summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_binop.py
blob: 5f3ba8b402b98455d0e6465e63afcc876a8a483c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
"""Tests for binary operators on subtypes of built-in types."""

import unittest
from test import support
from operator import eq, ne, lt, gt, le, ge

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, 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 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 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.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):
    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 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__'])

def test_main():
    support.run_unittest(RatTestCase, OperationOrderTests)

if __name__ == "__main__":
    test_main()