bpo-42222: Remove deprecated support for non-integer values (GH-28983)

Author: rhettinger

Doc/library/random.rst

@@ -135,15 +135,10 @@ Functions for integers
       values.  Formerly it used a style like ``int(random()*n)`` which could produce
       slightly uneven distributions.
 
-   .. deprecated:: 3.10
-      The automatic conversion of non-integer types to equivalent integers is
-      deprecated.  Currently ``randrange(10.0)`` is losslessly converted to
-      ``randrange(10)``.  In the future, this will raise a :exc:`TypeError`.
-
-   .. deprecated:: 3.10
-      The exception raised for non-integral values such as ``randrange(10.5)``
-      or ``randrange('10')`` will be changed from :exc:`ValueError` to
-      :exc:`TypeError`.
+   .. versionchanged:: 3.11
+      Automatic conversion of non-integer types is no longer supported.
+      Calls such as ``randrange(10.0)`` and ``randrange(Fraction(10, 1))``
+      now raise a :exc:`TypeError`.
 
 .. function:: randint(a, b)
 

Lib/random.py

@@ -286,27 +286,17 @@ def randbytes(self, n):
     ## -------------------- integer methods  -------------------
 
     def randrange(self, start, stop=None, step=_ONE):
-        """Choose a random item from range(start, stop[, step]).
+        """Choose a random item from range(stop) or range(start, stop[, step]).
 
-        This fixes the problem with randint() which includes the
-        endpoint; in Python this is usually not what you want.
+        Roughly equivalent to ``choice(range(start, stop, step))``
+        but supports arbitrarily large ranges and is optimized
+        for common cases.
 
         """
 
         # This code is a bit messy to make it fast for the
         # common case while still doing adequate error checking.
-        try:
-            istart = _index(start)
-        except TypeError:
-            istart = int(start)
-            if istart != start:
-                _warn('randrange() will raise TypeError in the future',
-                      DeprecationWarning, 2)
-                raise ValueError("non-integer arg 1 for randrange()")
-            _warn('non-integer arguments to randrange() have been deprecated '
-                  'since Python 3.10 and will be removed in a subsequent '
-                  'version',
-                  DeprecationWarning, 2)
+        istart = _index(start)
         if stop is None:
             # We don't check for "step != 1" because it hasn't been
             # type checked and converted to an integer yet.
@@ -316,37 +306,15 @@ def randrange(self, start, stop=None, step=_ONE):
                 return self._randbelow(istart)
             raise ValueError("empty range for randrange()")
 
-        # stop argument supplied.
-        try:
-            istop = _index(stop)
-        except TypeError:
-            istop = int(stop)
-            if istop != stop:
-                _warn('randrange() will raise TypeError in the future',
-                      DeprecationWarning, 2)
-                raise ValueError("non-integer stop for randrange()")
-            _warn('non-integer arguments to randrange() have been deprecated '
-                  'since Python 3.10 and will be removed in a subsequent '
-                  'version',
-                  DeprecationWarning, 2)
+        # Stop argument supplied.
+        istop = _index(stop)
         width = istop - istart
-        try:
-            istep = _index(step)
-        except TypeError:
-            istep = int(step)
-            if istep != step:
-                _warn('randrange() will raise TypeError in the future',
-                      DeprecationWarning, 2)
-                raise ValueError("non-integer step for randrange()")
-            _warn('non-integer arguments to randrange() have been deprecated '
-                  'since Python 3.10 and will be removed in a subsequent '
-                  'version',
-                  DeprecationWarning, 2)
+        istep = _index(step)
         # Fast path.
         if istep == 1:
             if width > 0:
                 return istart + self._randbelow(width)
-            raise ValueError("empty range for randrange() (%d, %d, %d)" % (istart, istop, width))
+            raise ValueError(f"empty range in randrange({start}, {stop}, {step})")
 
         # Non-unit step argument supplied.
         if istep > 0:
@@ -356,7 +324,7 @@ def randrange(self, start, stop=None, step=_ONE):
         else:
             raise ValueError("zero step for randrange()")
         if n <= 0:
-            raise ValueError("empty range for randrange()")
+            raise ValueError(f"empty range in randrange({start}, {stop}, {step})")
         return istart + istep * self._randbelow(n)
 
     def randint(self, a, b):

Lib/test/test_random.py

@@ -481,50 +481,53 @@ def test_randrange_nonunit_step(self):
         self.assertEqual(rint, 0)
 
     def test_randrange_errors(self):
-        raises = partial(self.assertRaises, ValueError, self.gen.randrange)
+        raises_value_error = partial(self.assertRaises, ValueError, self.gen.randrange)
+        raises_type_error = partial(self.assertRaises, TypeError, self.gen.randrange)
+
         # Empty range
-        raises(3, 3)
-        raises(-721)
-        raises(0, 100, -12)
-        # Non-integer start/stop
-        self.assertWarns(DeprecationWarning, raises, 3.14159)
-        self.assertWarns(DeprecationWarning, self.gen.randrange, 3.0)
-        self.assertWarns(DeprecationWarning, self.gen.randrange, Fraction(3, 1))
-        self.assertWarns(DeprecationWarning, raises, '3')
-        self.assertWarns(DeprecationWarning, raises, 0, 2.71828)
-        self.assertWarns(DeprecationWarning, self.gen.randrange, 0, 2.0)
-        self.assertWarns(DeprecationWarning, self.gen.randrange, 0, Fraction(2, 1))
-        self.assertWarns(DeprecationWarning, raises, 0, '2')
-        # Zero and non-integer step
-        raises(0, 42, 0)
-        self.assertWarns(DeprecationWarning, raises, 0, 42, 0.0)
-        self.assertWarns(DeprecationWarning, raises, 0, 0, 0.0)
-        self.assertWarns(DeprecationWarning, raises, 0, 42, 3.14159)
-        self.assertWarns(DeprecationWarning, self.gen.randrange, 0, 42, 3.0)
-        self.assertWarns(DeprecationWarning, self.gen.randrange, 0, 42, Fraction(3, 1))
-        self.assertWarns(DeprecationWarning, raises, 0, 42, '3')
-        self.assertWarns(DeprecationWarning, self.gen.randrange, 0, 42, 1.0)
-        self.assertWarns(DeprecationWarning, raises, 0, 0, 1.0)
+        raises_value_error(3, 3)
+        raises_value_error(-721)
+        raises_value_error(0, 100, -12)
+
+        # Zero step
+        raises_value_error(0, 42, 0)
+
+        # Non-integer start/stop/step
+        raises_type_error(3.14159)
+        raises_type_error(3.0)
+        raises_type_error(Fraction(3, 1))
+        raises_type_error('3')
+        raises_type_error(0, 2.71827)
+        raises_type_error(0, 2.0)
+        raises_type_error(0, Fraction(2, 1))
+        raises_type_error(0, '2')
+
+        # Non-integer step
+        raises_type_error(0, 42, 1.0)
+        raises_type_error(0, 0, 1.0)
+        raises_type_error(0, 42, 3.14159)
+        raises_type_error(0, 42, 3.0)
+        raises_type_error(0, 42, Fraction(3, 1))
+        raises_type_error(0, 42, '3')
+        raises_type_error(0, 42, 1.0)
+        raises_type_error(0, 0, 1.0)
 
     def test_randrange_argument_handling(self):
         randrange = self.gen.randrange
-        with self.assertWarns(DeprecationWarning):
+        with self.assertRaises(TypeError):
             randrange(10.0, 20, 2)
-        with self.assertWarns(DeprecationWarning):
+        with self.assertRaises(TypeError):
             randrange(10, 20.0, 2)
-        with self.assertWarns(DeprecationWarning):
+        with self.assertRaises(TypeError):
             randrange(10, 20, 1.0)
-        with self.assertWarns(DeprecationWarning):
+        with self.assertRaises(TypeError):
             randrange(10, 20, 2.0)
-        with self.assertWarns(DeprecationWarning):
-            with self.assertRaises(ValueError):
-                randrange(10.5)
-        with self.assertWarns(DeprecationWarning):
-            with self.assertRaises(ValueError):
-                randrange(10, 20.5)
-        with self.assertWarns(DeprecationWarning):
-            with self.assertRaises(ValueError):
-                randrange(10, 20, 1.5)
+        with self.assertRaises(TypeError):
+            randrange(10.5)
+        with self.assertRaises(TypeError):
+            randrange(10, 20.5)
+        with self.assertRaises(TypeError):
+            randrange(10, 20, 1.5)
 
     def test_randrange_step(self):
         # bpo-42772: When stop is None, the step argument was being ignored.

Misc/NEWS.d/next/Library/2021-10-15-11-30-11.bpo-42222.hdHyac.rst

@@ -0,0 +1 @@
+Removed deprecated support for float arguments in *randrange()*.