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v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 1da43e5e916949c8e849e656d9d05fa4b9d6836c authored by Benjamin Peterson on 26 June 2009, 13:21:52 UTC
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
Tip revision: 1da43e5
test_binop.py
"""Tests for binary operators on subtypes of built-in types."""
import unittest
from test import support
def gcd(a, b):
"""Greatest common divisor using Euclid's algorithm."""
while a:
a, b = b%a, a
return b
def isint(x):
"""Test whether an object is an instance of int or long."""
return isinstance(x, int) or isinstance(x, int)
def isnum(x):
"""Test whether an object is an instance of a built-in numeric type."""
for T in int, int, float, complex:
if isinstance(x, T):
return 1
return 0
def isRat(x):
"""Test wheter an object is an instance of the Rat class."""
return isinstance(x, Rat)
class Rat(object):
"""Rational number implemented as a normalized pair of longs."""
__slots__ = ['_Rat__num', '_Rat__den']
def __init__(self, num=0, den=1):
"""Constructor: Rat([num[, den]]).
The arguments must be ints or longs, and default to (0, 1)."""
if not isint(num):
raise TypeError("Rat numerator must be int or long (%r)" % num)
if not isint(den):
raise TypeError("Rat denominator must be int or long (%r)" % den)
# But the zero is always on
if den == 0:
raise ZeroDivisionError("zero denominator")
g = gcd(den, num)
self.__num = int(num//g)
self.__den = int(den//g)
def _get_num(self):
"""Accessor function for read-only 'num' attribute of Rat."""
return self.__num
num = property(_get_num, None)
def _get_den(self):
"""Accessor function for read-only 'den' attribute of Rat."""
return self.__den
den = property(_get_den, None)
def __repr__(self):
"""Convert a Rat to an string resembling a Rat constructor call."""
return "Rat(%d, %d)" % (self.__num, self.__den)
def __str__(self):
"""Convert a Rat to a string resembling a decimal numeric value."""
return str(float(self))
def __float__(self):
"""Convert a Rat to a float."""
return self.__num*1.0/self.__den
def __int__(self):
"""Convert a Rat to an int; self.den must be 1."""
if self.__den == 1:
try:
return int(self.__num)
except OverflowError:
raise OverflowError("%s too large to convert to int" %
repr(self))
raise ValueError("can't convert %s to int" % repr(self))
def __add__(self, other):
"""Add two Rats, or a Rat and a number."""
if isint(other):
other = Rat(other)
if isRat(other):
return Rat(self.__num*other.__den + other.__num*self.__den,
self.__den*other.__den)
if isnum(other):
return float(self) + other
return NotImplemented
__radd__ = __add__
def __sub__(self, other):
"""Subtract two Rats, or a Rat and a number."""
if isint(other):
other = Rat(other)
if isRat(other):
return Rat(self.__num*other.__den - other.__num*self.__den,
self.__den*other.__den)
if isnum(other):
return float(self) - other
return NotImplemented
def __rsub__(self, other):
"""Subtract two Rats, or a Rat and a number (reversed args)."""
if isint(other):
other = Rat(other)
if isRat(other):
return Rat(other.__num*self.__den - self.__num*other.__den,
self.__den*other.__den)
if isnum(other):
return other - float(self)
return NotImplemented
def __mul__(self, other):
"""Multiply two Rats, or a Rat and a number."""
if isRat(other):
return Rat(self.__num*other.__num, self.__den*other.__den)
if isint(other):
return Rat(self.__num*other, self.__den)
if isnum(other):
return float(self)*other
return NotImplemented
__rmul__ = __mul__
def __truediv__(self, other):
"""Divide two Rats, or a Rat and a number."""
if isRat(other):
return Rat(self.__num*other.__den, self.__den*other.__num)
if isint(other):
return Rat(self.__num, self.__den*other)
if isnum(other):
return float(self) / other
return NotImplemented
def __rtruediv__(self, other):
"""Divide two Rats, or a Rat and a number (reversed args)."""
if isRat(other):
return Rat(other.__num*self.__den, other.__den*self.__num)
if isint(other):
return Rat(other*self.__den, self.__num)
if isnum(other):
return other / float(self)
return NotImplemented
def __floordiv__(self, other):
"""Divide two Rats, returning the floored result."""
if isint(other):
other = Rat(other)
elif not isRat(other):
return NotImplemented
x = self/other
return x.__num // x.__den
def __rfloordiv__(self, other):
"""Divide two Rats, returning the floored result (reversed args)."""
x = other/self
return x.__num // x.__den
def __divmod__(self, other):
"""Divide two Rats, returning quotient and remainder."""
if isint(other):
other = Rat(other)
elif not isRat(other):
return NotImplemented
x = self//other
return (x, self - other * x)
def __rdivmod__(self, other):
"""Divide two Rats, returning quotient and remainder (reversed args)."""
if isint(other):
other = Rat(other)
elif not isRat(other):
return NotImplemented
return divmod(other, self)
def __mod__(self, other):
"""Take one Rat modulo another."""
return divmod(self, other)[1]
def __rmod__(self, other):
"""Take one Rat modulo another (reversed args)."""
return divmod(other, self)[1]
def __eq__(self, other):
"""Compare two Rats for equality."""
if isint(other):
return self.__den == 1 and self.__num == other
if isRat(other):
return self.__num == other.__num and self.__den == other.__den
if isnum(other):
return float(self) == other
return NotImplemented
def __ne__(self, other):
"""Compare two Rats for inequality."""
return not self == other
class RatTestCase(unittest.TestCase):
"""Unit tests for Rat class and its support utilities."""
def test_gcd(self):
self.assertEqual(gcd(10, 12), 2)
self.assertEqual(gcd(10, 15), 5)
self.assertEqual(gcd(10, 11), 1)
self.assertEqual(gcd(100, 15), 5)
self.assertEqual(gcd(-10, 2), -2)
self.assertEqual(gcd(10, -2), 2)
self.assertEqual(gcd(-10, -2), -2)
for i in range(1, 20):
for j in range(1, 20):
self.assert_(gcd(i, j) > 0)
self.assert_(gcd(-i, j) < 0)
self.assert_(gcd(i, -j) > 0)
self.assert_(gcd(-i, -j) < 0)
def test_constructor(self):
a = Rat(10, 15)
self.assertEqual(a.num, 2)
self.assertEqual(a.den, 3)
a = Rat(10, 15)
self.assertEqual(a.num, 2)
self.assertEqual(a.den, 3)
a = Rat(10, -15)
self.assertEqual(a.num, -2)
self.assertEqual(a.den, 3)
a = Rat(-10, 15)
self.assertEqual(a.num, -2)
self.assertEqual(a.den, 3)
a = Rat(-10, -15)
self.assertEqual(a.num, 2)
self.assertEqual(a.den, 3)
a = Rat(7)
self.assertEqual(a.num, 7)
self.assertEqual(a.den, 1)
try:
a = Rat(1, 0)
except ZeroDivisionError:
pass
else:
self.fail("Rat(1, 0) didn't raise ZeroDivisionError")
for bad in "0", 0.0, 0j, (), [], {}, None, Rat, unittest:
try:
a = Rat(bad)
except TypeError:
pass
else:
self.fail("Rat(%r) didn't raise TypeError" % bad)
try:
a = Rat(1, bad)
except TypeError:
pass
else:
self.fail("Rat(1, %r) didn't raise TypeError" % bad)
def test_add(self):
self.assertEqual(Rat(2, 3) + Rat(1, 3), 1)
self.assertEqual(Rat(2, 3) + 1, Rat(5, 3))
self.assertEqual(1 + Rat(2, 3), Rat(5, 3))
self.assertEqual(1.0 + Rat(1, 2), 1.5)
self.assertEqual(Rat(1, 2) + 1.0, 1.5)
def test_sub(self):
self.assertEqual(Rat(7, 2) - Rat(7, 5), Rat(21, 10))
self.assertEqual(Rat(7, 5) - 1, Rat(2, 5))
self.assertEqual(1 - Rat(3, 5), Rat(2, 5))
self.assertEqual(Rat(3, 2) - 1.0, 0.5)
self.assertEqual(1.0 - Rat(1, 2), 0.5)
def test_mul(self):
self.assertEqual(Rat(2, 3) * Rat(5, 7), Rat(10, 21))
self.assertEqual(Rat(10, 3) * 3, 10)
self.assertEqual(3 * Rat(10, 3), 10)
self.assertEqual(Rat(10, 5) * 0.5, 1.0)
self.assertEqual(0.5 * Rat(10, 5), 1.0)
def test_div(self):
self.assertEqual(Rat(10, 3) / Rat(5, 7), Rat(14, 3))
self.assertEqual(Rat(10, 3) / 3, Rat(10, 9))
self.assertEqual(2 / Rat(5), Rat(2, 5))
self.assertEqual(3.0 * Rat(1, 2), 1.5)
self.assertEqual(Rat(1, 2) * 3.0, 1.5)
def test_floordiv(self):
self.assertEqual(Rat(10) // Rat(4), 2)
self.assertEqual(Rat(10, 3) // Rat(4, 3), 2)
self.assertEqual(Rat(10) // 4, 2)
self.assertEqual(10 // Rat(4), 2)
def test_eq(self):
self.assertEqual(Rat(10), Rat(20, 2))
self.assertEqual(Rat(10), 10)
self.assertEqual(10, Rat(10))
self.assertEqual(Rat(10), 10.0)
self.assertEqual(10.0, Rat(10))
def test_true_div(self):
self.assertEqual(Rat(10, 3) / Rat(5, 7), Rat(14, 3))
self.assertEqual(Rat(10, 3) / 3, Rat(10, 9))
self.assertEqual(2 / Rat(5), Rat(2, 5))
self.assertEqual(3.0 * Rat(1, 2), 1.5)
self.assertEqual(Rat(1, 2) * 3.0, 1.5)
self.assertEqual(eval('1/2'), 0.5)
# XXX Ran out of steam; TO DO: divmod, div, future division
def test_main():
support.run_unittest(RatTestCase)
if __name__ == "__main__":
test_main()