Merge pull request #6901 from ShaharNaveh/update-decimal

Update `decimal` from 3.14.2

Lib/_pydecimal.py

@@ -38,10 +38,10 @@ __all__ = [
     'ROUND_FLOOR', 'ROUND_UP', 'ROUND_HALF_DOWN', 'ROUND_05UP',
 
     # Functions for manipulating contexts
-    'setcontext', 'getcontext', 'localcontext',
+    'setcontext', 'getcontext', 'localcontext', 'IEEEContext',
 
     # Limits for the C version for compatibility
-    'MAX_PREC',  'MAX_EMAX', 'MIN_EMIN', 'MIN_ETINY',
+    'MAX_PREC',  'MAX_EMAX', 'MIN_EMIN', 'MIN_ETINY', 'IEEE_CONTEXT_MAX_BITS',
 
     # C version: compile time choice that enables the thread local context (deprecated, now always true)
     'HAVE_THREADS',
@@ -83,10 +83,12 @@ if sys.maxsize == 2**63-1:
     MAX_PREC = 999999999999999999
     MAX_EMAX = 999999999999999999
     MIN_EMIN = -999999999999999999
+    IEEE_CONTEXT_MAX_BITS = 512
 else:
     MAX_PREC = 425000000
     MAX_EMAX = 425000000
     MIN_EMIN = -425000000
+    IEEE_CONTEXT_MAX_BITS = 256
 
 MIN_ETINY = MIN_EMIN - (MAX_PREC-1)
 
@@ -417,6 +419,27 @@ def localcontext(ctx=None, **kwargs):
     return ctx_manager
 
 
+def IEEEContext(bits, /):
+    """
+    Return a context object initialized to the proper values for one of the
+    IEEE interchange formats.  The argument must be a multiple of 32 and less
+    than IEEE_CONTEXT_MAX_BITS.
+    """
+    if bits <= 0 or bits > IEEE_CONTEXT_MAX_BITS or bits % 32:
+        raise ValueError("argument must be a multiple of 32, "
+                         f"with a maximum of {IEEE_CONTEXT_MAX_BITS}")
+
+    ctx = Context()
+    ctx.prec = 9 * (bits//32) - 2
+    ctx.Emax = 3 * (1 << (bits//16 + 3))
+    ctx.Emin = 1 - ctx.Emax
+    ctx.rounding = ROUND_HALF_EVEN
+    ctx.clamp = 1
+    ctx.traps = dict.fromkeys(_signals, False)
+
+    return ctx
+
+
 ##### Decimal class #######################################################
 
 # Do not subclass Decimal from numbers.Real and do not register it as such
@@ -582,6 +605,21 @@ class Decimal(object):
 
         raise TypeError("Cannot convert %r to Decimal" % value)
 
+    @classmethod
+    def from_number(cls, number):
+        """Converts a real number to a decimal number, exactly.
+
+        >>> Decimal.from_number(314)              # int
+        Decimal('314')
+        >>> Decimal.from_number(0.1)              # float
+        Decimal('0.1000000000000000055511151231257827021181583404541015625')
+        >>> Decimal.from_number(Decimal('3.14'))  # another decimal instance
+        Decimal('3.14')
+        """
+        if isinstance(number, (int, Decimal, float)):
+            return cls(number)
+        raise TypeError("Cannot convert %r to Decimal" % number)
+
     @classmethod
     def from_float(cls, f):
         """Converts a float to a decimal number, exactly.
@@ -2425,12 +2463,12 @@ class Decimal(object):
 
         return ans
 
-    def __rpow__(self, other, context=None):
+    def __rpow__(self, other, modulo=None, context=None):
         """Swaps self/other and returns __pow__."""
         other = _convert_other(other)
         if other is NotImplemented:
             return other
-        return other.__pow__(self, context=context)
+        return other.__pow__(self, modulo, context=context)
 
     def normalize(self, context=None):
         """Normalize- strip trailing 0s, change anything equal to 0 to 0e0"""
@@ -3302,7 +3340,10 @@ class Decimal(object):
         return opa, opb
 
     def logical_and(self, other, context=None):
-        """Applies an 'and' operation between self and other's digits."""
+        """Applies an 'and' operation between self and other's digits.
+
+        Both self and other must be logical numbers.
+        """
         if context is None:
             context = getcontext()
 
@@ -3319,14 +3360,20 @@ class Decimal(object):
         return _dec_from_triple(0, result.lstrip('0') or '0', 0)
 
     def logical_invert(self, context=None):
-        """Invert all its digits."""
+        """Invert all its digits.
+
+        The self must be logical number.
+        """
         if context is None:
             context = getcontext()
         return self.logical_xor(_dec_from_triple(0,'1'*context.prec,0),
                                 context)
 
     def logical_or(self, other, context=None):
-        """Applies an 'or' operation between self and other's digits."""
+        """Applies an 'or' operation between self and other's digits.
+
+        Both self and other must be logical numbers.
+        """
         if context is None:
             context = getcontext()
 
@@ -3343,7 +3390,10 @@ class Decimal(object):
         return _dec_from_triple(0, result.lstrip('0') or '0', 0)
 
     def logical_xor(self, other, context=None):
-        """Applies an 'xor' operation between self and other's digits."""
+        """Applies an 'xor' operation between self and other's digits.
+
+        Both self and other must be logical numbers.
+        """
         if context is None:
             context = getcontext()
 
@@ -6058,7 +6108,7 @@ _parser = re.compile(r"""        # A numeric string consists of:
         (?P<diag>\d*)            # with (possibly empty) diagnostic info.
     )
 #    \s*
-    \Z
+    \z
 """, re.VERBOSE | re.IGNORECASE).match
 
 _all_zeros = re.compile('0*$').match
@@ -6082,11 +6132,15 @@ _parse_format_specifier_regex = re.compile(r"""\A
 (?P<no_neg_0>z)?
 (?P<alt>\#)?
 (?P<zeropad>0)?
-(?P<minimumwidth>(?!0)\d+)?
-(?P<thousands_sep>,)?
-(?:\.(?P<precision>0|(?!0)\d+))?
+(?P<minimumwidth>\d+)?
+(?P<thousands_sep>[,_])?
+(?:\.
+    (?=[\d,_])  # lookahead for digit or separator
+    (?P<precision>\d+)?
+    (?P<frac_separators>[,_])?
+)?
 (?P<type>[eEfFgGn%])?
-\Z
+\z
 """, re.VERBOSE|re.DOTALL)
 
 del re
@@ -6177,6 +6231,9 @@ def _parse_format_specifier(format_spec, _localeconv=None):
         format_dict['grouping'] = [3, 0]
         format_dict['decimal_point'] = '.'
 
+    if format_dict['frac_separators'] is None:
+        format_dict['frac_separators'] = ''
+
     return format_dict
 
 def _format_align(sign, body, spec):
@@ -6296,6 +6353,11 @@ def _format_number(is_negative, intpart, fracpart, exp, spec):
 
     sign = _format_sign(is_negative, spec)
 
+    frac_sep = spec['frac_separators']
+    if fracpart and frac_sep:
+        fracpart = frac_sep.join(fracpart[pos:pos + 3]
+                                 for pos in range(0, len(fracpart), 3))
+
     if fracpart or spec['alt']:
         fracpart = spec['decimal_point'] + fracpart
 

Lib/decimal.py

@@ -100,8 +100,8 @@ NaN
 
 try:
     from _decimal import *
-    from _decimal import __version__
-    from _decimal import __libmpdec_version__
+    from _decimal import __version__  # noqa: F401
+    from _decimal import __libmpdec_version__  # noqa: F401
 except ImportError:
     import _pydecimal
     import sys

Lib/test/test_decimal.py

@@ -45,6 +45,7 @@ from test.support import warnings_helper
 import random
 import inspect
 import threading
+import contextvars
 
 
 if sys.platform == 'darwin':
@@ -753,7 +754,7 @@ class ExplicitConstructionTest:
         for v in [-2**63-1, -2**63, -2**31-1, -2**31, 0,
                    2**31-1, 2**31, 2**63-1, 2**63]:
             d = nc.create_decimal(v)
-            self.assertTrue(isinstance(d, Decimal))
+            self.assertIsInstance(d, Decimal)
             self.assertEqual(int(d), v)
 
         nc.prec = 3
@@ -813,6 +814,29 @@ class ExplicitConstructionTest:
             x = random.expovariate(0.01) * (random.random() * 2.0 - 1.0)
             self.assertEqual(x, float(nc.create_decimal(x))) # roundtrip
 
+    def test_from_number(self, cls=None):
+        Decimal = self.decimal.Decimal
+        if cls is None:
+            cls = Decimal
+
+        def check(arg, expected):
+            d = cls.from_number(arg)
+            self.assertIs(type(d), cls)
+            self.assertEqual(d, expected)
+
+        check(314, Decimal(314))
+        check(3.14, Decimal.from_float(3.14))
+        check(Decimal('3.14'), Decimal('3.14'))
+        self.assertRaises(TypeError, cls.from_number, 3+4j)
+        self.assertRaises(TypeError, cls.from_number, '314')
+        self.assertRaises(TypeError, cls.from_number, (0, (3, 1, 4), 0))
+        self.assertRaises(TypeError, cls.from_number, object())
+
+    def test_from_number_subclass(self, cls=None):
+        class DecimalSubclass(self.decimal.Decimal):
+            pass
+        self.test_from_number(DecimalSubclass)
+
     def test_unicode_digits(self):
         Decimal = self.decimal.Decimal
 
@@ -830,9 +854,8 @@ class CExplicitConstructionTest(ExplicitConstructionTest, unittest.TestCase):
 class PyExplicitConstructionTest(ExplicitConstructionTest, unittest.TestCase):
     decimal = P
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
-    def test_unicode_digits(self): # TODO(RUSTPYTHON): Remove this test when it pass
+    @unittest.expectedFailure  # TODO: RUSTPYTHON
+    def test_unicode_digits(self):
         return super().test_unicode_digits()
 
 class ImplicitConstructionTest:
@@ -963,6 +986,7 @@ class FormatTest:
             ('.0f', '0e-2', '0'),
             ('.0f', '3.14159265', '3'),
             ('.1f', '3.14159265', '3.1'),
+            ('.01f', '3.14159265', '3.1'), # leading zero in precision
             ('.4f', '3.14159265', '3.1416'),
             ('.6f', '3.14159265', '3.141593'),
             ('.7f', '3.14159265', '3.1415926'), # round-half-even!
@@ -1048,6 +1072,7 @@ class FormatTest:
             ('8,', '123456', ' 123,456'),
             ('08,', '123456', '0,123,456'), # special case: extra 0 needed
             ('+08,', '123456', '+123,456'), # but not if there's a sign
+            ('008,', '123456', '0,123,456'), # leading zero in width
             (' 08,', '123456', ' 123,456'),
             ('08,', '-123456', '-123,456'),
             ('+09,', '123456', '+0,123,456'),
@@ -1064,6 +1089,20 @@ class FormatTest:
             (',%', '123.456789', '12,345.6789%'),
             (',e', '123456', '1.23456e+5'),
             (',E', '123456', '1.23456E+5'),
+            # ... with '_' instead
+            ('_', '1234567', '1_234_567'),
+            ('07_', '1234.56', '1_234.56'),
+            ('_', '1.23456789', '1.23456789'),
+            ('_%', '123.456789', '12_345.6789%'),
+            # and now for something completely different...
+            ('.,', '1.23456789', '1.234,567,89'),
+            ('._', '1.23456789', '1.234_567_89'),
+            ('.6_f', '12345.23456789', '12345.234_568'),
+            (',._%', '123.456789', '12,345.678_9%'),
+            (',._e', '123456', '1.234_56e+5'),
+            (',.4_e', '123456', '1.234_6e+5'),
+            (',.3_e', '123456', '1.235e+5'),
+            (',._E', '123456', '1.234_56E+5'),
 
             # negative zero: default behavior
             ('.1f', '-0', '-0.0'),
@@ -1137,6 +1176,10 @@ class FormatTest:
         # bytes format argument
         self.assertRaises(TypeError, Decimal(1).__format__, b'-020')
 
+        # precision or fractional part separator should follow after dot
+        self.assertRaises(ValueError, format, Decimal(1), '.f')
+        self.assertRaises(ValueError, format, Decimal(1), '._6f')
+
     def test_negative_zero_format_directed_rounding(self):
         with self.decimal.localcontext() as ctx:
             ctx.rounding = ROUND_CEILING
@@ -1708,8 +1751,13 @@ class ThreadingTest:
         self.finish1 = threading.Event()
         self.finish2 = threading.Event()
 
-        th1 = threading.Thread(target=thfunc1, args=(self,))
-        th2 = threading.Thread(target=thfunc2, args=(self,))
+        # This test wants to start threads with an empty context, no matter
+        # the setting of sys.flags.thread_inherit_context.  We pass the
+        # 'context' argument explicitly with an empty context instance.
+        th1 = threading.Thread(target=thfunc1, args=(self,),
+                               context=contextvars.Context())
+        th2 = threading.Thread(target=thfunc2, args=(self,),
+                               context=contextvars.Context())
 
         th1.start()
         th2.start()
@@ -2573,8 +2621,8 @@ class PythonAPItests:
     def test_abc(self):
         Decimal = self.decimal.Decimal
 
-        self.assertTrue(issubclass(Decimal, numbers.Number))
-        self.assertFalse(issubclass(Decimal, numbers.Real))
+        self.assertIsSubclass(Decimal, numbers.Number)
+        self.assertNotIsSubclass(Decimal, numbers.Real)
         self.assertIsInstance(Decimal(0), numbers.Number)
         self.assertNotIsInstance(Decimal(0), numbers.Real)
 
@@ -2673,7 +2721,7 @@ class PythonAPItests:
             def __init__(self, _):
                 self.x = 'y'
 
-        self.assertTrue(issubclass(MyDecimal, Decimal))
+        self.assertIsSubclass(MyDecimal, Decimal)
 
         r = MyDecimal.from_float(0.1)
         self.assertEqual(type(r), MyDecimal)
@@ -2891,31 +2939,31 @@ class PythonAPItests:
         Rounded = decimal.Rounded
         Clamped = decimal.Clamped
 
-        self.assertTrue(issubclass(DecimalException, ArithmeticError))
+        self.assertIsSubclass(DecimalException, ArithmeticError)
 
-        self.assertTrue(issubclass(InvalidOperation, DecimalException))
-        self.assertTrue(issubclass(FloatOperation, DecimalException))
-        self.assertTrue(issubclass(FloatOperation, TypeError))
-        self.assertTrue(issubclass(DivisionByZero, DecimalException))
-        self.assertTrue(issubclass(DivisionByZero, ZeroDivisionError))
-        self.assertTrue(issubclass(Overflow, Rounded))
-        self.assertTrue(issubclass(Overflow, Inexact))
-        self.assertTrue(issubclass(Overflow, DecimalException))
-        self.assertTrue(issubclass(Underflow, Inexact))
-        self.assertTrue(issubclass(Underflow, Rounded))
-        self.assertTrue(issubclass(Underflow, Subnormal))
-        self.assertTrue(issubclass(Underflow, DecimalException))
+        self.assertIsSubclass(InvalidOperation, DecimalException)
+        self.assertIsSubclass(FloatOperation, DecimalException)
+        self.assertIsSubclass(FloatOperation, TypeError)
+        self.assertIsSubclass(DivisionByZero, DecimalException)
+        self.assertIsSubclass(DivisionByZero, ZeroDivisionError)
+        self.assertIsSubclass(Overflow, Rounded)
+        self.assertIsSubclass(Overflow, Inexact)
+        self.assertIsSubclass(Overflow, DecimalException)
+        self.assertIsSubclass(Underflow, Inexact)
+        self.assertIsSubclass(Underflow, Rounded)
+        self.assertIsSubclass(Underflow, Subnormal)
+        self.assertIsSubclass(Underflow, DecimalException)
 
-        self.assertTrue(issubclass(Subnormal, DecimalException))
-        self.assertTrue(issubclass(Inexact, DecimalException))
-        self.assertTrue(issubclass(Rounded, DecimalException))
-        self.assertTrue(issubclass(Clamped, DecimalException))
+        self.assertIsSubclass(Subnormal, DecimalException)
+        self.assertIsSubclass(Inexact, DecimalException)
+        self.assertIsSubclass(Rounded, DecimalException)
+        self.assertIsSubclass(Clamped, DecimalException)
 
-        self.assertTrue(issubclass(decimal.ConversionSyntax, InvalidOperation))
-        self.assertTrue(issubclass(decimal.DivisionImpossible, InvalidOperation))
-        self.assertTrue(issubclass(decimal.DivisionUndefined, InvalidOperation))
-        self.assertTrue(issubclass(decimal.DivisionUndefined, ZeroDivisionError))
-        self.assertTrue(issubclass(decimal.InvalidContext, InvalidOperation))
+        self.assertIsSubclass(decimal.ConversionSyntax, InvalidOperation)
+        self.assertIsSubclass(decimal.DivisionImpossible, InvalidOperation)
+        self.assertIsSubclass(decimal.DivisionUndefined, InvalidOperation)
+        self.assertIsSubclass(decimal.DivisionUndefined, ZeroDivisionError)
+        self.assertIsSubclass(decimal.InvalidContext, InvalidOperation)
 
 @requires_cdecimal
 class CPythonAPItests(PythonAPItests, unittest.TestCase):
@@ -2923,7 +2971,6 @@ class CPythonAPItests(PythonAPItests, unittest.TestCase):
 class PyPythonAPItests(PythonAPItests, unittest.TestCase):
     decimal = P
 
-
 class ContextAPItests:
 
     def test_none_args(self):
@@ -4371,6 +4418,51 @@ class CContextSubclassing(ContextSubclassing, unittest.TestCase):
 class PyContextSubclassing(ContextSubclassing, unittest.TestCase):
     decimal = P
 
+class IEEEContexts:
+
+    def test_ieee_context(self):
+        # issue 8786: Add support for IEEE 754 contexts to decimal module.
+        IEEEContext = self.decimal.IEEEContext
+
+        def assert_rest(self, context):
+            self.assertEqual(context.clamp, 1)
+            assert_signals(self, context, 'traps', [])
+            assert_signals(self, context, 'flags', [])
+
+        c = IEEEContext(32)
+        self.assertEqual(c.prec, 7)
+        self.assertEqual(c.Emax, 96)
+        self.assertEqual(c.Emin, -95)
+        assert_rest(self, c)
+
+        c = IEEEContext(64)
+        self.assertEqual(c.prec, 16)
+        self.assertEqual(c.Emax, 384)
+        self.assertEqual(c.Emin, -383)
+        assert_rest(self, c)
+
+        c = IEEEContext(128)
+        self.assertEqual(c.prec, 34)
+        self.assertEqual(c.Emax, 6144)
+        self.assertEqual(c.Emin, -6143)
+        assert_rest(self, c)
+
+        # Invalid values
+        self.assertRaises(ValueError, IEEEContext, -1)
+        self.assertRaises(ValueError, IEEEContext, 123)
+        self.assertRaises(ValueError, IEEEContext, 1024)
+
+    def test_constants(self):
+        # IEEEContext
+        IEEE_CONTEXT_MAX_BITS = self.decimal.IEEE_CONTEXT_MAX_BITS
+        self.assertIn(IEEE_CONTEXT_MAX_BITS, {256, 512})
+
+@requires_cdecimal
+class CIEEEContexts(IEEEContexts, unittest.TestCase):
+    decimal = C
+class PyIEEEContexts(IEEEContexts, unittest.TestCase):
+    decimal = P
+
 @skip_if_extra_functionality
 @requires_cdecimal
 class CheckAttributes(unittest.TestCase):
@@ -4382,6 +4474,7 @@ class CheckAttributes(unittest.TestCase):
         self.assertEqual(C.MAX_EMAX, P.MAX_EMAX)
         self.assertEqual(C.MIN_EMIN, P.MIN_EMIN)
         self.assertEqual(C.MIN_ETINY, P.MIN_ETINY)
+        self.assertEqual(C.IEEE_CONTEXT_MAX_BITS, P.IEEE_CONTEXT_MAX_BITS)
 
         self.assertTrue(C.HAVE_THREADS is True or C.HAVE_THREADS is False)
         self.assertTrue(P.HAVE_THREADS is True or P.HAVE_THREADS is False)
@@ -4465,12 +4558,10 @@ class Coverage:
             self.assertIs(Decimal("NaN").fma(7, 1).is_nan(), True)
             # three arg power
             self.assertEqual(pow(Decimal(10), 2, 7), 2)
+            self.assertEqual(pow(10, Decimal(2), 7), 2)
             if self.decimal == C:
-                self.assertEqual(pow(10, Decimal(2), 7), 2)
                 self.assertEqual(pow(10, 2, Decimal(7)), 2)
             else:
-                # XXX: Three-arg power doesn't use __rpow__.
-                self.assertRaises(TypeError, pow, 10, Decimal(2), 7)
                 # XXX: There is no special method to dispatch on the
                 # third arg of three-arg power.
                 self.assertRaises(TypeError, pow, 10, 2, Decimal(7))
@@ -4684,10 +4775,6 @@ class PyCoverage(Coverage, unittest.TestCase):
         sys.set_int_max_str_digits(self._previous_int_limit)
         super().tearDown()
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
-    def test_implicit_context(self): # TODO(RUSTPYTHON): Remove this test when it pass
-        return super().test_implicit_context()
 
 class PyFunctionality(unittest.TestCase):
     """Extra functionality in decimal.py"""
@@ -4872,42 +4959,6 @@ class PyWhitebox(unittest.TestCase):
 class CFunctionality(unittest.TestCase):
     """Extra functionality in _decimal"""
 
-    @requires_extra_functionality
-    def test_c_ieee_context(self):
-        # issue 8786: Add support for IEEE 754 contexts to decimal module.
-        IEEEContext = C.IEEEContext
-        DECIMAL32 = C.DECIMAL32
-        DECIMAL64 = C.DECIMAL64
-        DECIMAL128 = C.DECIMAL128
-
-        def assert_rest(self, context):
-            self.assertEqual(context.clamp, 1)
-            assert_signals(self, context, 'traps', [])
-            assert_signals(self, context, 'flags', [])
-
-        c = IEEEContext(DECIMAL32)
-        self.assertEqual(c.prec, 7)
-        self.assertEqual(c.Emax, 96)
-        self.assertEqual(c.Emin, -95)
-        assert_rest(self, c)
-
-        c = IEEEContext(DECIMAL64)
-        self.assertEqual(c.prec, 16)
-        self.assertEqual(c.Emax, 384)
-        self.assertEqual(c.Emin, -383)
-        assert_rest(self, c)
-
-        c = IEEEContext(DECIMAL128)
-        self.assertEqual(c.prec, 34)
-        self.assertEqual(c.Emax, 6144)
-        self.assertEqual(c.Emin, -6143)
-        assert_rest(self, c)
-
-        # Invalid values
-        self.assertRaises(OverflowError, IEEEContext, 2**63)
-        self.assertRaises(ValueError, IEEEContext, -1)
-        self.assertRaises(ValueError, IEEEContext, 1024)
-
     @requires_extra_functionality
     def test_c_context(self):
         Context = C.Context
@@ -4928,12 +4979,6 @@ class CFunctionality(unittest.TestCase):
             C.DecSubnormal, C.DecUnderflow
         )
 
-        # IEEEContext
-        self.assertEqual(C.DECIMAL32, 32)
-        self.assertEqual(C.DECIMAL64, 64)
-        self.assertEqual(C.DECIMAL128, 128)
-        self.assertEqual(C.IEEE_CONTEXT_MAX_BITS, 512)
-
         # Conditions
         for i, v in enumerate(cond):
             self.assertEqual(v, 1<<i)