Raise TypeError instead of ValueError.

Author: serhiy-storchaka

Doc/library/random.rst

@@ -135,6 +135,10 @@ Functions for integers
  values. Formerly it used a style like ``int(random()*n)`` which could produce
  slightly uneven distributions.
 
+ .. versionchanged:: 3.10
+ Formerly :exc:`ValueError` could be raised for non-integer arguments
+ instead of :exc:`TypeError`.
+
  .. deprecated:: 3.10
  Accepting non-integer arguments is deprecated.
 

Lib/random.py

@@ -303,7 +303,7 @@ def randrange(self, start, stop=None, step=1):
  except TypeError:
  istart = int(start)
  if istart != start:
- raise ValueError("non-integer arg 1 for randrange()")
+ raise TypeError("non-integer arg 1 for randrange()")
  _warn('non-integer arg 1 for randrange()',
  DeprecationWarning, 2)
  if stop is None:
@@ -317,7 +317,7 @@ def randrange(self, start, stop=None, step=1):
  except TypeError:
  istop = int(stop)
  if istop != stop:
- raise ValueError("non-integer stop for randrange()")
+ raise TypeError("non-integer stop for randrange()")
  _warn('non-integer stop for randrange()',
  DeprecationWarning, 2)
  width = istop - istart
@@ -326,7 +326,7 @@ def randrange(self, start, stop=None, step=1):
  except TypeError:
  istep = int(step)
  if istep != step:
- raise ValueError("non-integer step for randrange()")
+ raise TypeError("non-integer step for randrange()")
  _warn('non-integer step for randrange()',
  DeprecationWarning, 2)
  # Fast path.

Lib/test/test_random.py

@@ -504,28 +504,40 @@ def test_randrange_nonunit_step(self):
  rint = self.gen.randrange(0, 2, 2)
  self.assertEqual(rint, 0)
 
+ def test_randrange_non_integers(self):
+ randrange = self.gen.randrange
+ with self.assertWarns(DeprecationWarning):
+ self.assertIn(randrange(3.0), range(3))
+ with self.assertWarns(DeprecationWarning):
+ self.assertIn(randrange(0, 3.0), range(0, 3))
+ with self.assertWarns(DeprecationWarning):
+ self.assertIn(randrange(0, 42, 1.0), range(0, 42, 1))
+ with self.assertWarns(DeprecationWarning):
+ self.assertIn(randrange(0, 42, 3.0), range(0, 42, 3))
+
  def test_randrange_errors(self):
- raises = partial(self.assertRaises, ValueError, self.gen.randrange)
+ randrange = self.gen.randrange
+ raises = partial(self.assertRaises, ValueError, randrange)
  # Empty range
  raises(3, 3)
  raises(-721)
  raises(0, 100, -12)
  self.assertWarns(DeprecationWarning, raises, 3, 3, 1.0)
  # Non-integer start/stop
- raises(3.14159)
- self.assertWarns(DeprecationWarning, self.gen.randrange, 3.0)
- self.assertWarns(DeprecationWarning, self.gen.randrange, Fraction(3, 1))
- raises('3')
- raises(0, 2.71828)
- self.assertWarns(DeprecationWarning, self.gen.randrange, 0, 2.0)
- self.assertWarns(DeprecationWarning, self.gen.randrange, 0, Fraction(2, 1))
- raises(0, '2')
+ self.assertRaises(TypeError, randrange, 3.14159)
+ self.assertWarns(DeprecationWarning, randrange, 3.0)
+ self.assertWarns(DeprecationWarning, randrange, Fraction(3, 1))
+ self.assertRaises(TypeError, randrange, '3')
+ self.assertRaises(TypeError, randrange, 0, 2.71828)
+ self.assertWarns(DeprecationWarning, randrange, 0, 2.0)
+ self.assertWarns(DeprecationWarning, randrange, 0, Fraction(2, 1))
+ self.assertRaises(TypeError, randrange, 0, '2')
  # Zero and non-integer step
  raises(0, 42, 0)
- 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))
- raises(0, 42, '3')
+ self.assertRaises(TypeError, randrange, 0, 42, 3.14159)
+ self.assertWarns(DeprecationWarning, randrange, 0, 42, 3.0)
+ self.assertWarns(DeprecationWarning, randrange, 0, 42, Fraction(3, 1))
+ self.assertRaises(TypeError, randrange, 0, 42, '3')
 
  def test_randbelow_logic(self, _log=log, int=int):
  # check bitcount transition points: 2**i and 2**(i+1)-1

Misc/NEWS.d/next/Library/2020-03-22-21-33-31.bpo-37319.BrIAir.rst

@@ -1 +1,3 @@
 Deprecated support of non-integer arguments in :func:`random.randrange`.
+:exc:`TypeError` is now always raised for wrong type of arguments
+(formerly :exc:`ValueError` could be raised for some non-integer arguments).