symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_decimal.py
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_decimal.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,1527 @@
+# Copyright (c) 2004 Python Software Foundation.
+# All rights reserved.
+
+# Written by Eric Price <eprice at tjhsst.edu>
+#    and Facundo Batista <facundo at taniquetil.com.ar>
+#    and Raymond Hettinger <python at rcn.com>
+#    and Aahz (aahz at pobox.com)
+#    and Tim Peters
+
+"""
+These are the test cases for the Decimal module.
+
+There are two groups of tests, Arithmetic and Behaviour. The former test
+the Decimal arithmetic using the tests provided by Mike Cowlishaw. The latter
+test the pythonic behaviour according to PEP 327.
+
+Cowlishaw's tests can be downloaded from:
+
+   www2.hursley.ibm.com/decimal/dectest.zip
+
+This test module can be called from command line with one parameter (Arithmetic
+or Behaviour) to test each part, or without parameter to test both parts. If
+you're working through IDLE, you can import this test module and call test_main()
+with the corresponding argument.
+"""
+
+import glob
+import math
+import os, sys
+import pickle, copy
+import unittest
+from decimal import *
+from test.test_support import (TestSkipped, run_unittest, run_doctest,
+                               is_resource_enabled)
+import random
+try:
+    import threading
+except ImportError:
+    threading = None
+
+# Useful Test Constant
+Signals = getcontext().flags.keys()
+
+# Tests are built around these assumed context defaults.
+# test_main() restores the original context.
+def init():
+    global ORIGINAL_CONTEXT
+    ORIGINAL_CONTEXT = getcontext().copy()
+    DefaultTestContext = Context(
+        prec = 9,
+        rounding = ROUND_HALF_EVEN,
+        traps = dict.fromkeys(Signals, 0)
+        )
+    setcontext(DefaultTestContext)
+
+TESTDATADIR = 'decimaltestdata'
+if __name__ == '__main__':
+    file = sys.argv[0]
+else:
+    file = __file__
+testdir = os.path.dirname(file) or os.curdir
+directory = testdir + os.sep + TESTDATADIR + os.sep
+
+skip_expected = not os.path.isdir(directory)
+
+# Make sure it actually raises errors when not expected and caught in flags
+# Slower, since it runs some things several times.
+EXTENDEDERRORTEST = False
+
+#Map the test cases' error names to the actual errors
+ErrorNames = {'clamped' : Clamped,
+              'conversion_syntax' : InvalidOperation,
+              'division_by_zero' : DivisionByZero,
+              'division_impossible' : InvalidOperation,
+              'division_undefined' : InvalidOperation,
+              'inexact' : Inexact,
+              'invalid_context' : InvalidOperation,
+              'invalid_operation' : InvalidOperation,
+              'overflow' : Overflow,
+              'rounded' : Rounded,
+              'subnormal' : Subnormal,
+              'underflow' : Underflow}
+
+
+def Nonfunction(*args):
+    """Doesn't do anything."""
+    return None
+
+RoundingDict = {'ceiling' : ROUND_CEILING, #Maps test-case names to roundings.
+                'down' : ROUND_DOWN,
+                'floor' : ROUND_FLOOR,
+                'half_down' : ROUND_HALF_DOWN,
+                'half_even' : ROUND_HALF_EVEN,
+                'half_up' : ROUND_HALF_UP,
+                'up' : ROUND_UP,
+                '05up' : ROUND_05UP}
+
+# Name adapter to be able to change the Decimal and Context
+# interface without changing the test files from Cowlishaw
+nameAdapter = {'and':'logical_and',
+               'apply':'_apply',
+               'class':'number_class',
+               'comparesig':'compare_signal',
+               'comparetotal':'compare_total',
+               'comparetotmag':'compare_total_mag',
+               'copy':'copy_decimal',
+               'copyabs':'copy_abs',
+               'copynegate':'copy_negate',
+               'copysign':'copy_sign',
+               'divideint':'divide_int',
+               'invert':'logical_invert',
+               'iscanonical':'is_canonical',
+               'isfinite':'is_finite',
+               'isinfinite':'is_infinite',
+               'isnan':'is_nan',
+               'isnormal':'is_normal',
+               'isqnan':'is_qnan',
+               'issigned':'is_signed',
+               'issnan':'is_snan',
+               'issubnormal':'is_subnormal',
+               'iszero':'is_zero',
+               'maxmag':'max_mag',
+               'minmag':'min_mag',
+               'nextminus':'next_minus',
+               'nextplus':'next_plus',
+               'nexttoward':'next_toward',
+               'or':'logical_or',
+               'reduce':'normalize',
+               'remaindernear':'remainder_near',
+               'samequantum':'same_quantum',
+               'squareroot':'sqrt',
+               'toeng':'to_eng_string',
+               'tointegral':'to_integral_value',
+               'tointegralx':'to_integral_exact',
+               'tosci':'to_sci_string',
+               'xor':'logical_xor',
+              }
+
+# The following functions return True/False rather than a Decimal instance
+
+LOGICAL_FUNCTIONS = (
+    'is_canonical',
+    'is_finite',
+    'is_infinite',
+    'is_nan',
+    'is_normal',
+    'is_qnan',
+    'is_signed',
+    'is_snan',
+    'is_subnormal',
+    'is_zero',
+    'same_quantum',
+    )
+
+# For some operations (currently exp, ln, log10, power), the decNumber
+# reference implementation imposes additional restrictions on the
+# context and operands.  These restrictions are not part of the
+# specification; however, the effect of these restrictions does show
+# up in some of the testcases.  We skip testcases that violate these
+# restrictions, since Decimal behaves differently from decNumber for
+# these testcases so these testcases would otherwise fail.
+
+decNumberRestricted = ('power', 'ln', 'log10', 'exp')
+DEC_MAX_MATH = 999999
+def outside_decNumber_bounds(v, context):
+    if (context.prec > DEC_MAX_MATH or
+        context.Emax > DEC_MAX_MATH or
+        -context.Emin > DEC_MAX_MATH):
+        return True
+    if not v._is_special and v and (
+        len(v._int) > DEC_MAX_MATH or
+        v.adjusted() > DEC_MAX_MATH or
+        v.adjusted() < 1-2*DEC_MAX_MATH):
+        return True
+    return False
+
+class DecimalTest(unittest.TestCase):
+    """Class which tests the Decimal class against the test cases.
+
+    Changed for unittest.
+    """
+    def setUp(self):
+        self.context = Context()
+        self.ignore_list = ['#']
+        # Basically, a # means return NaN InvalidOperation.
+        # Different from a sNaN in trim
+
+        self.ChangeDict = {'precision' : self.change_precision,
+                      'rounding' : self.change_rounding_method,
+                      'maxexponent' : self.change_max_exponent,
+                      'minexponent' : self.change_min_exponent,
+                      'clamp' : self.change_clamp}
+
+    def eval_file(self, file):
+        global skip_expected
+        if skip_expected:
+            raise TestSkipped
+            return
+        for line in open(file).xreadlines():
+            line = line.replace('\r\n', '').replace('\n', '')
+            #print line
+            try:
+                t = self.eval_line(line)
+            except DecimalException, exception:
+                #Exception raised where there shoudn't have been one.
+                self.fail('Exception "'+exception.__class__.__name__ + '" raised on line '+line)
+
+        return
+
+    def eval_line(self, s):
+        if s.find(' -> ') >= 0 and s[:2] != '--' and not s.startswith('  --'):
+            s = (s.split('->')[0] + '->' +
+                 s.split('->')[1].split('--')[0]).strip()
+        else:
+            s = s.split('--')[0].strip()
+
+        for ignore in self.ignore_list:
+            if s.find(ignore) >= 0:
+                #print s.split()[0], 'NotImplemented--', ignore
+                return
+        if not s:
+            return
+        elif ':' in s:
+            return self.eval_directive(s)
+        else:
+            return self.eval_equation(s)
+
+    def eval_directive(self, s):
+        funct, value = map(lambda x: x.strip().lower(), s.split(':'))
+        if funct == 'rounding':
+            value = RoundingDict[value]
+        else:
+            try:
+                value = int(value)
+            except ValueError:
+                pass
+
+        funct = self.ChangeDict.get(funct, Nonfunction)
+        funct(value)
+
+    def eval_equation(self, s):
+        #global DEFAULT_PRECISION
+        #print DEFAULT_PRECISION
+
+        if not TEST_ALL and random.random() < 0.90:
+            return
+
+        try:
+            Sides = s.split('->')
+            L = Sides[0].strip().split()
+            id = L[0]
+            if DEBUG:
+                print "Test ", id,
+            funct = L[1].lower()
+            valstemp = L[2:]
+            L = Sides[1].strip().split()
+            ans = L[0]
+            exceptions = L[1:]
+        except (TypeError, AttributeError, IndexError):
+            raise InvalidOperation
+        def FixQuotes(val):
+            val = val.replace("''", 'SingleQuote').replace('""', 'DoubleQuote')
+            val = val.replace("'", '').replace('"', '')
+            val = val.replace('SingleQuote', "'").replace('DoubleQuote', '"')
+            return val
+        fname = nameAdapter.get(funct, funct)
+        if fname == 'rescale':
+            return
+        funct = getattr(self.context, fname)
+        vals = []
+        conglomerate = ''
+        quote = 0
+        theirexceptions = [ErrorNames[x.lower()] for x in exceptions]
+
+        for exception in Signals:
+            self.context.traps[exception] = 1 #Catch these bugs...
+        for exception in theirexceptions:
+            self.context.traps[exception] = 0
+        for i, val in enumerate(valstemp):
+            if val.count("'") % 2 == 1:
+                quote = 1 - quote
+            if quote:
+                conglomerate = conglomerate + ' ' + val
+                continue
+            else:
+                val = conglomerate + val
+                conglomerate = ''
+            v = FixQuotes(val)
+            if fname in ('to_sci_string', 'to_eng_string'):
+                if EXTENDEDERRORTEST:
+                    for error in theirexceptions:
+                        self.context.traps[error] = 1
+                        try:
+                            funct(self.context.create_decimal(v))
+                        except error:
+                            pass
+                        except Signals, e:
+                            self.fail("Raised %s in %s when %s disabled" % \
+                                      (e, s, error))
+                        else:
+                            self.fail("Did not raise %s in %s" % (error, s))
+                        self.context.traps[error] = 0
+                v = self.context.create_decimal(v)
+            else:
+                v = Decimal(v, self.context)
+            vals.append(v)
+
+        ans = FixQuotes(ans)
+
+        # skip tests that are related to bounds imposed in the decNumber
+        # reference implementation
+        if fname in decNumberRestricted:
+            if fname == 'power':
+                if not (vals[1]._isinteger() and
+                        -1999999997 <= vals[1] <= 999999999):
+                    if outside_decNumber_bounds(vals[0], self.context) or \
+                            outside_decNumber_bounds(vals[1], self.context):
+                        #print "Skipping test %s" % s
+                        return
+            else:
+                if outside_decNumber_bounds(vals[0], self.context):
+                    #print "Skipping test %s" % s
+                    return
+
+
+        if EXTENDEDERRORTEST and fname not in ('to_sci_string', 'to_eng_string'):
+            for error in theirexceptions:
+                self.context.traps[error] = 1
+                try:
+                    funct(*vals)
+                except error:
+                    pass
+                except Signals, e:
+                    self.fail("Raised %s in %s when %s disabled" % \
+                              (e, s, error))
+                else:
+                    self.fail("Did not raise %s in %s" % (error, s))
+                self.context.traps[error] = 0
+        if DEBUG:
+            print "--", self.context
+        try:
+            result = str(funct(*vals))
+            if fname in LOGICAL_FUNCTIONS:
+                result = str(int(eval(result))) # 'True', 'False' -> '1', '0'
+        except Signals, error:
+            self.fail("Raised %s in %s" % (error, s))
+        except: #Catch any error long enough to state the test case.
+            print "ERROR:", s
+            raise
+
+        myexceptions = self.getexceptions()
+        self.context.clear_flags()
+
+        myexceptions.sort()
+        theirexceptions.sort()
+
+        self.assertEqual(result, ans,
+                         'Incorrect answer for ' + s + ' -- got ' + result)
+        self.assertEqual(myexceptions, theirexceptions,
+              'Incorrect flags set in ' + s + ' -- got ' + str(myexceptions))
+        return
+
+    def getexceptions(self):
+        return [e for e in Signals if self.context.flags[e]]
+
+    def change_precision(self, prec):
+        self.context.prec = prec
+    def change_rounding_method(self, rounding):
+        self.context.rounding = rounding
+    def change_min_exponent(self, exp):
+        self.context.Emin = exp
+    def change_max_exponent(self, exp):
+        self.context.Emax = exp
+    def change_clamp(self, clamp):
+        self.context._clamp = clamp
+
+
+
+# The following classes test the behaviour of Decimal according to PEP 327
+
+class DecimalExplicitConstructionTest(unittest.TestCase):
+    '''Unit tests for Explicit Construction cases of Decimal.'''
+
+    def test_explicit_empty(self):
+        self.assertEqual(Decimal(), Decimal("0"))
+
+    def test_explicit_from_None(self):
+        self.assertRaises(TypeError, Decimal, None)
+
+    def test_explicit_from_int(self):
+
+        #positive
+        d = Decimal(45)
+        self.assertEqual(str(d), '45')
+
+        #very large positive
+        d = Decimal(500000123)
+        self.assertEqual(str(d), '500000123')
+
+        #negative
+        d = Decimal(-45)
+        self.assertEqual(str(d), '-45')
+
+        #zero
+        d = Decimal(0)
+        self.assertEqual(str(d), '0')
+
+    def test_explicit_from_string(self):
+
+        #empty
+        self.assertEqual(str(Decimal('')), 'NaN')
+
+        #int
+        self.assertEqual(str(Decimal('45')), '45')
+
+        #float
+        self.assertEqual(str(Decimal('45.34')), '45.34')
+
+        #engineer notation
+        self.assertEqual(str(Decimal('45e2')), '4.5E+3')
+
+        #just not a number
+        self.assertEqual(str(Decimal('ugly')), 'NaN')
+
+        #leading and trailing whitespace permitted
+        self.assertEqual(str(Decimal('1.3E4 \n')), '1.3E+4')
+        self.assertEqual(str(Decimal('  -7.89')), '-7.89')
+
+        #unicode strings should be permitted
+        self.assertEqual(str(Decimal(u'0E-017')), '0E-17')
+        self.assertEqual(str(Decimal(u'45')), '45')
+        self.assertEqual(str(Decimal(u'-Inf')), '-Infinity')
+        self.assertEqual(str(Decimal(u'NaN123')), 'NaN123')
+
+        #but alternate unicode digits should not
+        self.assertEqual(str(Decimal(u'\uff11')), 'NaN')
+
+    def test_explicit_from_tuples(self):
+
+        #zero
+        d = Decimal( (0, (0,), 0) )
+        self.assertEqual(str(d), '0')
+
+        #int
+        d = Decimal( (1, (4, 5), 0) )
+        self.assertEqual(str(d), '-45')
+
+        #float
+        d = Decimal( (0, (4, 5, 3, 4), -2) )
+        self.assertEqual(str(d), '45.34')
+
+        #weird
+        d = Decimal( (1, (4, 3, 4, 9, 1, 3, 5, 3, 4), -25) )
+        self.assertEqual(str(d), '-4.34913534E-17')
+
+        #wrong number of items
+        self.assertRaises(ValueError, Decimal, (1, (4, 3, 4, 9, 1)) )
+
+        #bad sign
+        self.assertRaises(ValueError, Decimal, (8, (4, 3, 4, 9, 1), 2) )
+        self.assertRaises(ValueError, Decimal, (0., (4, 3, 4, 9, 1), 2) )
+        self.assertRaises(ValueError, Decimal, (Decimal(1), (4, 3, 4, 9, 1), 2))
+
+        #bad exp
+        self.assertRaises(ValueError, Decimal, (1, (4, 3, 4, 9, 1), 'wrong!') )
+        self.assertRaises(ValueError, Decimal, (1, (4, 3, 4, 9, 1), 0.) )
+        self.assertRaises(ValueError, Decimal, (1, (4, 3, 4, 9, 1), '1') )
+
+        #bad coefficients
+        self.assertRaises(ValueError, Decimal, (1, (4, 3, 4, None, 1), 2) )
+        self.assertRaises(ValueError, Decimal, (1, (4, -3, 4, 9, 1), 2) )
+        self.assertRaises(ValueError, Decimal, (1, (4, 10, 4, 9, 1), 2) )
+        self.assertRaises(ValueError, Decimal, (1, (4, 3, 4, 'a', 1), 2) )
+
+    def test_explicit_from_Decimal(self):
+
+        #positive
+        d = Decimal(45)
+        e = Decimal(d)
+        self.assertEqual(str(e), '45')
+        self.assertNotEqual(id(d), id(e))
+
+        #very large positive
+        d = Decimal(500000123)
+        e = Decimal(d)
+        self.assertEqual(str(e), '500000123')
+        self.assertNotEqual(id(d), id(e))
+
+        #negative
+        d = Decimal(-45)
+        e = Decimal(d)
+        self.assertEqual(str(e), '-45')
+        self.assertNotEqual(id(d), id(e))
+
+        #zero
+        d = Decimal(0)
+        e = Decimal(d)
+        self.assertEqual(str(e), '0')
+        self.assertNotEqual(id(d), id(e))
+
+    def test_explicit_context_create_decimal(self):
+
+        nc = copy.copy(getcontext())
+        nc.prec = 3
+
+        # empty
+        d = Decimal()
+        self.assertEqual(str(d), '0')
+        d = nc.create_decimal()
+        self.assertEqual(str(d), '0')
+
+        # from None
+        self.assertRaises(TypeError, nc.create_decimal, None)
+
+        # from int
+        d = nc.create_decimal(456)
+        self.failUnless(isinstance(d, Decimal))
+        self.assertEqual(nc.create_decimal(45678),
+                         nc.create_decimal('457E+2'))
+
+        # from string
+        d = Decimal('456789')
+        self.assertEqual(str(d), '456789')
+        d = nc.create_decimal('456789')
+        self.assertEqual(str(d), '4.57E+5')
+        # leading and trailing whitespace should result in a NaN;
+        # spaces are already checked in Cowlishaw's test-suite, so
+        # here we just check that a trailing newline results in a NaN
+        self.assertEqual(str(nc.create_decimal('3.14\n')), 'NaN')
+
+        # from tuples
+        d = Decimal( (1, (4, 3, 4, 9, 1, 3, 5, 3, 4), -25) )
+        self.assertEqual(str(d), '-4.34913534E-17')
+        d = nc.create_decimal( (1, (4, 3, 4, 9, 1, 3, 5, 3, 4), -25) )
+        self.assertEqual(str(d), '-4.35E-17')
+
+        # from Decimal
+        prevdec = Decimal(500000123)
+        d = Decimal(prevdec)
+        self.assertEqual(str(d), '500000123')
+        d = nc.create_decimal(prevdec)
+        self.assertEqual(str(d), '5.00E+8')
+
+
+class DecimalImplicitConstructionTest(unittest.TestCase):
+    '''Unit tests for Implicit Construction cases of Decimal.'''
+
+    def test_implicit_from_None(self):
+        self.assertRaises(TypeError, eval, 'Decimal(5) + None', globals())
+
+    def test_implicit_from_int(self):
+        #normal
+        self.assertEqual(str(Decimal(5) + 45), '50')
+        #exceeding precision
+        self.assertEqual(Decimal(5) + 123456789000, Decimal(123456789000))
+
+    def test_implicit_from_string(self):
+        self.assertRaises(TypeError, eval, 'Decimal(5) + "3"', globals())
+
+    def test_implicit_from_float(self):
+        self.assertRaises(TypeError, eval, 'Decimal(5) + 2.2', globals())
+
+    def test_implicit_from_Decimal(self):
+        self.assertEqual(Decimal(5) + Decimal(45), Decimal(50))
+
+    def test_rop(self):
+        # Allow other classes to be trained to interact with Decimals
+        class E:
+            def __divmod__(self, other):
+                return 'divmod ' + str(other)
+            def __rdivmod__(self, other):
+                return str(other) + ' rdivmod'
+            def __lt__(self, other):
+                return 'lt ' + str(other)
+            def __gt__(self, other):
+                return 'gt ' + str(other)
+            def __le__(self, other):
+                return 'le ' + str(other)
+            def __ge__(self, other):
+                return 'ge ' + str(other)
+            def __eq__(self, other):
+                return 'eq ' + str(other)
+            def __ne__(self, other):
+                return 'ne ' + str(other)
+
+        self.assertEqual(divmod(E(), Decimal(10)), 'divmod 10')
+        self.assertEqual(divmod(Decimal(10), E()), '10 rdivmod')
+        self.assertEqual(eval('Decimal(10) < E()'), 'gt 10')
+        self.assertEqual(eval('Decimal(10) > E()'), 'lt 10')
+        self.assertEqual(eval('Decimal(10) <= E()'), 'ge 10')
+        self.assertEqual(eval('Decimal(10) >= E()'), 'le 10')
+        self.assertEqual(eval('Decimal(10) == E()'), 'eq 10')
+        self.assertEqual(eval('Decimal(10) != E()'), 'ne 10')
+
+        # insert operator methods and then exercise them
+        oplist = [
+            ('+', '__add__', '__radd__'),
+            ('-', '__sub__', '__rsub__'),
+            ('*', '__mul__', '__rmul__'),
+            ('%', '__mod__', '__rmod__'),
+            ('//', '__floordiv__', '__rfloordiv__'),
+            ('**', '__pow__', '__rpow__')
+        ]
+        if 1/2 == 0:
+            # testing with classic division, so add __div__
+            oplist.append(('/', '__div__', '__rdiv__'))
+        else:
+            # testing with -Qnew, so add __truediv__
+            oplist.append(('/', '__truediv__', '__rtruediv__'))
+
+        for sym, lop, rop in oplist:
+            setattr(E, lop, lambda self, other: 'str' + lop + str(other))
+            setattr(E, rop, lambda self, other: str(other) + rop + 'str')
+            self.assertEqual(eval('E()' + sym + 'Decimal(10)'),
+                             'str' + lop + '10')
+            self.assertEqual(eval('Decimal(10)' + sym + 'E()'),
+                             '10' + rop + 'str')
+
+class DecimalFormatTest(unittest.TestCase):
+    '''Unit tests for the format function.'''
+    def test_formatting(self):
+        # triples giving a format, a Decimal, and the expected result
+        test_values = [
+            ('e', '0E-15', '0e-15'),
+            ('e', '2.3E-15', '2.3e-15'),
+            ('e', '2.30E+2', '2.30e+2'), # preserve significant zeros
+            ('e', '2.30000E-15', '2.30000e-15'),
+            ('e', '1.23456789123456789e40', '1.23456789123456789e+40'),
+            ('e', '1.5', '1.5e+0'),
+            ('e', '0.15', '1.5e-1'),
+            ('e', '0.015', '1.5e-2'),
+            ('e', '0.0000000000015', '1.5e-12'),
+            ('e', '15.0', '1.50e+1'),
+            ('e', '-15', '-1.5e+1'),
+            ('e', '0', '0e+0'),
+            ('e', '0E1', '0e+1'),
+            ('e', '0.0', '0e-1'),
+            ('e', '0.00', '0e-2'),
+            ('.6e', '0E-15', '0.000000e-9'),
+            ('.6e', '0', '0.000000e+6'),
+            ('.6e', '9.999999', '9.999999e+0'),
+            ('.6e', '9.9999999', '1.000000e+1'),
+            ('.6e', '-1.23e5', '-1.230000e+5'),
+            ('.6e', '1.23456789e-3', '1.234568e-3'),
+            ('f', '0', '0'),
+            ('f', '0.0', '0.0'),
+            ('f', '0E-2', '0.00'),
+            ('f', '0.00E-8', '0.0000000000'),
+            ('f', '0E1', '0'), # loses exponent information
+            ('f', '3.2E1', '32'),
+            ('f', '3.2E2', '320'),
+            ('f', '3.20E2', '320'),
+            ('f', '3.200E2', '320.0'),
+            ('f', '3.2E-6', '0.0000032'),
+            ('.6f', '0E-15', '0.000000'), # all zeros treated equally
+            ('.6f', '0E1', '0.000000'),
+            ('.6f', '0', '0.000000'),
+            ('.0f', '0', '0'), # no decimal point
+            ('.0f', '0e-2', '0'),
+            ('.0f', '3.14159265', '3'),
+            ('.1f', '3.14159265', '3.1'),
+            ('.4f', '3.14159265', '3.1416'),
+            ('.6f', '3.14159265', '3.141593'),
+            ('.7f', '3.14159265', '3.1415926'), # round-half-even!
+            ('.8f', '3.14159265', '3.14159265'),
+            ('.9f', '3.14159265', '3.141592650'),
+
+            ('g', '0', '0'),
+            ('g', '0.0', '0.0'),
+            ('g', '0E1', '0e+1'),
+            ('G', '0E1', '0E+1'),
+            ('g', '0E-5', '0.00000'),
+            ('g', '0E-6', '0.000000'),
+            ('g', '0E-7', '0e-7'),
+            ('g', '-0E2', '-0e+2'),
+            ('.0g', '3.14159265', '3'),  # 0 sig fig -> 1 sig fig
+            ('.1g', '3.14159265', '3'),
+            ('.2g', '3.14159265', '3.1'),
+            ('.5g', '3.14159265', '3.1416'),
+            ('.7g', '3.14159265', '3.141593'),
+            ('.8g', '3.14159265', '3.1415926'), # round-half-even!
+            ('.9g', '3.14159265', '3.14159265'),
+            ('.10g', '3.14159265', '3.14159265'), # don't pad
+
+            ('%', '0E1', '0%'),
+            ('%', '0E0', '0%'),
+            ('%', '0E-1', '0%'),
+            ('%', '0E-2', '0%'),
+            ('%', '0E-3', '0.0%'),
+            ('%', '0E-4', '0.00%'),
+
+            ('.3%', '0', '0.000%'), # all zeros treated equally
+            ('.3%', '0E10', '0.000%'),
+            ('.3%', '0E-10', '0.000%'),
+            ('.3%', '2.34', '234.000%'),
+            ('.3%', '1.234567', '123.457%'),
+            ('.0%', '1.23', '123%'),
+
+            ('e', 'NaN', 'NaN'),
+            ('f', '-NaN123', '-NaN123'),
+            ('+g', 'NaN456', '+NaN456'),
+            ('.3e', 'Inf', 'Infinity'),
+            ('.16f', '-Inf', '-Infinity'),
+            ('.0g', '-sNaN', '-sNaN'),
+
+            ('', '1.00', '1.00'),
+            ]
+        for fmt, d, result in test_values:
+            self.assertEqual(format(Decimal(d), fmt), result)
+
+class DecimalArithmeticOperatorsTest(unittest.TestCase):
+    '''Unit tests for all arithmetic operators, binary and unary.'''
+
+    def test_addition(self):
+
+        d1 = Decimal('-11.1')
+        d2 = Decimal('22.2')
+
+        #two Decimals
+        self.assertEqual(d1+d2, Decimal('11.1'))
+        self.assertEqual(d2+d1, Decimal('11.1'))
+
+        #with other type, left
+        c = d1 + 5
+        self.assertEqual(c, Decimal('-6.1'))
+        self.assertEqual(type(c), type(d1))
+
+        #with other type, right
+        c = 5 + d1
+        self.assertEqual(c, Decimal('-6.1'))
+        self.assertEqual(type(c), type(d1))
+
+        #inline with decimal
+        d1 += d2
+        self.assertEqual(d1, Decimal('11.1'))
+
+        #inline with other type
+        d1 += 5
+        self.assertEqual(d1, Decimal('16.1'))
+
+    def test_subtraction(self):
+
+        d1 = Decimal('-11.1')
+        d2 = Decimal('22.2')
+
+        #two Decimals
+        self.assertEqual(d1-d2, Decimal('-33.3'))
+        self.assertEqual(d2-d1, Decimal('33.3'))
+
+        #with other type, left
+        c = d1 - 5
+        self.assertEqual(c, Decimal('-16.1'))
+        self.assertEqual(type(c), type(d1))
+
+        #with other type, right
+        c = 5 - d1
+        self.assertEqual(c, Decimal('16.1'))
+        self.assertEqual(type(c), type(d1))
+
+        #inline with decimal
+        d1 -= d2
+        self.assertEqual(d1, Decimal('-33.3'))
+
+        #inline with other type
+        d1 -= 5
+        self.assertEqual(d1, Decimal('-38.3'))
+
+    def test_multiplication(self):
+
+        d1 = Decimal('-5')
+        d2 = Decimal('3')
+
+        #two Decimals
+        self.assertEqual(d1*d2, Decimal('-15'))
+        self.assertEqual(d2*d1, Decimal('-15'))
+
+        #with other type, left
+        c = d1 * 5
+        self.assertEqual(c, Decimal('-25'))
+        self.assertEqual(type(c), type(d1))
+
+        #with other type, right
+        c = 5 * d1
+        self.assertEqual(c, Decimal('-25'))
+        self.assertEqual(type(c), type(d1))
+
+        #inline with decimal
+        d1 *= d2
+        self.assertEqual(d1, Decimal('-15'))
+
+        #inline with other type
+        d1 *= 5
+        self.assertEqual(d1, Decimal('-75'))
+
+    def test_division(self):
+
+        d1 = Decimal('-5')
+        d2 = Decimal('2')
+
+        #two Decimals
+        self.assertEqual(d1/d2, Decimal('-2.5'))
+        self.assertEqual(d2/d1, Decimal('-0.4'))
+
+        #with other type, left
+        c = d1 / 4
+        self.assertEqual(c, Decimal('-1.25'))
+        self.assertEqual(type(c), type(d1))
+
+        #with other type, right
+        c = 4 / d1
+        self.assertEqual(c, Decimal('-0.8'))
+        self.assertEqual(type(c), type(d1))
+
+        #inline with decimal
+        d1 /= d2
+        self.assertEqual(d1, Decimal('-2.5'))
+
+        #inline with other type
+        d1 /= 4
+        self.assertEqual(d1, Decimal('-0.625'))
+
+    def test_floor_division(self):
+
+        d1 = Decimal('5')
+        d2 = Decimal('2')
+
+        #two Decimals
+        self.assertEqual(d1//d2, Decimal('2'))
+        self.assertEqual(d2//d1, Decimal('0'))
+
+        #with other type, left
+        c = d1 // 4
+        self.assertEqual(c, Decimal('1'))
+        self.assertEqual(type(c), type(d1))
+
+        #with other type, right
+        c = 7 // d1
+        self.assertEqual(c, Decimal('1'))
+        self.assertEqual(type(c), type(d1))
+
+        #inline with decimal
+        d1 //= d2
+        self.assertEqual(d1, Decimal('2'))
+
+        #inline with other type
+        d1 //= 2
+        self.assertEqual(d1, Decimal('1'))
+
+    def test_powering(self):
+
+        d1 = Decimal('5')
+        d2 = Decimal('2')
+
+        #two Decimals
+        self.assertEqual(d1**d2, Decimal('25'))
+        self.assertEqual(d2**d1, Decimal('32'))
+
+        #with other type, left
+        c = d1 ** 4
+        self.assertEqual(c, Decimal('625'))
+        self.assertEqual(type(c), type(d1))
+
+        #with other type, right
+        c = 7 ** d1
+        self.assertEqual(c, Decimal('16807'))
+        self.assertEqual(type(c), type(d1))
+
+        #inline with decimal
+        d1 **= d2
+        self.assertEqual(d1, Decimal('25'))
+
+        #inline with other type
+        d1 **= 4
+        self.assertEqual(d1, Decimal('390625'))
+
+    def test_module(self):
+
+        d1 = Decimal('5')
+        d2 = Decimal('2')
+
+        #two Decimals
+        self.assertEqual(d1%d2, Decimal('1'))
+        self.assertEqual(d2%d1, Decimal('2'))
+
+        #with other type, left
+        c = d1 % 4
+        self.assertEqual(c, Decimal('1'))
+        self.assertEqual(type(c), type(d1))
+
+        #with other type, right
+        c = 7 % d1
+        self.assertEqual(c, Decimal('2'))
+        self.assertEqual(type(c), type(d1))
+
+        #inline with decimal
+        d1 %= d2
+        self.assertEqual(d1, Decimal('1'))
+
+        #inline with other type
+        d1 %= 4
+        self.assertEqual(d1, Decimal('1'))
+
+    def test_floor_div_module(self):
+
+        d1 = Decimal('5')
+        d2 = Decimal('2')
+
+        #two Decimals
+        (p, q) = divmod(d1, d2)
+        self.assertEqual(p, Decimal('2'))
+        self.assertEqual(q, Decimal('1'))
+        self.assertEqual(type(p), type(d1))
+        self.assertEqual(type(q), type(d1))
+
+        #with other type, left
+        (p, q) = divmod(d1, 4)
+        self.assertEqual(p, Decimal('1'))
+        self.assertEqual(q, Decimal('1'))
+        self.assertEqual(type(p), type(d1))
+        self.assertEqual(type(q), type(d1))
+
+        #with other type, right
+        (p, q) = divmod(7, d1)
+        self.assertEqual(p, Decimal('1'))
+        self.assertEqual(q, Decimal('2'))
+        self.assertEqual(type(p), type(d1))
+        self.assertEqual(type(q), type(d1))
+
+    def test_unary_operators(self):
+        self.assertEqual(+Decimal(45), Decimal(+45))           #  +
+        self.assertEqual(-Decimal(45), Decimal(-45))           #  -
+        self.assertEqual(abs(Decimal(45)), abs(Decimal(-45)))  # abs
+
+    def test_nan_comparisons(self):
+        n = Decimal('NaN')
+        s = Decimal('sNaN')
+        i = Decimal('Inf')
+        f = Decimal('2')
+        for x, y in [(n, n), (n, i), (i, n), (n, f), (f, n),
+                     (s, n), (n, s), (s, i), (i, s), (s, f), (f, s), (s, s)]:
+            self.assert_(x != y)
+            self.assert_(not (x == y))
+            self.assert_(not (x < y))
+            self.assert_(not (x <= y))
+            self.assert_(not (x > y))
+            self.assert_(not (x >= y))
+
+# The following are two functions used to test threading in the next class
+
+def thfunc1(cls):
+    d1 = Decimal(1)
+    d3 = Decimal(3)
+    test1 = d1/d3
+    cls.synchro.wait()
+    test2 = d1/d3
+    cls.finish1.set()
+
+    cls.assertEqual(test1, Decimal('0.3333333333333333333333333333'))
+    cls.assertEqual(test2, Decimal('0.3333333333333333333333333333'))
+    return
+
+def thfunc2(cls):
+    d1 = Decimal(1)
+    d3 = Decimal(3)
+    test1 = d1/d3
+    thiscontext = getcontext()
+    thiscontext.prec = 18
+    test2 = d1/d3
+    cls.synchro.set()
+    cls.finish2.set()
+
+    cls.assertEqual(test1, Decimal('0.3333333333333333333333333333'))
+    cls.assertEqual(test2, Decimal('0.333333333333333333'))
+    return
+
+
+class DecimalUseOfContextTest(unittest.TestCase):
+    '''Unit tests for Use of Context cases in Decimal.'''
+
+    try:
+        import threading
+    except ImportError:
+        threading = None
+
+    # Take care executing this test from IDLE, there's an issue in threading
+    # that hangs IDLE and I couldn't find it
+
+    def test_threading(self):
+        #Test the "threading isolation" of a Context.
+
+        self.synchro = threading.Event()
+        self.finish1 = threading.Event()
+        self.finish2 = threading.Event()
+
+        th1 = threading.Thread(target=thfunc1, args=(self,))
+        th2 = threading.Thread(target=thfunc2, args=(self,))
+
+        th1.start()
+        th2.start()
+
+        self.finish1.wait()
+        self.finish2.wait()
+        return
+
+    if threading is None:
+        del test_threading
+
+
+class DecimalUsabilityTest(unittest.TestCase):
+    '''Unit tests for Usability cases of Decimal.'''
+
+    def test_comparison_operators(self):
+
+        da = Decimal('23.42')
+        db = Decimal('23.42')
+        dc = Decimal('45')
+
+        #two Decimals
+        self.failUnless(dc > da)
+        self.failUnless(dc >= da)
+        self.failUnless(da < dc)
+        self.failUnless(da <= dc)
+        self.failUnless(da == db)
+        self.failUnless(da != dc)
+        self.failUnless(da <= db)
+        self.failUnless(da >= db)
+        self.assertEqual(cmp(dc,da), 1)
+        self.assertEqual(cmp(da,dc), -1)
+        self.assertEqual(cmp(da,db), 0)
+
+        #a Decimal and an int
+        self.failUnless(dc > 23)
+        self.failUnless(23 < dc)
+        self.failUnless(dc == 45)
+        self.assertEqual(cmp(dc,23), 1)
+        self.assertEqual(cmp(23,dc), -1)
+        self.assertEqual(cmp(dc,45), 0)
+
+        #a Decimal and uncomparable
+        self.assertNotEqual(da, 'ugly')
+        self.assertNotEqual(da, 32.7)
+        self.assertNotEqual(da, object())
+        self.assertNotEqual(da, object)
+
+        # sortable
+        a = map(Decimal, xrange(100))
+        b =  a[:]
+        random.shuffle(a)
+        a.sort()
+        self.assertEqual(a, b)
+
+        # with None
+        self.assertFalse(Decimal(1) < None)
+        self.assertTrue(Decimal(1) > None)
+
+    def test_copy_and_deepcopy_methods(self):
+        d = Decimal('43.24')
+        c = copy.copy(d)
+        self.assertEqual(id(c), id(d))
+        dc = copy.deepcopy(d)
+        self.assertEqual(id(dc), id(d))
+
+    def test_hash_method(self):
+        #just that it's hashable
+        hash(Decimal(23))
+
+        test_values = [Decimal(sign*(2**m + n))
+                       for m in [0, 14, 15, 16, 17, 30, 31,
+                                 32, 33, 62, 63, 64, 65, 66]
+                       for n in range(-10, 10)
+                       for sign in [-1, 1]]
+        test_values.extend([
+                Decimal("-0"), # zeros
+                Decimal("0.00"),
+                Decimal("-0.000"),
+                Decimal("0E10"),
+                Decimal("-0E12"),
+                Decimal("10.0"), # negative exponent
+                Decimal("-23.00000"),
+                Decimal("1230E100"), # positive exponent
+                Decimal("-4.5678E50"),
+                # a value for which hash(n) != hash(n % (2**64-1))
+                # in Python pre-2.6
+                Decimal(2**64 + 2**32 - 1),
+                # selection of values which fail with the old (before
+                # version 2.6) long.__hash__
+                Decimal("1.634E100"),
+                Decimal("90.697E100"),
+                Decimal("188.83E100"),
+                Decimal("1652.9E100"),
+                Decimal("56531E100"),
+                ])
+
+        # check that hash(d) == hash(int(d)) for integral values
+        for value in test_values:
+            self.assertEqual(hash(value), hash(int(value)))
+
+        #the same hash that to an int
+        self.assertEqual(hash(Decimal(23)), hash(23))
+        self.assertRaises(TypeError, hash, Decimal('NaN'))
+        self.assert_(hash(Decimal('Inf')))
+        self.assert_(hash(Decimal('-Inf')))
+
+        # check that the value of the hash doesn't depend on the
+        # current context (issue #1757)
+        c = getcontext()
+        old_precision = c.prec
+        x = Decimal("123456789.1")
+
+        c.prec = 6
+        h1 = hash(x)
+        c.prec = 10
+        h2 = hash(x)
+        c.prec = 16
+        h3 = hash(x)
+
+        self.assertEqual(h1, h2)
+        self.assertEqual(h1, h3)
+        c.prec = old_precision
+
+    def test_min_and_max_methods(self):
+
+        d1 = Decimal('15.32')
+        d2 = Decimal('28.5')
+        l1 = 15
+        l2 = 28
+
+        #between Decimals
+        self.failUnless(min(d1,d2) is d1)
+        self.failUnless(min(d2,d1) is d1)
+        self.failUnless(max(d1,d2) is d2)
+        self.failUnless(max(d2,d1) is d2)
+
+        #between Decimal and long
+        self.failUnless(min(d1,l2) is d1)
+        self.failUnless(min(l2,d1) is d1)
+        self.failUnless(max(l1,d2) is d2)
+        self.failUnless(max(d2,l1) is d2)
+
+    def test_as_nonzero(self):
+        #as false
+        self.failIf(Decimal(0))
+        #as true
+        self.failUnless(Decimal('0.372'))
+
+    def test_tostring_methods(self):
+        #Test str and repr methods.
+
+        d = Decimal('15.32')
+        self.assertEqual(str(d), '15.32')               # str
+        self.assertEqual(repr(d), "Decimal('15.32')")   # repr
+
+        # result type of string methods should be str, not unicode
+        unicode_inputs = [u'123.4', u'0.5E2', u'Infinity', u'sNaN',
+                          u'-0.0E100', u'-NaN001', u'-Inf']
+
+        for u in unicode_inputs:
+            d = Decimal(u)
+            self.assertEqual(type(str(d)), str)
+            self.assertEqual(type(repr(d)), str)
+            self.assertEqual(type(d.to_eng_string()), str)
+
+    def test_tonum_methods(self):
+        #Test float, int and long methods.
+
+        d1 = Decimal('66')
+        d2 = Decimal('15.32')
+
+        #int
+        self.assertEqual(int(d1), 66)
+        self.assertEqual(int(d2), 15)
+
+        #long
+        self.assertEqual(long(d1), 66)
+        self.assertEqual(long(d2), 15)
+
+        #float
+        self.assertEqual(float(d1), 66)
+        self.assertEqual(float(d2), 15.32)
+
+    def test_eval_round_trip(self):
+
+        #with zero
+        d = Decimal( (0, (0,), 0) )
+        self.assertEqual(d, eval(repr(d)))
+
+        #int
+        d = Decimal( (1, (4, 5), 0) )
+        self.assertEqual(d, eval(repr(d)))
+
+        #float
+        d = Decimal( (0, (4, 5, 3, 4), -2) )
+        self.assertEqual(d, eval(repr(d)))
+
+        #weird
+        d = Decimal( (1, (4, 3, 4, 9, 1, 3, 5, 3, 4), -25) )
+        self.assertEqual(d, eval(repr(d)))
+
+    def test_as_tuple(self):
+
+        #with zero
+        d = Decimal(0)
+        self.assertEqual(d.as_tuple(), (0, (0,), 0) )
+
+        #int
+        d = Decimal(-45)
+        self.assertEqual(d.as_tuple(), (1, (4, 5), 0) )
+
+        #complicated string
+        d = Decimal("-4.34913534E-17")
+        self.assertEqual(d.as_tuple(), (1, (4, 3, 4, 9, 1, 3, 5, 3, 4), -25) )
+
+        #inf
+        d = Decimal("Infinity")
+        self.assertEqual(d.as_tuple(), (0, (0,), 'F') )
+
+        #leading zeros in coefficient should be stripped
+        d = Decimal( (0, (0, 0, 4, 0, 5, 3, 4), -2) )
+        self.assertEqual(d.as_tuple(), (0, (4, 0, 5, 3, 4), -2) )
+        d = Decimal( (1, (0, 0, 0), 37) )
+        self.assertEqual(d.as_tuple(), (1, (0,), 37))
+        d = Decimal( (1, (), 37) )
+        self.assertEqual(d.as_tuple(), (1, (0,), 37))
+
+        #leading zeros in NaN diagnostic info should be stripped
+        d = Decimal( (0, (0, 0, 4, 0, 5, 3, 4), 'n') )
+        self.assertEqual(d.as_tuple(), (0, (4, 0, 5, 3, 4), 'n') )
+        d = Decimal( (1, (0, 0, 0), 'N') )
+        self.assertEqual(d.as_tuple(), (1, (), 'N') )
+        d = Decimal( (1, (), 'n') )
+        self.assertEqual(d.as_tuple(), (1, (), 'n') )
+
+        #coefficient in infinity should be ignored
+        d = Decimal( (0, (4, 5, 3, 4), 'F') )
+        self.assertEqual(d.as_tuple(), (0, (0,), 'F'))
+        d = Decimal( (1, (0, 2, 7, 1), 'F') )
+        self.assertEqual(d.as_tuple(), (1, (0,), 'F'))
+
+    def test_immutability_operations(self):
+        # Do operations and check that it didn't change change internal objects.
+
+        d1 = Decimal('-25e55')
+        b1 = Decimal('-25e55')
+        d2 = Decimal('33e+33')
+        b2 = Decimal('33e+33')
+
+        def checkSameDec(operation, useOther=False):
+            if useOther:
+                eval("d1." + operation + "(d2)")
+                self.assertEqual(d1._sign, b1._sign)
+                self.assertEqual(d1._int, b1._int)
+                self.assertEqual(d1._exp, b1._exp)
+                self.assertEqual(d2._sign, b2._sign)
+                self.assertEqual(d2._int, b2._int)
+                self.assertEqual(d2._exp, b2._exp)
+            else:
+                eval("d1." + operation + "()")
+                self.assertEqual(d1._sign, b1._sign)
+                self.assertEqual(d1._int, b1._int)
+                self.assertEqual(d1._exp, b1._exp)
+            return
+
+        Decimal(d1)
+        self.assertEqual(d1._sign, b1._sign)
+        self.assertEqual(d1._int, b1._int)
+        self.assertEqual(d1._exp, b1._exp)
+
+        checkSameDec("__abs__")
+        checkSameDec("__add__", True)
+        checkSameDec("__div__", True)
+        checkSameDec("__divmod__", True)
+        checkSameDec("__eq__", True)
+        checkSameDec("__ne__", True)
+        checkSameDec("__le__", True)
+        checkSameDec("__lt__", True)
+        checkSameDec("__ge__", True)
+        checkSameDec("__gt__", True)
+        checkSameDec("__float__")
+        checkSameDec("__floordiv__", True)
+        checkSameDec("__hash__")
+        checkSameDec("__int__")
+        checkSameDec("__trunc__")
+        checkSameDec("__long__")
+        checkSameDec("__mod__", True)
+        checkSameDec("__mul__", True)
+        checkSameDec("__neg__")
+        checkSameDec("__nonzero__")
+        checkSameDec("__pos__")
+        checkSameDec("__pow__", True)
+        checkSameDec("__radd__", True)
+        checkSameDec("__rdiv__", True)
+        checkSameDec("__rdivmod__", True)
+        checkSameDec("__repr__")
+        checkSameDec("__rfloordiv__", True)
+        checkSameDec("__rmod__", True)
+        checkSameDec("__rmul__", True)
+        checkSameDec("__rpow__", True)
+        checkSameDec("__rsub__", True)
+        checkSameDec("__str__")
+        checkSameDec("__sub__", True)
+        checkSameDec("__truediv__", True)
+        checkSameDec("adjusted")
+        checkSameDec("as_tuple")
+        checkSameDec("compare", True)
+        checkSameDec("max", True)
+        checkSameDec("min", True)
+        checkSameDec("normalize")
+        checkSameDec("quantize", True)
+        checkSameDec("remainder_near", True)
+        checkSameDec("same_quantum", True)
+        checkSameDec("sqrt")
+        checkSameDec("to_eng_string")
+        checkSameDec("to_integral")
+
+    def test_subclassing(self):
+        # Different behaviours when subclassing Decimal
+
+        class MyDecimal(Decimal):
+            pass
+
+        d1 = MyDecimal(1)
+        d2 = MyDecimal(2)
+        d = d1 + d2
+        self.assertTrue(type(d) is Decimal)
+
+        d = d1.max(d2)
+        self.assertTrue(type(d) is Decimal)
+
+    def test_implicit_context(self):
+        # Check results when context given implicitly.  (Issue 2478)
+        c = getcontext()
+        self.assertEqual(str(Decimal(0).sqrt()),
+                         str(c.sqrt(Decimal(0))))
+
+
+class DecimalPythonAPItests(unittest.TestCase):
+
+    def test_pickle(self):
+        d = Decimal('-3.141590000')
+        p = pickle.dumps(d)
+        e = pickle.loads(p)
+        self.assertEqual(d, e)
+
+    def test_int(self):
+        for x in range(-250, 250):
+            s = '%0.2f' % (x / 100.0)
+            # should work the same as for floats
+            self.assertEqual(int(Decimal(s)), int(float(s)))
+            # should work the same as to_integral in the ROUND_DOWN mode
+            d = Decimal(s)
+            r = d.to_integral(ROUND_DOWN)
+            self.assertEqual(Decimal(int(d)), r)
+
+    def test_trunc(self):
+        for x in range(-250, 250):
+            s = '%0.2f' % (x / 100.0)
+            # should work the same as for floats
+            self.assertEqual(int(Decimal(s)), int(float(s)))
+            # should work the same as to_integral in the ROUND_DOWN mode
+            d = Decimal(s)
+            r = d.to_integral(ROUND_DOWN)
+            self.assertEqual(Decimal(math.trunc(d)), r)
+
+class ContextAPItests(unittest.TestCase):
+
+    def test_pickle(self):
+        c = Context()
+        e = pickle.loads(pickle.dumps(c))
+        for k in vars(c):
+            v1 = vars(c)[k]
+            v2 = vars(e)[k]
+            self.assertEqual(v1, v2)
+
+    def test_equality_with_other_types(self):
+        self.assert_(Decimal(10) in ['a', 1.0, Decimal(10), (1,2), {}])
+        self.assert_(Decimal(10) not in ['a', 1.0, (1,2), {}])
+
+    def test_copy(self):
+        # All copies should be deep
+        c = Context()
+        d = c.copy()
+        self.assertNotEqual(id(c), id(d))
+        self.assertNotEqual(id(c.flags), id(d.flags))
+        self.assertNotEqual(id(c.traps), id(d.traps))
+
+class WithStatementTest(unittest.TestCase):
+    # Can't do these as docstrings until Python 2.6
+    # as doctest can't handle __future__ statements
+
+    def test_localcontext(self):
+        # Use a copy of the current context in the block
+        orig_ctx = getcontext()
+        with localcontext() as enter_ctx:
+            set_ctx = getcontext()
+        final_ctx = getcontext()
+        self.assert_(orig_ctx is final_ctx, 'did not restore context correctly')
+        self.assert_(orig_ctx is not set_ctx, 'did not copy the context')
+        self.assert_(set_ctx is enter_ctx, '__enter__ returned wrong context')
+
+    def test_localcontextarg(self):
+        # Use a copy of the supplied context in the block
+        orig_ctx = getcontext()
+        new_ctx = Context(prec=42)
+        with localcontext(new_ctx) as enter_ctx:
+            set_ctx = getcontext()
+        final_ctx = getcontext()
+        self.assert_(orig_ctx is final_ctx, 'did not restore context correctly')
+        self.assert_(set_ctx.prec == new_ctx.prec, 'did not set correct context')
+        self.assert_(new_ctx is not set_ctx, 'did not copy the context')
+        self.assert_(set_ctx is enter_ctx, '__enter__ returned wrong context')
+
+class ContextFlags(unittest.TestCase):
+    def test_flags_irrelevant(self):
+        # check that the result (numeric result + flags raised) of an
+        # arithmetic operation doesn't depend on the current flags
+
+        context = Context(prec=9, Emin = -999999999, Emax = 999999999,
+                    rounding=ROUND_HALF_EVEN, traps=[], flags=[])
+
+        # operations that raise various flags, in the form (function, arglist)
+        operations = [
+            (context._apply, [Decimal("100E-1000000009")]),
+            (context.sqrt, [Decimal(2)]),
+            (context.add, [Decimal("1.23456789"), Decimal("9.87654321")]),
+            (context.multiply, [Decimal("1.23456789"), Decimal("9.87654321")]),
+            (context.subtract, [Decimal("1.23456789"), Decimal("9.87654321")]),
+            ]
+
+        # try various flags individually, then a whole lot at once
+        flagsets = [[Inexact], [Rounded], [Underflow], [Clamped], [Subnormal],
+                    [Inexact, Rounded, Underflow, Clamped, Subnormal]]
+
+        for fn, args in operations:
+            # find answer and flags raised using a clean context
+            context.clear_flags()
+            ans = fn(*args)
+            flags = [k for k, v in context.flags.items() if v]
+
+            for extra_flags in flagsets:
+                # set flags, before calling operation
+                context.clear_flags()
+                for flag in extra_flags:
+                    context._raise_error(flag)
+                new_ans = fn(*args)
+
+                # flags that we expect to be set after the operation
+                expected_flags = list(flags)
+                for flag in extra_flags:
+                    if flag not in expected_flags:
+                        expected_flags.append(flag)
+                expected_flags.sort()
+
+                # flags we actually got
+                new_flags = [k for k,v in context.flags.items() if v]
+                new_flags.sort()
+
+                self.assertEqual(ans, new_ans,
+                                 "operation produces different answers depending on flags set: " +
+                                 "expected %s, got %s." % (ans, new_ans))
+                self.assertEqual(new_flags, expected_flags,
+                                  "operation raises different flags depending on flags set: " +
+                                  "expected %s, got %s" % (expected_flags, new_flags))
+
+def test_main(arith=False, verbose=None, todo_tests=None, debug=None):
+    """ Execute the tests.
+
+    Runs all arithmetic tests if arith is True or if the "decimal" resource
+    is enabled in regrtest.py
+    """
+
+    init()
+    global TEST_ALL, DEBUG
+    TEST_ALL = arith or is_resource_enabled('decimal')
+    DEBUG = debug
+
+    if todo_tests is None:
+        test_classes = [
+            DecimalExplicitConstructionTest,
+            DecimalImplicitConstructionTest,
+            DecimalArithmeticOperatorsTest,
+            DecimalFormatTest,
+            DecimalUseOfContextTest,
+            DecimalUsabilityTest,
+            DecimalPythonAPItests,
+            ContextAPItests,
+            DecimalTest,
+            WithStatementTest,
+            ContextFlags
+        ]
+    else:
+        test_classes = [DecimalTest]
+
+    # Dynamically build custom test definition for each file in the test
+    # directory and add the definitions to the DecimalTest class.  This
+    # procedure insures that new files do not get skipped.
+    for filename in os.listdir(directory):
+        if '.decTest' not in filename or filename.startswith("."):
+            continue
+        head, tail = filename.split('.')
+        if todo_tests is not None and head not in todo_tests:
+            continue
+        tester = lambda self, f=filename: self.eval_file(directory + f)
+        setattr(DecimalTest, 'test_' + head, tester)
+        del filename, head, tail, tester
+
+
+    try:
+        run_unittest(*test_classes)
+        if todo_tests is None:
+            import decimal as DecimalModule
+            run_doctest(DecimalModule, verbose)
+    finally:
+        setcontext(ORIGINAL_CONTEXT)
+
+if __name__ == '__main__':
+    import optparse
+    p = optparse.OptionParser("test_decimal.py [--debug] [{--skip | test1 [test2 [...]]}]")
+    p.add_option('--debug', '-d', action='store_true', help='shows the test number and context before each test')
+    p.add_option('--skip',  '-s', action='store_true', help='skip over 90% of the arithmetic tests')
+    (opt, args) = p.parse_args()
+
+    if opt.skip:
+        test_main(arith=False, verbose=True)
+    elif args:
+        test_main(arith=True, verbose=True, todo_tests=args, debug=opt.debug)
+    else:
+        test_main(arith=True, verbose=True)