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Þ'¯°ÌME[YéïĵÂCå½ Ué©Áû'Ê9%eÔðNU”ë‘ÌsD3/®+UI˜9h.WC”빓$#:pz:YÓ ¿xž* ³$Í +$kñAŠ‹†¢ Uê>¸)_š¬÷©ßAÂÔb9ÇU ¯¾á•9¯ÏÏ÷O÷¼¼Fähal1‰3Ì[Ïr•´UCksNÐ] R‘¸¥H+§Šé†c©vÖÞ0iÓ76s†î!§=ß ¼~Ô'°Ãmäoäš³ªøi1úÉ)³yV8 CLÄØÁ‘WYïi€H6ÖÑiámø^ÈY´°Ñ7¥Û*—Ñ©L«Qƒï—Ùrÿ ›£Ð*š¸ˆL©ˆ$ˆ ÷¾D§9È®«qbqC)–ˆïv´çñsÑVT­Ø, <àïºÀO«Jý·õ àfPìð .wFšir´þ’2_Y *Æ€x\« ì€9š@ Ž|F⇥ˆkZ@hÖÄ0t¿-<“‹qµ¾*ZL¤Ú)&BJpÓF5=$„at*Zš$’ÑtdûÝRI1 2Ž‰$€$I$#‰SÞ’Hë¬ï;Á$¡t$’`<(ñÇt)$‡Ð.Êf¢X’Kt=Éé$‚ˆªè¢oÝëòI%Rgcª÷ŠyI%¡‰ÿ !ñ)´õ $¤ Ô’IIGÿÙ"""Tests for binary operators on subtypes of built-in types.""" import unittest from operator import eq, le, ne from abc import ABCMeta 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.""" return isinstance(x, int) def isnum(x): """Test whether an object is an instance of a built-in numeric type.""" for T in int, float, complex: if isinstance(x, T): return 1 return 0 def isRat(x): """Test whether an object is an instance of the Rat class.""" return isinstance(x, Rat) class Rat(object): """Rational number implemented as a normalized pair of ints.""" __slots__ = ['_Rat__num', '_Rat__den'] def __init__(self, num=0, den=1): """Constructor: Rat([num[, den]]). The arguments must be ints, and default to (0, 1).""" if not isint(num): raise TypeError("Rat numerator must be int (%r)" % num) if not isint(den): raise TypeError("Rat denominator must be int (%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 a 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 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.assertTrue(gcd(i, j) > 0) self.assertTrue(gcd(-i, j) < 0) self.assertTrue(gcd(i, -j) > 0) self.assertTrue(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(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 class OperationLogger: """Base class for classes with operation logging.""" def __init__(self, logger): self.logger = logger def log_operation(self, *args): self.logger(*args) def op_sequence(op, *classes): """Return the sequence of operations that results from applying the operation `op` to instances of the given classes.""" log = [] instances = [] for c in classes: instances.append(c(log.append)) try: op(*instances) except TypeError: pass return log class A(OperationLogger): def __eq__(self, other): self.log_operation('A.__eq__') return NotImplemented def __le__(self, other): self.log_operation('A.__le__') return NotImplemented def __ge__(self, other): self.log_operation('A.__ge__') return NotImplemented class B(OperationLogger, metaclass=ABCMeta): def __eq__(self, other): self.log_operation('B.__eq__') return NotImplemented def __le__(self, other): self.log_operation('B.__le__') return NotImplemented def __ge__(self, other): self.log_operation('B.__ge__') return NotImplemented class C(B): def __eq__(self, other): self.log_operation('C.__eq__') return NotImplemented def __le__(self, other): self.log_operation('C.__le__') return NotImplemented def __ge__(self, other): self.log_operation('C.__ge__') return NotImplemented class V(OperationLogger): """Virtual subclass of B""" def __eq__(self, other): self.log_operation('V.__eq__') return NotImplemented def __le__(self, other): self.log_operation('V.__le__') return NotImplemented def __ge__(self, other): self.log_operation('V.__ge__') return NotImplemented B.register(V) class OperationOrderTests(unittest.TestCase): def test_comparison_orders(self): self.assertEqual(op_sequence(eq, A, A), ['A.__eq__', 'A.__eq__']) self.assertEqual(op_sequence(eq, A, B), ['A.__eq__', 'B.__eq__']) self.assertEqual(op_sequence(eq, B, A), ['B.__eq__', 'A.__eq__']) # C is a subclass of B, so C.__eq__ is called first self.assertEqual(op_sequence(eq, B, C), ['C.__eq__', 'B.__eq__']) self.assertEqual(op_sequence(eq, C, B), ['C.__eq__', 'B.__eq__']) self.assertEqual(op_sequence(le, A, A), ['A.__le__', 'A.__ge__']) self.assertEqual(op_sequence(le, A, B), ['A.__le__', 'B.__ge__']) self.assertEqual(op_sequence(le, B, A), ['B.__le__', 'A.__ge__']) self.assertEqual(op_sequence(le, B, C), ['C.__ge__', 'B.__le__']) self.assertEqual(op_sequence(le, C, B), ['C.__le__', 'B.__ge__']) self.assertTrue(issubclass(V, B)) self.assertEqual(op_sequence(eq, B, V), ['B.__eq__', 'V.__eq__']) self.assertEqual(op_sequence(le, B, V), ['B.__le__', 'V.__ge__']) class SupEq(object): """Class that can test equality""" def __eq__(self, other): return True class S(SupEq): """Subclass of SupEq that should fail""" __eq__ = None class F(object): """Independent class that should fall back""" class X(object): """Independent class that should fail""" __eq__ = None class SN(SupEq): """Subclass of SupEq that can test equality, but not non-equality""" __ne__ = None class XN: """Independent class that can test equality, but not non-equality""" def __eq__(self, other): return True __ne__ = None class FallbackBlockingTests(unittest.TestCase): """Unit tests for None method blocking""" def test_fallback_rmethod_blocking(self): e, f, s, x = SupEq(), F(), S(), X() self.assertEqual(e, e) self.assertEqual(e, f) self.assertEqual(f, e) # left operand is checked first self.assertEqual(e, x) self.assertRaises(TypeError, eq, x, e) # S is a subclass, so it's always checked first self.assertRaises(TypeError, eq, e, s) self.assertRaises(TypeError, eq, s, e) def test_fallback_ne_blocking(self): e, sn, xn = SupEq(), SN(), XN() self.assertFalse(e != e) self.assertRaises(TypeError, ne, e, sn) self.assertRaises(TypeError, ne, sn, e) self.assertFalse(e != xn) self.assertRaises(TypeError, ne, xn, e) if __name__ == "__main__": unittest.main()