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1from test.support import verbose, TestFailed
2import locale
3import sys
4import re
5import test.support as support
6import unittest
7
8maxsize = support.MAX_Py_ssize_t
9
10# test string formatting operator (I am not sure if this is being tested
11# elsewhere but, surely, some of the given cases are *not* tested because
12# they crash python)
13# test on bytes object as well
14
15def testformat(formatstr, args, output=None, limit=None, overflowok=False):
16    if verbose:
17        if output:
18            print("{!a} % {!a} =? {!a} ...".format(formatstr, args, output),
19                  end=' ')
20        else:
21            print("{!a} % {!a} works? ...".format(formatstr, args), end=' ')
22    try:
23        result = formatstr % args
24    except OverflowError:
25        if not overflowok:
26            raise
27        if verbose:
28            print('overflow (this is fine)')
29    else:
30        if output and limit is None and result != output:
31            if verbose:
32                print('no')
33            raise AssertionError("%r %% %r == %r != %r" %
34                                (formatstr, args, result, output))
35        # when 'limit' is specified, it determines how many characters
36        # must match exactly; lengths must always match.
37        # ex: limit=5, '12345678' matches '12345___'
38        # (mainly for floating point format tests for which an exact match
39        # can't be guaranteed due to rounding and representation errors)
40        elif output and limit is not None and (
41                len(result)!=len(output) or result[:limit]!=output[:limit]):
42            if verbose:
43                print('no')
44            print("%s %% %s == %s != %s" % \
45                  (repr(formatstr), repr(args), repr(result), repr(output)))
46        else:
47            if verbose:
48                print('yes')
49
50def testcommon(formatstr, args, output=None, limit=None, overflowok=False):
51    # if formatstr is a str, test str, bytes, and bytearray;
52    # otherwise, test bytes and bytearray
53    if isinstance(formatstr, str):
54        testformat(formatstr, args, output, limit, overflowok)
55        b_format = formatstr.encode('ascii')
56    else:
57        b_format = formatstr
58    ba_format = bytearray(b_format)
59    b_args = []
60    if not isinstance(args, tuple):
61        args = (args, )
62    b_args = tuple(args)
63    if output is None:
64        b_output = ba_output = None
65    else:
66        if isinstance(output, str):
67            b_output = output.encode('ascii')
68        else:
69            b_output = output
70        ba_output = bytearray(b_output)
71    testformat(b_format, b_args, b_output, limit, overflowok)
72    testformat(ba_format, b_args, ba_output, limit, overflowok)
73
74def test_exc(formatstr, args, exception, excmsg):
75    try:
76        testformat(formatstr, args)
77    except exception as exc:
78        if str(exc) == excmsg:
79            if verbose:
80                print("yes")
81        else:
82            if verbose: print('no')
83            print('Unexpected ', exception, ':', repr(str(exc)))
84    except:
85        if verbose: print('no')
86        print('Unexpected exception')
87        raise
88    else:
89        raise TestFailed('did not get expected exception: %s' % excmsg)
90
91def test_exc_common(formatstr, args, exception, excmsg):
92    # test str and bytes
93    test_exc(formatstr, args, exception, excmsg)
94    test_exc(formatstr.encode('ascii'), args, exception, excmsg)
95
96class FormatTest(unittest.TestCase):
97
98    def test_common_format(self):
99        # test the format identifiers that work the same across
100        # str, bytes, and bytearrays (integer, float, oct, hex)
101        testcommon("%%", (), "%")
102        testcommon("%.1d", (1,), "1")
103        testcommon("%.*d", (sys.maxsize,1), overflowok=True)  # expect overflow
104        testcommon("%.100d", (1,), '00000000000000000000000000000000000000'
105                 '000000000000000000000000000000000000000000000000000000'
106                 '00000001', overflowok=True)
107        testcommon("%#.117x", (1,), '0x00000000000000000000000000000000000'
108                 '000000000000000000000000000000000000000000000000000000'
109                 '0000000000000000000000000001',
110                 overflowok=True)
111        testcommon("%#.118x", (1,), '0x00000000000000000000000000000000000'
112                 '000000000000000000000000000000000000000000000000000000'
113                 '00000000000000000000000000001',
114                 overflowok=True)
115
116        testcommon("%f", (1.0,), "1.000000")
117        # these are trying to test the limits of the internal magic-number-length
118        # formatting buffer, if that number changes then these tests are less
119        # effective
120        testcommon("%#.*g", (109, -1.e+49/3.))
121        testcommon("%#.*g", (110, -1.e+49/3.))
122        testcommon("%#.*g", (110, -1.e+100/3.))
123        # test some ridiculously large precision, expect overflow
124        testcommon('%12.*f', (123456, 1.0))
125
126        # check for internal overflow validation on length of precision
127        # these tests should no longer cause overflow in Python
128        # 2.7/3.1 and later.
129        testcommon("%#.*g", (110, -1.e+100/3.))
130        testcommon("%#.*G", (110, -1.e+100/3.))
131        testcommon("%#.*f", (110, -1.e+100/3.))
132        testcommon("%#.*F", (110, -1.e+100/3.))
133        # Formatting of integers. Overflow is not ok
134        testcommon("%x", 10, "a")
135        testcommon("%x", 100000000000, "174876e800")
136        testcommon("%o", 10, "12")
137        testcommon("%o", 100000000000, "1351035564000")
138        testcommon("%d", 10, "10")
139        testcommon("%d", 100000000000, "100000000000")
140
141        big = 123456789012345678901234567890
142        testcommon("%d", big, "123456789012345678901234567890")
143        testcommon("%d", -big, "-123456789012345678901234567890")
144        testcommon("%5d", -big, "-123456789012345678901234567890")
145        testcommon("%31d", -big, "-123456789012345678901234567890")
146        testcommon("%32d", -big, " -123456789012345678901234567890")
147        testcommon("%-32d", -big, "-123456789012345678901234567890 ")
148        testcommon("%032d", -big, "-0123456789012345678901234567890")
149        testcommon("%-032d", -big, "-123456789012345678901234567890 ")
150        testcommon("%034d", -big, "-000123456789012345678901234567890")
151        testcommon("%034d", big, "0000123456789012345678901234567890")
152        testcommon("%0+34d", big, "+000123456789012345678901234567890")
153        testcommon("%+34d", big, "   +123456789012345678901234567890")
154        testcommon("%34d", big, "    123456789012345678901234567890")
155        testcommon("%.2d", big, "123456789012345678901234567890")
156        testcommon("%.30d", big, "123456789012345678901234567890")
157        testcommon("%.31d", big, "0123456789012345678901234567890")
158        testcommon("%32.31d", big, " 0123456789012345678901234567890")
159        testcommon("%d", float(big), "123456________________________", 6)
160
161        big = 0x1234567890abcdef12345  # 21 hex digits
162        testcommon("%x", big, "1234567890abcdef12345")
163        testcommon("%x", -big, "-1234567890abcdef12345")
164        testcommon("%5x", -big, "-1234567890abcdef12345")
165        testcommon("%22x", -big, "-1234567890abcdef12345")
166        testcommon("%23x", -big, " -1234567890abcdef12345")
167        testcommon("%-23x", -big, "-1234567890abcdef12345 ")
168        testcommon("%023x", -big, "-01234567890abcdef12345")
169        testcommon("%-023x", -big, "-1234567890abcdef12345 ")
170        testcommon("%025x", -big, "-0001234567890abcdef12345")
171        testcommon("%025x", big, "00001234567890abcdef12345")
172        testcommon("%0+25x", big, "+0001234567890abcdef12345")
173        testcommon("%+25x", big, "   +1234567890abcdef12345")
174        testcommon("%25x", big, "    1234567890abcdef12345")
175        testcommon("%.2x", big, "1234567890abcdef12345")
176        testcommon("%.21x", big, "1234567890abcdef12345")
177        testcommon("%.22x", big, "01234567890abcdef12345")
178        testcommon("%23.22x", big, " 01234567890abcdef12345")
179        testcommon("%-23.22x", big, "01234567890abcdef12345 ")
180        testcommon("%X", big, "1234567890ABCDEF12345")
181        testcommon("%#X", big, "0X1234567890ABCDEF12345")
182        testcommon("%#x", big, "0x1234567890abcdef12345")
183        testcommon("%#x", -big, "-0x1234567890abcdef12345")
184        testcommon("%#27x", big, "    0x1234567890abcdef12345")
185        testcommon("%#-27x", big, "0x1234567890abcdef12345    ")
186        testcommon("%#027x", big, "0x00001234567890abcdef12345")
187        testcommon("%#.23x", big, "0x001234567890abcdef12345")
188        testcommon("%#.23x", -big, "-0x001234567890abcdef12345")
189        testcommon("%#27.23x", big, "  0x001234567890abcdef12345")
190        testcommon("%#-27.23x", big, "0x001234567890abcdef12345  ")
191        testcommon("%#027.23x", big, "0x00001234567890abcdef12345")
192        testcommon("%#+.23x", big, "+0x001234567890abcdef12345")
193        testcommon("%# .23x", big, " 0x001234567890abcdef12345")
194        testcommon("%#+.23X", big, "+0X001234567890ABCDEF12345")
195        # next one gets two leading zeroes from precision, and another from the
196        # 0 flag and the width
197        testcommon("%#+027.23X", big, "+0X0001234567890ABCDEF12345")
198        testcommon("%# 027.23X", big, " 0X0001234567890ABCDEF12345")
199        # same, except no 0 flag
200        testcommon("%#+27.23X", big, " +0X001234567890ABCDEF12345")
201        testcommon("%#-+27.23x", big, "+0x001234567890abcdef12345 ")
202        testcommon("%#- 27.23x", big, " 0x001234567890abcdef12345 ")
203
204        big = 0o12345670123456701234567012345670  # 32 octal digits
205        testcommon("%o", big, "12345670123456701234567012345670")
206        testcommon("%o", -big, "-12345670123456701234567012345670")
207        testcommon("%5o", -big, "-12345670123456701234567012345670")
208        testcommon("%33o", -big, "-12345670123456701234567012345670")
209        testcommon("%34o", -big, " -12345670123456701234567012345670")
210        testcommon("%-34o", -big, "-12345670123456701234567012345670 ")
211        testcommon("%034o", -big, "-012345670123456701234567012345670")
212        testcommon("%-034o", -big, "-12345670123456701234567012345670 ")
213        testcommon("%036o", -big, "-00012345670123456701234567012345670")
214        testcommon("%036o", big, "000012345670123456701234567012345670")
215        testcommon("%0+36o", big, "+00012345670123456701234567012345670")
216        testcommon("%+36o", big, "   +12345670123456701234567012345670")
217        testcommon("%36o", big, "    12345670123456701234567012345670")
218        testcommon("%.2o", big, "12345670123456701234567012345670")
219        testcommon("%.32o", big, "12345670123456701234567012345670")
220        testcommon("%.33o", big, "012345670123456701234567012345670")
221        testcommon("%34.33o", big, " 012345670123456701234567012345670")
222        testcommon("%-34.33o", big, "012345670123456701234567012345670 ")
223        testcommon("%o", big, "12345670123456701234567012345670")
224        testcommon("%#o", big, "0o12345670123456701234567012345670")
225        testcommon("%#o", -big, "-0o12345670123456701234567012345670")
226        testcommon("%#38o", big, "    0o12345670123456701234567012345670")
227        testcommon("%#-38o", big, "0o12345670123456701234567012345670    ")
228        testcommon("%#038o", big, "0o000012345670123456701234567012345670")
229        testcommon("%#.34o", big, "0o0012345670123456701234567012345670")
230        testcommon("%#.34o", -big, "-0o0012345670123456701234567012345670")
231        testcommon("%#38.34o", big, "  0o0012345670123456701234567012345670")
232        testcommon("%#-38.34o", big, "0o0012345670123456701234567012345670  ")
233        testcommon("%#038.34o", big, "0o000012345670123456701234567012345670")
234        testcommon("%#+.34o", big, "+0o0012345670123456701234567012345670")
235        testcommon("%# .34o", big, " 0o0012345670123456701234567012345670")
236        testcommon("%#+38.34o", big, " +0o0012345670123456701234567012345670")
237        testcommon("%#-+38.34o", big, "+0o0012345670123456701234567012345670 ")
238        testcommon("%#- 38.34o", big, " 0o0012345670123456701234567012345670 ")
239        testcommon("%#+038.34o", big, "+0o00012345670123456701234567012345670")
240        testcommon("%# 038.34o", big, " 0o00012345670123456701234567012345670")
241        # next one gets one leading zero from precision
242        testcommon("%.33o", big, "012345670123456701234567012345670")
243        # base marker added in spite of leading zero (different to Python 2)
244        testcommon("%#.33o", big, "0o012345670123456701234567012345670")
245        # reduce precision, and base marker is always added
246        testcommon("%#.32o", big, "0o12345670123456701234567012345670")
247        # one leading zero from precision, plus two from "0" flag & width
248        testcommon("%035.33o", big, "00012345670123456701234567012345670")
249        # base marker shouldn't change the size
250        testcommon("%0#35.33o", big, "0o012345670123456701234567012345670")
251
252        # Some small ints, in both Python int and flavors).
253        testcommon("%d", 42, "42")
254        testcommon("%d", -42, "-42")
255        testcommon("%d", 42.0, "42")
256        testcommon("%#x", 1, "0x1")
257        testcommon("%#X", 1, "0X1")
258        testcommon("%#o", 1, "0o1")
259        testcommon("%#o", 0, "0o0")
260        testcommon("%o", 0, "0")
261        testcommon("%d", 0, "0")
262        testcommon("%#x", 0, "0x0")
263        testcommon("%#X", 0, "0X0")
264        testcommon("%x", 0x42, "42")
265        testcommon("%x", -0x42, "-42")
266        testcommon("%o", 0o42, "42")
267        testcommon("%o", -0o42, "-42")
268        # alternate float formatting
269        testcommon('%g', 1.1, '1.1')
270        testcommon('%#g', 1.1, '1.10000')
271
272        if verbose:
273            print('Testing exceptions')
274        test_exc_common('%', (), ValueError, "incomplete format")
275        test_exc_common('% %s', 1, ValueError,
276                        "unsupported format character '%' (0x25) at index 2")
277        test_exc_common('%d', '1', TypeError,
278                        "%d format: a number is required, not str")
279        test_exc_common('%d', b'1', TypeError,
280                        "%d format: a number is required, not bytes")
281        test_exc_common('%x', '1', TypeError,
282                        "%x format: an integer is required, not str")
283        test_exc_common('%x', 3.14, TypeError,
284                        "%x format: an integer is required, not float")
285
286    def test_str_format(self):
287        testformat("%r", "\u0378", "'\\u0378'")  # non printable
288        testformat("%a", "\u0378", "'\\u0378'")  # non printable
289        testformat("%r", "\u0374", "'\u0374'")   # printable
290        testformat("%a", "\u0374", "'\\u0374'")  # printable
291
292        # Test exception for unknown format characters, etc.
293        if verbose:
294            print('Testing exceptions')
295        test_exc('abc %b', 1, ValueError,
296                 "unsupported format character 'b' (0x62) at index 5")
297        #test_exc(unicode('abc %\u3000','raw-unicode-escape'), 1, ValueError,
298        #         "unsupported format character '?' (0x3000) at index 5")
299        test_exc('%g', '1', TypeError, "must be real number, not str")
300        test_exc('no format', '1', TypeError,
301                 "not all arguments converted during string formatting")
302        test_exc('%c', -1, OverflowError, "%c arg not in range(0x110000)")
303        test_exc('%c', sys.maxunicode+1, OverflowError,
304                 "%c arg not in range(0x110000)")
305        #test_exc('%c', 2**128, OverflowError, "%c arg not in range(0x110000)")
306        test_exc('%c', 3.14, TypeError, "%c requires int or char")
307        test_exc('%c', 'ab', TypeError, "%c requires int or char")
308        test_exc('%c', b'x', TypeError, "%c requires int or char")
309
310        if maxsize == 2**31-1:
311            # crashes 2.2.1 and earlier:
312            try:
313                "%*d"%(maxsize, -127)
314            except MemoryError:
315                pass
316            else:
317                raise TestFailed('"%*d"%(maxsize, -127) should fail')
318
319    def test_bytes_and_bytearray_format(self):
320        # %c will insert a single byte, either from an int in range(256), or
321        # from a bytes argument of length 1, not from a str.
322        testcommon(b"%c", 7, b"\x07")
323        testcommon(b"%c", b"Z", b"Z")
324        testcommon(b"%c", bytearray(b"Z"), b"Z")
325        testcommon(b"%5c", 65, b"    A")
326        testcommon(b"%-5c", 65, b"A    ")
327        # %b will insert a series of bytes, either from a type that supports
328        # the Py_buffer protocol, or something that has a __bytes__ method
329        class FakeBytes(object):
330            def __bytes__(self):
331                return b'123'
332        fb = FakeBytes()
333        testcommon(b"%b", b"abc", b"abc")
334        testcommon(b"%b", bytearray(b"def"), b"def")
335        testcommon(b"%b", fb, b"123")
336        testcommon(b"%b", memoryview(b"abc"), b"abc")
337        # # %s is an alias for %b -- should only be used for Py2/3 code
338        testcommon(b"%s", b"abc", b"abc")
339        testcommon(b"%s", bytearray(b"def"), b"def")
340        testcommon(b"%s", fb, b"123")
341        testcommon(b"%s", memoryview(b"abc"), b"abc")
342        # %a will give the equivalent of
343        # repr(some_obj).encode('ascii', 'backslashreplace')
344        testcommon(b"%a", 3.14, b"3.14")
345        testcommon(b"%a", b"ghi", b"b'ghi'")
346        testcommon(b"%a", "jkl", b"'jkl'")
347        testcommon(b"%a", "\u0544", b"'\\u0544'")
348        # %r is an alias for %a
349        testcommon(b"%r", 3.14, b"3.14")
350        testcommon(b"%r", b"ghi", b"b'ghi'")
351        testcommon(b"%r", "jkl", b"'jkl'")
352        testcommon(b"%r", "\u0544", b"'\\u0544'")
353
354        # Test exception for unknown format characters, etc.
355        if verbose:
356            print('Testing exceptions')
357        test_exc(b'%g', '1', TypeError, "float argument required, not str")
358        test_exc(b'%g', b'1', TypeError, "float argument required, not bytes")
359        test_exc(b'no format', 7, TypeError,
360                 "not all arguments converted during bytes formatting")
361        test_exc(b'no format', b'1', TypeError,
362                 "not all arguments converted during bytes formatting")
363        test_exc(b'no format', bytearray(b'1'), TypeError,
364                 "not all arguments converted during bytes formatting")
365        test_exc(b"%c", -1, OverflowError,
366                "%c arg not in range(256)")
367        test_exc(b"%c", 256, OverflowError,
368                "%c arg not in range(256)")
369        test_exc(b"%c", 2**128, OverflowError,
370                "%c arg not in range(256)")
371        test_exc(b"%c", b"Za", TypeError,
372                "%c requires an integer in range(256) or a single byte")
373        test_exc(b"%c", "Y", TypeError,
374                "%c requires an integer in range(256) or a single byte")
375        test_exc(b"%c", 3.14, TypeError,
376                "%c requires an integer in range(256) or a single byte")
377        test_exc(b"%b", "Xc", TypeError,
378                "%b requires a bytes-like object, "
379                 "or an object that implements __bytes__, not 'str'")
380        test_exc(b"%s", "Wd", TypeError,
381                "%b requires a bytes-like object, "
382                 "or an object that implements __bytes__, not 'str'")
383
384        if maxsize == 2**31-1:
385            # crashes 2.2.1 and earlier:
386            try:
387                "%*d"%(maxsize, -127)
388            except MemoryError:
389                pass
390            else:
391                raise TestFailed('"%*d"%(maxsize, -127) should fail')
392
393    def test_nul(self):
394        # test the null character
395        testcommon("a\0b", (), 'a\0b')
396        testcommon("a%cb", (0,), 'a\0b')
397        testformat("a%sb", ('c\0d',), 'ac\0db')
398        testcommon(b"a%sb", (b'c\0d',), b'ac\0db')
399
400    def test_non_ascii(self):
401        testformat("\u20ac=%f", (1.0,), "\u20ac=1.000000")
402
403        self.assertEqual(format("abc", "\u2007<5"), "abc\u2007\u2007")
404        self.assertEqual(format(123, "\u2007<5"), "123\u2007\u2007")
405        self.assertEqual(format(12.3, "\u2007<6"), "12.3\u2007\u2007")
406        self.assertEqual(format(0j, "\u2007<4"), "0j\u2007\u2007")
407        self.assertEqual(format(1+2j, "\u2007<8"), "(1+2j)\u2007\u2007")
408
409        self.assertEqual(format("abc", "\u2007>5"), "\u2007\u2007abc")
410        self.assertEqual(format(123, "\u2007>5"), "\u2007\u2007123")
411        self.assertEqual(format(12.3, "\u2007>6"), "\u2007\u200712.3")
412        self.assertEqual(format(1+2j, "\u2007>8"), "\u2007\u2007(1+2j)")
413        self.assertEqual(format(0j, "\u2007>4"), "\u2007\u20070j")
414
415        self.assertEqual(format("abc", "\u2007^5"), "\u2007abc\u2007")
416        self.assertEqual(format(123, "\u2007^5"), "\u2007123\u2007")
417        self.assertEqual(format(12.3, "\u2007^6"), "\u200712.3\u2007")
418        self.assertEqual(format(1+2j, "\u2007^8"), "\u2007(1+2j)\u2007")
419        self.assertEqual(format(0j, "\u2007^4"), "\u20070j\u2007")
420
421    def test_locale(self):
422        try:
423            oldloc = locale.setlocale(locale.LC_ALL)
424            locale.setlocale(locale.LC_ALL, '')
425        except locale.Error as err:
426            self.skipTest("Cannot set locale: {}".format(err))
427        try:
428            localeconv = locale.localeconv()
429            sep = localeconv['thousands_sep']
430            point = localeconv['decimal_point']
431            grouping = localeconv['grouping']
432
433            text = format(123456789, "n")
434            if grouping:
435                self.assertIn(sep, text)
436            self.assertEqual(text.replace(sep, ''), '123456789')
437
438            text = format(1234.5, "n")
439            if grouping:
440                self.assertIn(sep, text)
441            self.assertIn(point, text)
442            self.assertEqual(text.replace(sep, ''), '1234' + point + '5')
443        finally:
444            locale.setlocale(locale.LC_ALL, oldloc)
445
446    @support.cpython_only
447    def test_optimisations(self):
448        text = "abcde" # 5 characters
449
450        self.assertIs("%s" % text, text)
451        self.assertIs("%.5s" % text, text)
452        self.assertIs("%.10s" % text, text)
453        self.assertIs("%1s" % text, text)
454        self.assertIs("%5s" % text, text)
455
456        self.assertIs("{0}".format(text), text)
457        self.assertIs("{0:s}".format(text), text)
458        self.assertIs("{0:.5s}".format(text), text)
459        self.assertIs("{0:.10s}".format(text), text)
460        self.assertIs("{0:1s}".format(text), text)
461        self.assertIs("{0:5s}".format(text), text)
462
463        self.assertIs(text % (), text)
464        self.assertIs(text.format(), text)
465
466    def test_precision(self):
467        f = 1.2
468        self.assertEqual(format(f, ".0f"), "1")
469        self.assertEqual(format(f, ".3f"), "1.200")
470        with self.assertRaises(ValueError) as cm:
471            format(f, ".%sf" % (sys.maxsize + 1))
472
473        c = complex(f)
474        self.assertEqual(format(c, ".0f"), "1+0j")
475        self.assertEqual(format(c, ".3f"), "1.200+0.000j")
476        with self.assertRaises(ValueError) as cm:
477            format(c, ".%sf" % (sys.maxsize + 1))
478
479    @support.cpython_only
480    def test_precision_c_limits(self):
481        from _testcapi import INT_MAX
482
483        f = 1.2
484        with self.assertRaises(ValueError) as cm:
485            format(f, ".%sf" % (INT_MAX + 1))
486
487        c = complex(f)
488        with self.assertRaises(ValueError) as cm:
489            format(c, ".%sf" % (INT_MAX + 1))
490
491    def test_g_format_has_no_trailing_zeros(self):
492        # regression test for bugs.python.org/issue40780
493        self.assertEqual("%.3g" % 1505.0, "1.5e+03")
494        self.assertEqual("%#.3g" % 1505.0, "1.50e+03")
495
496        self.assertEqual(format(1505.0, ".3g"), "1.5e+03")
497        self.assertEqual(format(1505.0, "#.3g"), "1.50e+03")
498
499        self.assertEqual(format(12300050.0, ".6g"), "1.23e+07")
500        self.assertEqual(format(12300050.0, "#.6g"), "1.23000e+07")
501
502    def test_with_two_commas_in_format_specifier(self):
503        error_msg = re.escape("Cannot specify ',' with ','.")
504        with self.assertRaisesRegex(ValueError, error_msg):
505            '{:,,}'.format(1)
506
507    def test_with_two_underscore_in_format_specifier(self):
508        error_msg = re.escape("Cannot specify '_' with '_'.")
509        with self.assertRaisesRegex(ValueError, error_msg):
510            '{:__}'.format(1)
511
512    def test_with_a_commas_and_an_underscore_in_format_specifier(self):
513        error_msg = re.escape("Cannot specify both ',' and '_'.")
514        with self.assertRaisesRegex(ValueError, error_msg):
515            '{:,_}'.format(1)
516
517    def test_with_an_underscore_and_a_comma_in_format_specifier(self):
518        error_msg = re.escape("Cannot specify both ',' and '_'.")
519        with self.assertRaisesRegex(ValueError, error_msg):
520            '{:_,}'.format(1)
521
522if __name__ == "__main__":
523    unittest.main()
524