summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_format.py
blob: da635a9205a60983c60f3b6ad673c73cd68af490 (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
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
from test.support import verbose, TestFailed
import locale
import sys
import test.support as support
import unittest

maxsize = support.MAX_Py_ssize_t

# test string formatting operator (I am not sure if this is being tested
# elsewhere but, surely, some of the given cases are *not* tested because
# they crash python)
# test on bytes object as well

def testformat(formatstr, args, output=None, limit=None, overflowok=False):
    if verbose:
        if output:
            print("{!a} % {!a} =? {!a} ...".format(formatstr, args, output),
                  end=' ')
        else:
            print("{!a} % {!a} works? ...".format(formatstr, args), end=' ')
    try:
        result = formatstr % args
    except OverflowError:
        if not overflowok:
            raise
        if verbose:
            print('overflow (this is fine)')
    else:
        if output and limit is None and result != output:
            if verbose:
                print('no')
            raise AssertionError("%r %% %r == %r != %r" %
                                (formatstr, args, result, output))
        # when 'limit' is specified, it determines how many characters
        # must match exactly; lengths must always match.
        # ex: limit=5, '12345678' matches '12345___'
        # (mainly for floating point format tests for which an exact match
        # can't be guaranteed due to rounding and representation errors)
        elif output and limit is not None and (
                len(result)!=len(output) or result[:limit]!=output[:limit]):
            if verbose:
                print('no')
            print("%s %% %s == %s != %s" % \
                  (repr(formatstr), repr(args), repr(result), repr(output)))
        else:
            if verbose:
                print('yes')

def testcommon(formatstr, args, output=None, limit=None, overflowok=False):
    # if formatstr is a str, test str, bytes, and bytearray;
    # otherwise, test bytes and bytearry
    if isinstance(formatstr, str):
        testformat(formatstr, args, output, limit, overflowok)
        b_format = formatstr.encode('ascii')
    else:
        b_format = formatstr
    ba_format = bytearray(b_format)
    b_args = []
    if not isinstance(args, tuple):
        args = (args, )
    b_args = tuple(args)
    if output is None:
        b_output = ba_output = None
    else:
        if isinstance(output, str):
            b_output = output.encode('ascii')
        else:
            b_output = output
        ba_output = bytearray(b_output)
    testformat(b_format, b_args, b_output, limit, overflowok)
    testformat(ba_format, b_args, ba_output, limit, overflowok)


class FormatTest(unittest.TestCase):

    def test_common_format(self):
        # test the format identifiers that work the same across
        # str, bytes, and bytearrays (integer, float, oct, hex)
        testcommon("%.1d", (1,), "1")
        testcommon("%.*d", (sys.maxsize,1), overflowok=True)  # expect overflow
        testcommon("%.100d", (1,), '00000000000000000000000000000000000000'
                 '000000000000000000000000000000000000000000000000000000'
                 '00000001', overflowok=True)
        testcommon("%#.117x", (1,), '0x00000000000000000000000000000000000'
                 '000000000000000000000000000000000000000000000000000000'
                 '0000000000000000000000000001',
                 overflowok=True)
        testcommon("%#.118x", (1,), '0x00000000000000000000000000000000000'
                 '000000000000000000000000000000000000000000000000000000'
                 '00000000000000000000000000001',
                 overflowok=True)

        testcommon("%f", (1.0,), "1.000000")
        # these are trying to test the limits of the internal magic-number-length
        # formatting buffer, if that number changes then these tests are less
        # effective
        testcommon("%#.*g", (109, -1.e+49/3.))
        testcommon("%#.*g", (110, -1.e+49/3.))
        testcommon("%#.*g", (110, -1.e+100/3.))
        # test some ridiculously large precision, expect overflow
        testcommon('%12.*f', (123456, 1.0))

        # check for internal overflow validation on length of precision
        # these tests should no longer cause overflow in Python
        # 2.7/3.1 and later.
        testcommon("%#.*g", (110, -1.e+100/3.))
        testcommon("%#.*G", (110, -1.e+100/3.))
        testcommon("%#.*f", (110, -1.e+100/3.))
        testcommon("%#.*F", (110, -1.e+100/3.))
        # Formatting of integers. Overflow is not ok
        testcommon("%x", 10, "a")
        testcommon("%x", 100000000000, "174876e800")
        testcommon("%o", 10, "12")
        testcommon("%o", 100000000000, "1351035564000")
        testcommon("%d", 10, "10")
        testcommon("%d", 100000000000, "100000000000")

        big = 123456789012345678901234567890
        testcommon("%d", big, "123456789012345678901234567890")
        testcommon("%d", -big, "-123456789012345678901234567890")
        testcommon("%5d", -big, "-123456789012345678901234567890")
        testcommon("%31d", -big, "-123456789012345678901234567890")
        testcommon("%32d", -big, " -123456789012345678901234567890")
        testcommon("%-32d", -big, "-123456789012345678901234567890 ")
        testcommon("%032d", -big, "-0123456789012345678901234567890")
        testcommon("%-032d", -big, "-123456789012345678901234567890 ")
        testcommon("%034d", -big, "-000123456789012345678901234567890")
        testcommon("%034d", big, "0000123456789012345678901234567890")
        testcommon("%0+34d", big, "+000123456789012345678901234567890")
        testcommon("%+34d", big, "   +123456789012345678901234567890")
        testcommon("%34d", big, "    123456789012345678901234567890")
        testcommon("%.2d", big, "123456789012345678901234567890")
        testcommon("%.30d", big, "123456789012345678901234567890")
        testcommon("%.31d", big, "0123456789012345678901234567890")
        testcommon("%32.31d", big, " 0123456789012345678901234567890")
        testcommon("%d", float(big), "123456________________________", 6)

        big = 0x1234567890abcdef12345  # 21 hex digits
        testcommon("%x", big, "1234567890abcdef12345")
        testcommon("%x", -big, "-1234567890abcdef12345")
        testcommon("%5x", -big, "-1234567890abcdef12345")
        testcommon("%22x", -big, "-1234567890abcdef12345")
        testcommon("%23x", -big, " -1234567890abcdef12345")
        testcommon("%-23x", -big, "-1234567890abcdef12345 ")
        testcommon("%023x", -big, "-01234567890abcdef12345")
        testcommon("%-023x", -big, "-1234567890abcdef12345 ")
        testcommon("%025x", -big, "-0001234567890abcdef12345")
        testcommon("%025x", big, "00001234567890abcdef12345")
        testcommon("%0+25x", big, "+0001234567890abcdef12345")
        testcommon("%+25x", big, "   +1234567890abcdef12345")
        testcommon("%25x", big, "    1234567890abcdef12345")
        testcommon("%.2x", big, "1234567890abcdef12345")
        testcommon("%.21x", big, "1234567890abcdef12345")
        testcommon("%.22x", big, "01234567890abcdef12345")
        testcommon("%23.22x", big, " 01234567890abcdef12345")
        testcommon("%-23.22x", big, "01234567890abcdef12345 ")
        testcommon("%X", big, "1234567890ABCDEF12345")
        testcommon("%#X", big, "0X1234567890ABCDEF12345")
        testcommon("%#x", big, "0x1234567890abcdef12345")
        testcommon("%#x", -big, "-0x1234567890abcdef12345")
        testcommon("%#27x", big, "    0x1234567890abcdef12345")
        testcommon("%#-27x", big, "0x1234567890abcdef12345    ")
        testcommon("%#027x", big, "0x00001234567890abcdef12345")
        testcommon("%#.23x", big, "0x001234567890abcdef12345")
        testcommon("%#.23x", -big, "-0x001234567890abcdef12345")
        testcommon("%#27.23x", big, "  0x001234567890abcdef12345")
        testcommon("%#-27.23x", big, "0x001234567890abcdef12345  ")
        testcommon("%#027.23x", big, "0x00001234567890abcdef12345")
        testcommon("%#+.23x", big, "+0x001234567890abcdef12345")
        testcommon("%# .23x", big, " 0x001234567890abcdef12345")
        testcommon("%#+.23X", big, "+0X001234567890ABCDEF12345")
        # next one gets two leading zeroes from precision, and another from the
        # 0 flag and the width
        testcommon("%#+027.23X", big, "+0X0001234567890ABCDEF12345")
        testcommon("%# 027.23X", big, " 0X0001234567890ABCDEF12345")
        # same, except no 0 flag
        testcommon("%#+27.23X", big, " +0X001234567890ABCDEF12345")
        testcommon("%#-+27.23x", big, "+0x001234567890abcdef12345 ")
        testcommon("%#- 27.23x", big, " 0x001234567890abcdef12345 ")

        big = 0o12345670123456701234567012345670  # 32 octal digits
        testcommon("%o", big, "12345670123456701234567012345670")
        testcommon("%o", -big, "-12345670123456701234567012345670")
        testcommon("%5o", -big, "-12345670123456701234567012345670")
        testcommon("%33o", -big, "-12345670123456701234567012345670")
        testcommon("%34o", -big, " -12345670123456701234567012345670")
        testcommon("%-34o", -big, "-12345670123456701234567012345670 ")
        testcommon("%034o", -big, "-012345670123456701234567012345670")
        testcommon("%-034o", -big, "-12345670123456701234567012345670 ")
        testcommon("%036o", -big, "-00012345670123456701234567012345670")
        testcommon("%036o", big, "000012345670123456701234567012345670")
        testcommon("%0+36o", big, "+00012345670123456701234567012345670")
        testcommon("%+36o", big, "   +12345670123456701234567012345670")
        testcommon("%36o", big, "    12345670123456701234567012345670")
        testcommon("%.2o", big, "12345670123456701234567012345670")
        testcommon("%.32o", big, "12345670123456701234567012345670")
        testcommon("%.33o", big, "012345670123456701234567012345670")
        testcommon("%34.33o", big, " 012345670123456701234567012345670")
        testcommon("%-34.33o", big, "012345670123456701234567012345670 ")
        testcommon("%o", big, "12345670123456701234567012345670")
        testcommon("%#o", big, "0o12345670123456701234567012345670")
        testcommon("%#o", -big, "-0o12345670123456701234567012345670")
        testcommon("%#38o", big, "    0o12345670123456701234567012345670")
        testcommon("%#-38o", big, "0o12345670123456701234567012345670    ")
        testcommon("%#038o", big, "0o000012345670123456701234567012345670")
        testcommon("%#.34o", big, "0o0012345670123456701234567012345670")
        testcommon("%#.34o", -big, "-0o0012345670123456701234567012345670")
        testcommon("%#38.34o", big, "  0o0012345670123456701234567012345670")
        testcommon("%#-38.34o", big, "0o0012345670123456701234567012345670  ")
        testcommon("%#038.34o", big, "0o000012345670123456701234567012345670")
        testcommon("%#+.34o", big, "+0o0012345670123456701234567012345670")
        testcommon("%# .34o", big, " 0o0012345670123456701234567012345670")
        testcommon("%#+38.34o", big, " +0o0012345670123456701234567012345670")
        testcommon("%#-+38.34o", big, "+0o0012345670123456701234567012345670 ")
        testcommon("%#- 38.34o", big, " 0o0012345670123456701234567012345670 ")
        testcommon("%#+038.34o", big, "+0o00012345670123456701234567012345670")
        testcommon("%# 038.34o", big, " 0o00012345670123456701234567012345670")
        # next one gets one leading zero from precision
        testcommon("%.33o", big, "012345670123456701234567012345670")
        # base marker added in spite of leading zero (different to Python 2)
        testcommon("%#.33o", big, "0o012345670123456701234567012345670")
        # reduce precision, and base marker is always added
        testcommon("%#.32o", big, "0o12345670123456701234567012345670")
        # one leading zero from precision, plus two from "0" flag & width
        testcommon("%035.33o", big, "00012345670123456701234567012345670")
        # base marker shouldn't change the size
        testcommon("%0#35.33o", big, "0o012345670123456701234567012345670")

        # Some small ints, in both Python int and flavors).
        testcommon("%d", 42, "42")
        testcommon("%d", -42, "-42")
        testcommon("%d", 42.0, "42")
        testcommon("%#x", 1, "0x1")
        testcommon("%#X", 1, "0X1")
        testcommon("%#o", 1, "0o1")
        testcommon("%#o", 0, "0o0")
        testcommon("%o", 0, "0")
        testcommon("%d", 0, "0")
        testcommon("%#x", 0, "0x0")
        testcommon("%#X", 0, "0X0")
        testcommon("%x", 0x42, "42")
        testcommon("%x", -0x42, "-42")
        testcommon("%o", 0o42, "42")
        testcommon("%o", -0o42, "-42")
        # alternate float formatting
        testcommon('%g', 1.1, '1.1')
        testcommon('%#g', 1.1, '1.10000')

    def test_str_format(self):
        testformat("%r", "\u0378", "'\\u0378'")  # non printable
        testformat("%a", "\u0378", "'\\u0378'")  # non printable
        testformat("%r", "\u0374", "'\u0374'")   # printable
        testformat("%a", "\u0374", "'\\u0374'")  # printable

        # Test exception for unknown format characters, etc.
        if verbose:
            print('Testing exceptions')
        def test_exc(formatstr, args, exception, excmsg):
            try:
                testformat(formatstr, args)
            except exception as exc:
                if str(exc) == excmsg:
                    if verbose:
                        print("yes")
                else:
                    if verbose: print('no')
                    print('Unexpected ', exception, ':', repr(str(exc)))
            except:
                if verbose: print('no')
                print('Unexpected exception')
                raise
            else:
                raise TestFailed('did not get expected exception: %s' % excmsg)
        test_exc('abc %b', 1, ValueError,
                 "unsupported format character 'b' (0x62) at index 5")
        #test_exc(unicode('abc %\u3000','raw-unicode-escape'), 1, ValueError,
        #         "unsupported format character '?' (0x3000) at index 5")
        test_exc('%d', '1', TypeError, "%d format: a number is required, not str")
        test_exc('%x', '1', TypeError, "%x format: an integer is required, not str")
        test_exc('%x', 3.14, TypeError, "%x format: an integer is required, not float")
        test_exc('%g', '1', TypeError, "must be real number, not str")
        test_exc('no format', '1', TypeError,
                 "not all arguments converted during string formatting")
        test_exc('%c', -1, OverflowError, "%c arg not in range(0x110000)")
        test_exc('%c', sys.maxunicode+1, OverflowError,
                 "%c arg not in range(0x110000)")
        #test_exc('%c', 2**128, OverflowError, "%c arg not in range(0x110000)")
        test_exc('%c', 3.14, TypeError, "%c requires int or char")
        test_exc('%c', 'ab', TypeError, "%c requires int or char")
        test_exc('%c', b'x', TypeError, "%c requires int or char")

        if maxsize == 2**31-1:
            # crashes 2.2.1 and earlier:
            try:
                "%*d"%(maxsize, -127)
            except MemoryError:
                pass
            else:
                raise TestFailed('"%*d"%(maxsize, -127) should fail')

    def test_bytes_and_bytearray_format(self):
        # %c will insert a single byte, either from an int in range(256), or
        # from a bytes argument of length 1, not from a str.
        testcommon(b"%c", 7, b"\x07")
        testcommon(b"%c", b"Z", b"Z")
        testcommon(b"%c", bytearray(b"Z"), b"Z")
        testcommon(b"%5c", 65, b"    A")
        testcommon(b"%-5c", 65, b"A    ")
        # %b will insert a series of bytes, either from a type that supports
        # the Py_buffer protocol, or something that has a __bytes__ method
        class FakeBytes(object):
            def __bytes__(self):
                return b'123'
        fb = FakeBytes()
        testcommon(b"%b", b"abc", b"abc")
        testcommon(b"%b", bytearray(b"def"), b"def")
        testcommon(b"%b", fb, b"123")
        # # %s is an alias for %b -- should only be used for Py2/3 code
        testcommon(b"%s", b"abc", b"abc")
        testcommon(b"%s", bytearray(b"def"), b"def")
        testcommon(b"%s", fb, b"123")
        # %a will give the equivalent of
        # repr(some_obj).encode('ascii', 'backslashreplace')
        testcommon(b"%a", 3.14, b"3.14")
        testcommon(b"%a", b"ghi", b"b'ghi'")
        testcommon(b"%a", "jkl", b"'jkl'")
        testcommon(b"%a", "\u0544", b"'\\u0544'")
        # %r is an alias for %a
        testcommon(b"%r", 3.14, b"3.14")
        testcommon(b"%r", b"ghi", b"b'ghi'")
        testcommon(b"%r", "jkl", b"'jkl'")
        testcommon(b"%r", "\u0544", b"'\\u0544'")

        # Test exception for unknown format characters, etc.
        if verbose:
            print('Testing exceptions')
        def test_exc(formatstr, args, exception, excmsg):
            try:
                testformat(formatstr, args)
            except exception as exc:
                if str(exc) == excmsg:
                    if verbose:
                        print("yes")
                else:
                    if verbose: print('no')
                    print('Unexpected ', exception, ':', repr(str(exc)))
            except:
                if verbose: print('no')
                print('Unexpected exception')
                raise
            else:
                raise TestFailed('did not get expected exception: %s' % excmsg)
        test_exc(b'%d', '1', TypeError,
                "%d format: a number is required, not str")
        test_exc(b'%d', b'1', TypeError,
                "%d format: a number is required, not bytes")
        test_exc(b'%x', 3.14, TypeError,
                "%x format: an integer is required, not float")
        test_exc(b'%g', '1', TypeError, "float argument required, not str")
        test_exc(b'%g', b'1', TypeError, "float argument required, not bytes")
        test_exc(b'no format', 7, TypeError,
                 "not all arguments converted during bytes formatting")
        test_exc(b'no format', b'1', TypeError,
                 "not all arguments converted during bytes formatting")
        test_exc(b'no format', bytearray(b'1'), TypeError,
                 "not all arguments converted during bytes formatting")
        test_exc(b"%c", -1, OverflowError,
                "%c arg not in range(256)")
        test_exc(b"%c", 256, OverflowError,
                "%c arg not in range(256)")
        test_exc(b"%c", 2**128, OverflowError,
                "%c arg not in range(256)")
        test_exc(b"%c", b"Za", TypeError,
                "%c requires an integer in range(256) or a single byte")
        test_exc(b"%c", "Y", TypeError,
                "%c requires an integer in range(256) or a single byte")
        test_exc(b"%c", 3.14, TypeError,
                "%c requires an integer in range(256) or a single byte")
        test_exc(b"%b", "Xc", TypeError,
                "%b requires bytes, or an object that implements __bytes__, not 'str'")
        test_exc(b"%s", "Wd", TypeError,
                "%b requires bytes, or an object that implements __bytes__, not 'str'")

        if maxsize == 2**31-1:
            # crashes 2.2.1 and earlier:
            try:
                "%*d"%(maxsize, -127)
            except MemoryError:
                pass
            else:
                raise TestFailed('"%*d"%(maxsize, -127) should fail')

    def test_non_ascii(self):
        testformat("\u20ac=%f", (1.0,), "\u20ac=1.000000")

        self.assertEqual(format("abc", "\u2007<5"), "abc\u2007\u2007")
        self.assertEqual(format(123, "\u2007<5"), "123\u2007\u2007")
        self.assertEqual(format(12.3, "\u2007<6"), "12.3\u2007\u2007")
        self.assertEqual(format(0j, "\u2007<4"), "0j\u2007\u2007")
        self.assertEqual(format(1+2j, "\u2007<8"), "(1+2j)\u2007\u2007")

        self.assertEqual(format("abc", "\u2007>5"), "\u2007\u2007abc")
        self.assertEqual(format(123, "\u2007>5"), "\u2007\u2007123")
        self.assertEqual(format(12.3, "\u2007>6"), "\u2007\u200712.3")
        self.assertEqual(format(1+2j, "\u2007>8"), "\u2007\u2007(1+2j)")
        self.assertEqual(format(0j, "\u2007>4"), "\u2007\u20070j")

        self.assertEqual(format("abc", "\u2007^5"), "\u2007abc\u2007")
        self.assertEqual(format(123, "\u2007^5"), "\u2007123\u2007")
        self.assertEqual(format(12.3, "\u2007^6"), "\u200712.3\u2007")
        self.assertEqual(format(1+2j, "\u2007^8"), "\u2007(1+2j)\u2007")
        self.assertEqual(format(0j, "\u2007^4"), "\u20070j\u2007")

    def test_locale(self):
        try:
            oldloc = locale.setlocale(locale.LC_ALL)
            locale.setlocale(locale.LC_ALL, '')
        except locale.Error as err:
            self.skipTest("Cannot set locale: {}".format(err))
        try:
            localeconv = locale.localeconv()
            sep = localeconv['thousands_sep']
            point = localeconv['decimal_point']

            text = format(123456789, "n")
            self.assertIn(sep, text)
            self.assertEqual(text.replace(sep, ''), '123456789')

            text = format(1234.5, "n")
            self.assertIn(sep, text)
            self.assertIn(point, text)
            self.assertEqual(text.replace(sep, ''), '1234' + point + '5')
        finally:
            locale.setlocale(locale.LC_ALL, oldloc)

    @support.cpython_only
    def test_optimisations(self):
        text = "abcde" # 5 characters

        self.assertIs("%s" % text, text)
        self.assertIs("%.5s" % text, text)
        self.assertIs("%.10s" % text, text)
        self.assertIs("%1s" % text, text)
        self.assertIs("%5s" % text, text)

        self.assertIs("{0}".format(text), text)
        self.assertIs("{0:s}".format(text), text)
        self.assertIs("{0:.5s}".format(text), text)
        self.assertIs("{0:.10s}".format(text), text)
        self.assertIs("{0:1s}".format(text), text)
        self.assertIs("{0:5s}".format(text), text)

        self.assertIs(text % (), text)
        self.assertIs(text.format(), text)

    def test_precision(self):
        f = 1.2
        self.assertEqual(format(f, ".0f"), "1")
        self.assertEqual(format(f, ".3f"), "1.200")
        with self.assertRaises(ValueError) as cm:
            format(f, ".%sf" % (sys.maxsize + 1))

        c = complex(f)
        self.assertEqual(format(c, ".0f"), "1+0j")
        self.assertEqual(format(c, ".3f"), "1.200+0.000j")
        with self.assertRaises(ValueError) as cm:
            format(c, ".%sf" % (sys.maxsize + 1))

    @support.cpython_only
    def test_precision_c_limits(self):
        from _testcapi import INT_MAX

        f = 1.2
        with self.assertRaises(ValueError) as cm:
            format(f, ".%sf" % (INT_MAX + 1))

        c = complex(f)
        with self.assertRaises(ValueError) as cm:
            format(c, ".%sf" % (INT_MAX + 1))


if __name__ == "__main__":
    unittest.main()