert "bpo-26680: Incorporate is_integer in all built-in and standard library numeric types (GH-6121)" (GH-22584)

This reverts commit 58a7da9.

Author: rhettinger

Doc/library/decimal.rst

@@ -621,13 +621,6 @@ Decimal objects
       Return :const:`True` if the argument is either positive or negative
       infinity and :const:`False` otherwise.
 
-   .. method:: is_integer()
-
-      Return :const:`True` if the argument is a finite integral value and
-      :const:`False` otherwise.
-
-      .. versionadded:: 3.10
-
    .. method:: is_nan()
 
       Return :const:`True` if the argument is a (quiet or signaling) NaN and
@@ -1222,13 +1215,6 @@ In addition to the three supplied contexts, new contexts can be created with the
       Returns ``True`` if *x* is infinite; otherwise returns ``False``.
 
 
-   .. method:: is_integer(x)
-
-      Returns ``True`` if *x* is finite and integral; otherwise
-      returns ``False``.
-
-      .. versionadded:: 3.10
-
    .. method:: is_nan(x)
 
       Returns ``True`` if *x* is a qNaN or sNaN; otherwise returns ``False``.

Doc/library/numbers.rst

@@ -49,30 +49,19 @@ The numeric tower
    numbers.
 
    In short, those are: a conversion to :class:`float`, :func:`math.trunc`,
-   :func:`round`, :func:`math.floor`, :func:`math.ceil`, :func:`divmod`,
-   :func:`~Real.is_integer`, ``//``, ``%``, ``<``, ``<=``, ``>``, and ``>=``.
+   :func:`round`, :func:`math.floor`, :func:`math.ceil`, :func:`divmod`, ``//``,
+   ``%``, ``<``, ``<=``, ``>``, and ``>=``.
 
    Real also provides defaults for :func:`complex`, :attr:`~Complex.real`,
    :attr:`~Complex.imag`, and :meth:`~Complex.conjugate`.
 
-   .. method:: is_integer()
-
-      Returns :const:`True` if this number has a finite and integral value,
-      otherwise :const:`False`.  This is a default implementation which
-      relies on successful conversion to :class:`int`. It may be overridden
-      in subclasses (such as it is in :class:`float`) for better performance,
-      or to handle special values such as NaN which are not
-      convertible to :class:`int`.
-
-      .. versionadded:: 3.10
-
 
 .. class:: Rational
 
    Subtypes :class:`Real` and adds
    :attr:`~Rational.numerator` and :attr:`~Rational.denominator` properties, which
-   should be in lowest terms. With these, it provides defaults for
-   :func:`float` and :func:`~Real.is_integer`.
+   should be in lowest terms. With these, it provides a default for
+   :func:`float`.
 
    .. attribute:: numerator
 
@@ -86,10 +75,9 @@ The numeric tower
 .. class:: Integral
 
    Subtypes :class:`Rational` and adds a conversion to :class:`int`.  Provides
-   defaults for :func:`float`, :attr:`~Rational.numerator`,
-   :attr:`~Rational.denominator`, and :func:`~Real.is_integer`.  Adds abstract
-   methods for ``**`` and bit-string operations: ``<<``, ``>>``, ``&``, ``^``,
-   ``|``, ``~``.
+   defaults for :func:`float`, :attr:`~Rational.numerator`, and
+   :attr:`~Rational.denominator`.  Adds abstract methods for ``**`` and
+   bit-string operations: ``<<``, ``>>``, ``&``, ``^``, ``|``, ``~``.
 
 
 Notes for type implementors

Doc/library/stdtypes.rst

@@ -310,10 +310,6 @@ the operations, see :ref:`operator-summary`):
 +---------------------+---------------------------------+---------+--------------------+
 | ``x ** y``          | *x* to the power *y*            | \(5)    |                    |
 +---------------------+---------------------------------+---------+--------------------+
-| ``x.is_integer()``  | ``True`` if *x* has a finite    |         | :func:`~numbers\   |
-|                     | and integral value, otherwise   |         | .Real.is_integer`  |
-|                     | ``False``.                      |         |                    |
-+---------------------+---------------------------------+---------+--------------------+
 
 .. index::
    triple: operations on; numeric; types
@@ -587,6 +583,16 @@ class`. float also has the following additional methods.
    :exc:`OverflowError` on infinities and a :exc:`ValueError` on
    NaNs.
 
+.. method:: float.is_integer()
+
+   Return ``True`` if the float instance is finite with integral
+   value, and ``False`` otherwise::
+
+      >>> (-2.0).is_integer()
+      True
+      >>> (3.2).is_integer()
+      False
+
 Two methods support conversion to
 and from hexadecimal strings.  Since Python's floats are stored
 internally as binary numbers, converting a float to or from a

Lib/_pydecimal.py

@@ -3164,12 +3164,6 @@ def is_zero(self):
         """Return True if self is a zero; otherwise return False."""
         return not self._is_special and self._int == '0'
 
-    def is_integer(self):
-        """Return True is self is finite and integral; otherwise False."""
-        if self._is_special:
-            return False
-        return self.to_integral_value(rounding=ROUND_FLOOR) == self
-
     def _ln_exp_bound(self):
         """Compute a lower bound for the adjusted exponent of self.ln().
         In other words, compute r such that self.ln() >= 10**r.  Assumes
@@ -4665,25 +4659,6 @@ def is_zero(self, a):
         a = _convert_other(a, raiseit=True)
         return a.is_zero()
 
-    def is_integer(self, a):
-        """Return True if the operand is integral; otherwise return False.
-
-        >>> ExtendedContext.is_integer(Decimal('0'))
-        True
-        >>> ExtendedContext.is_integer(Decimal('2.50'))
-        False
-        >>> ExtendedContext.is_integer(Decimal('-0E+2'))
-        True
-        >>> ExtendedContext.is_integer(Decimal('-0.5'))
-        False
-        >>> ExtendedContext.is_integer(Decimal('NaN'))
-        False
-        >>> ExtendedContext.is_integer(10)
-        True
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_integer()
-
     def ln(self, a):
         """Returns the natural (base e) logarithm of the operand.
 

Lib/numbers.py

@@ -148,7 +148,7 @@ class Real(Complex):
     """To Complex, Real adds the operations that work on real numbers.
 
     In short, those are: a conversion to float, trunc(), divmod,
-    is_integer, %, <, <=, >, and >=.
+    %, <, <=, >, and >=.
 
     Real also provides defaults for the derived operations.
     """
@@ -242,17 +242,6 @@ def __le__(self, other):
         """self <= other"""
         raise NotImplementedError
 
-    def is_integer(self):
-        """Return True if the Real is integral; otherwise return False.
-
-        This default implementation can be overridden in subclasses
-        for performance reasons or to deal with values such as NaN,
-        which would otherwise cause an exception to be raised.
-        """
-        # Although __int__ is not defined at this level, the int
-        # constructor falls back to __trunc__, which we do have.
-        return self == int(self)
-
     # Concrete implementations of Complex abstract methods.
     def __complex__(self):
         """complex(self) == complex(float(self), 0)"""
@@ -301,10 +290,6 @@ def __float__(self):
         """
         return self.numerator / self.denominator
 
-    def is_integer(self):
-        """Return True if the Rational is integral; otherwise return False."""
-        return self.denominator == 1
-
 
 class Integral(Rational):
     """Integral adds a conversion to int and the bit-string operations."""
@@ -401,8 +386,4 @@ def denominator(self):
         """Integers have a denominator of 1."""
         return 1
 
-    def is_integer(self):
-        """Return True; all Integrals represent an integral value."""
-        return True
-
 Integral.register(int)

Lib/test/decimaltestdata/extra.decTest

@@ -2346,24 +2346,6 @@ bool2096 iszero sNaN -> 0
 bool2097 iszero -sNaN -> 0
 bool2098 iszero sNaN123 -> 0
 bool2099 iszero -sNaN123 -> 0
-bool2100 is_integer -1.0 -> 1
-bool2101 is_integer 0.0 -> 1
-bool2102 is_integer 1.0 -> 1
-bool2103 is_integer 42 -> 1
-bool2104 is_integer 1e2 -> 1
-bool2105 is_integer 1.5 -> 0
-bool2106 is_integer 1e-2 -> 0
-bool2107 is_integer NaN -> 0
-bool2109 is_integer -NaN -> 0
-bool2110 is_integer NaN123 -> 0
-bool2111 is_integer -NaN123 -> 0
-bool2112 is_integer sNaN -> 0
-bool2113 is_integer -sNaN -> 0
-bool2114 is_integer sNaN123 -> 0
-bool2115 is_integer -sNaN123 -> 0
-bool2116 is_integer Infinity -> 0
-bool2117 is_integer -Infinity -> 0
-
 
 ------------------------------------------------------------------------
 -- The following tests (pwmx0 through pwmx440) are for the            --

Lib/test/test_bool.py

@@ -354,11 +354,6 @@ def test_real_and_imag(self):
         self.assertIs(type(False.real), int)
         self.assertIs(type(False.imag), int)
 
-    def test_always_is_integer(self):
-        # Issue #26680: Incorporating number.is_integer into bool
-        self.assertTrue(all(b.is_integer() for b in (False, True)))
-
-
 def test_main():
     support.run_unittest(BoolTest)
 

Lib/test/test_decimal.py

@@ -276,7 +276,6 @@ def setUp(self):
                                  'is_snan',
                                  'is_subnormal',
                                  'is_zero',
-                                 'is_integer',
                                  'same_quantum')
 
     def read_unlimited(self, v, context):
@@ -2727,7 +2726,6 @@ def test_named_parameters(self):
             self.assertRaises(TypeError, D(1).is_snan, context=xc)
             self.assertRaises(TypeError, D(1).is_signed, context=xc)
             self.assertRaises(TypeError, D(1).is_zero, context=xc)
-            self.assertRaises(TypeError, D(1).is_integer, context=xc)
 
             self.assertFalse(D("0.01").is_normal(context=xc))
             self.assertTrue(D("0.01").is_subnormal(context=xc))
@@ -3199,15 +3197,6 @@ def test_is_zero(self):
         self.assertEqual(c.is_zero(10), d)
         self.assertRaises(TypeError, c.is_zero, '10')
 
-    def test_is_integer(self):
-        Decimal = self.decimal.Decimal
-        Context = self.decimal.Context
-
-        c = Context()
-        b = c.is_integer(Decimal(10))
-        self.assertEqual(c.is_integer(10), b)
-        self.assertRaises(TypeError, c.is_integer, '10')
-
     def test_ln(self):
         Decimal = self.decimal.Decimal
         Context = self.decimal.Context
@@ -4371,19 +4360,6 @@ def test_implicit_context(self):
             self.assertTrue(Decimal("-1").is_signed())
             self.assertTrue(Decimal("0").is_zero())
             self.assertTrue(Decimal("0").is_zero())
-            self.assertTrue(Decimal("-1").is_integer())
-            self.assertTrue(Decimal("0").is_integer())
-            self.assertTrue(Decimal("1").is_integer())
-            self.assertTrue(Decimal("42").is_integer())
-            self.assertTrue(Decimal("1e2").is_integer())
-            self.assertFalse(Decimal("1.5").is_integer())
-            self.assertFalse(Decimal("1e-2").is_integer())
-            self.assertFalse(Decimal("NaN").is_integer())
-            self.assertFalse(Decimal("-NaN").is_integer())
-            self.assertFalse(Decimal("sNaN").is_integer())
-            self.assertFalse(Decimal("-sNaN").is_integer())
-            self.assertFalse(Decimal("Inf").is_integer())
-            self.assertFalse(Decimal("-Inf").is_integer())
 
         # Copy
         with localcontext() as c:

Lib/test/test_fractions.py

@@ -724,17 +724,6 @@ def denominator(self):
         self.assertEqual(type(f.numerator), myint)
         self.assertEqual(type(f.denominator), myint)
 
-    def test_is_integer(self):
-        # Issue #26680: Incorporating number.is_integer into Fraction
-        self.assertTrue(F(-1, 1).is_integer())
-        self.assertTrue(F(0, 1).is_integer())
-        self.assertTrue(F(1, 1).is_integer())
-        self.assertTrue(F(42, 1).is_integer())
-        self.assertTrue(F(2, 2).is_integer())
-        self.assertTrue(F(8, 4).is_integer())
-        self.assertFalse(F(1, 2).is_integer())
-        self.assertFalse(F(1, 3).is_integer())
-        self.assertFalse(F(2, 3).is_integer())
 
 if __name__ == '__main__':
     unittest.main()

Lib/test/test_long.py

@@ -1381,10 +1381,6 @@ class myint(int):
             self.assertEqual(type(numerator), int)
             self.assertEqual(type(denominator), int)
 
-    def test_int_always_is_integer(self):
-        # Issue #26680: Incorporating number.is_integer into int
-        self.assertTrue(all(x.is_integer() for x in (-1, 0, 1, 42)))
-
 
 if __name__ == "__main__":
     unittest.main()