mirror of
https://github.com/python/cpython.git
synced 2025-10-30 21:21:22 +00:00
45169fbc80
__init__ to __new__ to enforce immutability, and remove "rational." from repr and the parens from str.
342 lines
14 KiB
Python
342 lines
14 KiB
Python
"""Tests for Lib/rational.py."""
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from decimal import Decimal
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from test.test_support import run_unittest, verbose
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import math
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import operator
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import rational
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import unittest
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R = rational.Rational
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def _components(r):
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return (r.numerator, r.denominator)
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class RationalTest(unittest.TestCase):
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def assertTypedEquals(self, expected, actual):
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"""Asserts that both the types and values are the same."""
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self.assertEquals(type(expected), type(actual))
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self.assertEquals(expected, actual)
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def assertRaisesMessage(self, exc_type, message,
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callable, *args, **kwargs):
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"""Asserts that callable(*args, **kwargs) raises exc_type(message)."""
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try:
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callable(*args, **kwargs)
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except exc_type, e:
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self.assertEquals(message, str(e))
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else:
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self.fail("%s not raised" % exc_type.__name__)
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def testInit(self):
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self.assertEquals((0, 1), _components(R()))
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self.assertEquals((7, 1), _components(R(7)))
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self.assertEquals((7, 3), _components(R(R(7, 3))))
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self.assertEquals((-1, 1), _components(R(-1, 1)))
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self.assertEquals((-1, 1), _components(R(1, -1)))
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self.assertEquals((1, 1), _components(R(-2, -2)))
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self.assertEquals((1, 2), _components(R(5, 10)))
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self.assertEquals((7, 15), _components(R(7, 15)))
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self.assertEquals((10**23, 1), _components(R(10**23)))
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self.assertRaisesMessage(ZeroDivisionError, "Rational(12, 0)",
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R, 12, 0)
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self.assertRaises(TypeError, R, 1.5)
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self.assertRaises(TypeError, R, 1.5 + 3j)
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self.assertRaises(TypeError, R, R(1, 2), 3)
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self.assertRaises(TypeError, R, "3/2", 3)
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def testFromString(self):
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self.assertEquals((5, 1), _components(R("5")))
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self.assertEquals((3, 2), _components(R("3/2")))
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self.assertEquals((3, 2), _components(R(" \n +3/2")))
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self.assertEquals((-3, 2), _components(R("-3/2 ")))
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self.assertEquals((3, 2), _components(R(" 03/02 \n ")))
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self.assertEquals((3, 2), _components(R(u" 03/02 \n ")))
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self.assertRaisesMessage(
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ZeroDivisionError, "Rational(3, 0)",
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R, "3/0")
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self.assertRaisesMessage(
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ValueError, "Invalid literal for Rational: 3/",
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R, "3/")
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self.assertRaisesMessage(
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ValueError, "Invalid literal for Rational: 3 /2",
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R, "3 /2")
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self.assertRaisesMessage(
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# Denominators don't need a sign.
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ValueError, "Invalid literal for Rational: 3/+2",
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R, "3/+2")
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self.assertRaisesMessage(
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# Imitate float's parsing.
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ValueError, "Invalid literal for Rational: + 3/2",
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R, "+ 3/2")
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self.assertRaisesMessage(
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# Only parse fractions, not decimals.
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ValueError, "Invalid literal for Rational: 3.2",
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R, "3.2")
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def testImmutable(self):
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r = R(7, 3)
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r.__init__(2, 15)
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self.assertEquals((7, 3), _components(r))
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def testFromFloat(self):
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self.assertRaisesMessage(
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TypeError, "Rational.from_float() only takes floats, not 3 (int)",
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R.from_float, 3)
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self.assertEquals((0, 1), _components(R.from_float(-0.0)))
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self.assertEquals((10, 1), _components(R.from_float(10.0)))
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self.assertEquals((-5, 2), _components(R.from_float(-2.5)))
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self.assertEquals((99999999999999991611392, 1),
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_components(R.from_float(1e23)))
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self.assertEquals(float(10**23), float(R.from_float(1e23)))
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self.assertEquals((3602879701896397, 1125899906842624),
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_components(R.from_float(3.2)))
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self.assertEquals(3.2, float(R.from_float(3.2)))
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inf = 1e1000
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nan = inf - inf
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self.assertRaisesMessage(
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TypeError, "Cannot convert inf to Rational.",
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R.from_float, inf)
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self.assertRaisesMessage(
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TypeError, "Cannot convert -inf to Rational.",
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R.from_float, -inf)
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self.assertRaisesMessage(
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TypeError, "Cannot convert nan to Rational.",
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R.from_float, nan)
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def testFromDecimal(self):
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self.assertRaisesMessage(
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TypeError,
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"Rational.from_decimal() only takes Decimals, not 3 (int)",
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R.from_decimal, 3)
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self.assertEquals(R(0), R.from_decimal(Decimal("-0")))
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self.assertEquals(R(5, 10), R.from_decimal(Decimal("0.5")))
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self.assertEquals(R(5, 1000), R.from_decimal(Decimal("5e-3")))
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self.assertEquals(R(5000), R.from_decimal(Decimal("5e3")))
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self.assertEquals(1 - R(1, 10**30),
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R.from_decimal(Decimal("0." + "9" * 30)))
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self.assertRaisesMessage(
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TypeError, "Cannot convert Infinity to Rational.",
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R.from_decimal, Decimal("inf"))
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self.assertRaisesMessage(
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TypeError, "Cannot convert -Infinity to Rational.",
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R.from_decimal, Decimal("-inf"))
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self.assertRaisesMessage(
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TypeError, "Cannot convert NaN to Rational.",
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R.from_decimal, Decimal("nan"))
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self.assertRaisesMessage(
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TypeError, "Cannot convert sNaN to Rational.",
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R.from_decimal, Decimal("snan"))
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def testConversions(self):
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self.assertTypedEquals(-1, trunc(R(-11, 10)))
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self.assertTypedEquals(-2, R(-11, 10).__floor__())
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self.assertTypedEquals(-1, R(-11, 10).__ceil__())
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self.assertTypedEquals(-1, R(-10, 10).__ceil__())
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self.assertTypedEquals(0, R(-1, 10).__round__())
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self.assertTypedEquals(0, R(-5, 10).__round__())
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self.assertTypedEquals(-2, R(-15, 10).__round__())
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self.assertTypedEquals(-1, R(-7, 10).__round__())
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self.assertEquals(False, bool(R(0, 1)))
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self.assertEquals(True, bool(R(3, 2)))
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self.assertTypedEquals(0.1, float(R(1, 10)))
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# Check that __float__ isn't implemented by converting the
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# numerator and denominator to float before dividing.
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self.assertRaises(OverflowError, float, long('2'*400+'7'))
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self.assertAlmostEquals(2.0/3,
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float(R(long('2'*400+'7'), long('3'*400+'1'))))
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self.assertTypedEquals(0.1+0j, complex(R(1,10)))
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def testRound(self):
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self.assertTypedEquals(R(-200), R(-150).__round__(-2))
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self.assertTypedEquals(R(-200), R(-250).__round__(-2))
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self.assertTypedEquals(R(30), R(26).__round__(-1))
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self.assertTypedEquals(R(-2, 10), R(-15, 100).__round__(1))
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self.assertTypedEquals(R(-2, 10), R(-25, 100).__round__(1))
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def testArithmetic(self):
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self.assertEquals(R(1, 2), R(1, 10) + R(2, 5))
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self.assertEquals(R(-3, 10), R(1, 10) - R(2, 5))
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self.assertEquals(R(1, 25), R(1, 10) * R(2, 5))
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self.assertEquals(R(1, 4), R(1, 10) / R(2, 5))
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self.assertTypedEquals(2, R(9, 10) // R(2, 5))
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self.assertTypedEquals(10**23, R(10**23, 1) // R(1))
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self.assertEquals(R(2, 3), R(-7, 3) % R(3, 2))
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self.assertEquals(R(8, 27), R(2, 3) ** R(3))
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self.assertEquals(R(27, 8), R(2, 3) ** R(-3))
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self.assertTypedEquals(2.0, R(4) ** R(1, 2))
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# Will return 1j in 3.0:
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self.assertRaises(ValueError, pow, R(-1), R(1, 2))
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def testMixedArithmetic(self):
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self.assertTypedEquals(R(11, 10), R(1, 10) + 1)
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self.assertTypedEquals(1.1, R(1, 10) + 1.0)
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self.assertTypedEquals(1.1 + 0j, R(1, 10) + (1.0 + 0j))
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self.assertTypedEquals(R(11, 10), 1 + R(1, 10))
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self.assertTypedEquals(1.1, 1.0 + R(1, 10))
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self.assertTypedEquals(1.1 + 0j, (1.0 + 0j) + R(1, 10))
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self.assertTypedEquals(R(-9, 10), R(1, 10) - 1)
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self.assertTypedEquals(-0.9, R(1, 10) - 1.0)
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self.assertTypedEquals(-0.9 + 0j, R(1, 10) - (1.0 + 0j))
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self.assertTypedEquals(R(9, 10), 1 - R(1, 10))
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self.assertTypedEquals(0.9, 1.0 - R(1, 10))
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self.assertTypedEquals(0.9 + 0j, (1.0 + 0j) - R(1, 10))
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self.assertTypedEquals(R(1, 10), R(1, 10) * 1)
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self.assertTypedEquals(0.1, R(1, 10) * 1.0)
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self.assertTypedEquals(0.1 + 0j, R(1, 10) * (1.0 + 0j))
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self.assertTypedEquals(R(1, 10), 1 * R(1, 10))
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self.assertTypedEquals(0.1, 1.0 * R(1, 10))
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self.assertTypedEquals(0.1 + 0j, (1.0 + 0j) * R(1, 10))
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self.assertTypedEquals(R(1, 10), R(1, 10) / 1)
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self.assertTypedEquals(0.1, R(1, 10) / 1.0)
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self.assertTypedEquals(0.1 + 0j, R(1, 10) / (1.0 + 0j))
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self.assertTypedEquals(R(10, 1), 1 / R(1, 10))
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self.assertTypedEquals(10.0, 1.0 / R(1, 10))
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self.assertTypedEquals(10.0 + 0j, (1.0 + 0j) / R(1, 10))
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self.assertTypedEquals(0, R(1, 10) // 1)
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self.assertTypedEquals(0.0, R(1, 10) // 1.0)
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self.assertTypedEquals(10, 1 // R(1, 10))
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self.assertTypedEquals(10**23, 10**22 // R(1, 10))
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self.assertTypedEquals(10.0, 1.0 // R(1, 10))
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self.assertTypedEquals(R(1, 10), R(1, 10) % 1)
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self.assertTypedEquals(0.1, R(1, 10) % 1.0)
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self.assertTypedEquals(R(0, 1), 1 % R(1, 10))
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self.assertTypedEquals(0.0, 1.0 % R(1, 10))
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# No need for divmod since we don't override it.
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# ** has more interesting conversion rules.
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self.assertTypedEquals(R(100, 1), R(1, 10) ** -2)
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self.assertTypedEquals(R(100, 1), R(10, 1) ** 2)
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self.assertTypedEquals(0.1, R(1, 10) ** 1.0)
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self.assertTypedEquals(0.1 + 0j, R(1, 10) ** (1.0 + 0j))
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self.assertTypedEquals(4 , 2 ** R(2, 1))
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# Will return 1j in 3.0:
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self.assertRaises(ValueError, pow, (-1), R(1, 2))
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self.assertTypedEquals(R(1, 4) , 2 ** R(-2, 1))
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self.assertTypedEquals(2.0 , 4 ** R(1, 2))
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self.assertTypedEquals(0.25, 2.0 ** R(-2, 1))
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self.assertTypedEquals(1.0 + 0j, (1.0 + 0j) ** R(1, 10))
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def testMixingWithDecimal(self):
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# Decimal refuses mixed comparisons.
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self.assertRaisesMessage(
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TypeError,
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"unsupported operand type(s) for +: 'Rational' and 'Decimal'",
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operator.add, R(3,11), Decimal('3.1415926'))
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self.assertNotEquals(R(5, 2), Decimal('2.5'))
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def testComparisons(self):
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self.assertTrue(R(1, 2) < R(2, 3))
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self.assertFalse(R(1, 2) < R(1, 2))
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self.assertTrue(R(1, 2) <= R(2, 3))
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self.assertTrue(R(1, 2) <= R(1, 2))
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self.assertFalse(R(2, 3) <= R(1, 2))
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self.assertTrue(R(1, 2) == R(1, 2))
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self.assertFalse(R(1, 2) == R(1, 3))
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def testMixedLess(self):
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self.assertTrue(2 < R(5, 2))
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self.assertFalse(2 < R(4, 2))
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self.assertTrue(R(5, 2) < 3)
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self.assertFalse(R(4, 2) < 2)
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self.assertTrue(R(1, 2) < 0.6)
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self.assertFalse(R(1, 2) < 0.4)
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self.assertTrue(0.4 < R(1, 2))
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self.assertFalse(0.5 < R(1, 2))
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def testMixedLessEqual(self):
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self.assertTrue(0.5 <= R(1, 2))
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self.assertFalse(0.6 <= R(1, 2))
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self.assertTrue(R(1, 2) <= 0.5)
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self.assertFalse(R(1, 2) <= 0.4)
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self.assertTrue(2 <= R(4, 2))
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self.assertFalse(2 <= R(3, 2))
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self.assertTrue(R(4, 2) <= 2)
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self.assertFalse(R(5, 2) <= 2)
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def testBigFloatComparisons(self):
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# Because 10**23 can't be represented exactly as a float:
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self.assertFalse(R(10**23) == float(10**23))
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# The first test demonstrates why these are important.
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self.assertFalse(1e23 < float(R(trunc(1e23) + 1)))
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self.assertTrue(1e23 < R(trunc(1e23) + 1))
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self.assertFalse(1e23 <= R(trunc(1e23) - 1))
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self.assertTrue(1e23 > R(trunc(1e23) - 1))
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self.assertFalse(1e23 >= R(trunc(1e23) + 1))
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def testBigComplexComparisons(self):
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self.assertFalse(R(10**23) == complex(10**23))
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self.assertTrue(R(10**23) > complex(10**23))
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self.assertFalse(R(10**23) <= complex(10**23))
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def testMixedEqual(self):
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self.assertTrue(0.5 == R(1, 2))
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self.assertFalse(0.6 == R(1, 2))
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self.assertTrue(R(1, 2) == 0.5)
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self.assertFalse(R(1, 2) == 0.4)
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self.assertTrue(2 == R(4, 2))
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self.assertFalse(2 == R(3, 2))
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self.assertTrue(R(4, 2) == 2)
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self.assertFalse(R(5, 2) == 2)
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def testStringification(self):
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self.assertEquals("Rational(7,3)", repr(R(7, 3)))
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self.assertEquals("7/3", str(R(7, 3)))
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self.assertEquals("7", str(R(7, 1)))
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def testHash(self):
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self.assertEquals(hash(2.5), hash(R(5, 2)))
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self.assertEquals(hash(10**50), hash(R(10**50)))
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self.assertNotEquals(hash(float(10**23)), hash(R(10**23)))
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def testApproximatePi(self):
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# Algorithm borrowed from
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# http://docs.python.org/lib/decimal-recipes.html
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three = R(3)
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lasts, t, s, n, na, d, da = 0, three, 3, 1, 0, 0, 24
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while abs(s - lasts) > R(1, 10**9):
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lasts = s
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n, na = n+na, na+8
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d, da = d+da, da+32
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t = (t * n) / d
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s += t
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self.assertAlmostEquals(math.pi, s)
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def testApproximateCos1(self):
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# Algorithm borrowed from
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# http://docs.python.org/lib/decimal-recipes.html
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x = R(1)
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i, lasts, s, fact, num, sign = 0, 0, R(1), 1, 1, 1
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while abs(s - lasts) > R(1, 10**9):
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lasts = s
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i += 2
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fact *= i * (i-1)
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num *= x * x
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sign *= -1
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s += num / fact * sign
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self.assertAlmostEquals(math.cos(1), s)
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def test_main():
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run_unittest(RationalTest)
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if __name__ == '__main__':
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test_main()
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