Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 1 | import ast |
| 2 | import types |
| 3 | import decimal |
| 4 | import unittest |
| 5 | |
| 6 | a_global = 'global variable' |
| 7 | |
| 8 | # You could argue that I'm too strict in looking for specific error |
| 9 | # values with assertRaisesRegex, but without it it's way too easy to |
| 10 | # make a syntax error in the test strings. Especially with all of the |
| 11 | # triple quotes, raw strings, backslashes, etc. I think it's a |
| 12 | # worthwhile tradeoff. When I switched to this method, I found many |
| 13 | # examples where I wasn't testing what I thought I was. |
| 14 | |
| 15 | class TestCase(unittest.TestCase): |
| 16 | def assertAllRaise(self, exception_type, regex, error_strings): |
| 17 | for str in error_strings: |
| 18 | with self.subTest(str=str): |
| 19 | with self.assertRaisesRegex(exception_type, regex): |
| 20 | eval(str) |
| 21 | |
| 22 | def test__format__lookup(self): |
| 23 | # Make sure __format__ is looked up on the type, not the instance. |
| 24 | class X: |
| 25 | def __format__(self, spec): |
| 26 | return 'class' |
| 27 | |
| 28 | x = X() |
| 29 | |
| 30 | # Add a bound __format__ method to the 'y' instance, but not |
| 31 | # the 'x' instance. |
| 32 | y = X() |
| 33 | y.__format__ = types.MethodType(lambda self, spec: 'instance', y) |
| 34 | |
| 35 | self.assertEqual(f'{y}', format(y)) |
| 36 | self.assertEqual(f'{y}', 'class') |
| 37 | self.assertEqual(format(x), format(y)) |
| 38 | |
| 39 | # __format__ is not called this way, but still make sure it |
| 40 | # returns what we expect (so we can make sure we're bypassing |
| 41 | # it). |
| 42 | self.assertEqual(x.__format__(''), 'class') |
| 43 | self.assertEqual(y.__format__(''), 'instance') |
| 44 | |
| 45 | # This is how __format__ is actually called. |
| 46 | self.assertEqual(type(x).__format__(x, ''), 'class') |
| 47 | self.assertEqual(type(y).__format__(y, ''), 'class') |
| 48 | |
| 49 | def test_ast(self): |
| 50 | # Inspired by http://bugs.python.org/issue24975 |
| 51 | class X: |
| 52 | def __init__(self): |
| 53 | self.called = False |
| 54 | def __call__(self): |
| 55 | self.called = True |
| 56 | return 4 |
| 57 | x = X() |
| 58 | expr = """ |
| 59 | a = 10 |
| 60 | f'{a * x()}'""" |
| 61 | t = ast.parse(expr) |
| 62 | c = compile(t, '', 'exec') |
| 63 | |
| 64 | # Make sure x was not called. |
| 65 | self.assertFalse(x.called) |
| 66 | |
| 67 | # Actually run the code. |
| 68 | exec(c) |
| 69 | |
| 70 | # Make sure x was called. |
| 71 | self.assertTrue(x.called) |
| 72 | |
| 73 | def test_literal_eval(self): |
| 74 | # With no expressions, an f-string is okay. |
| 75 | self.assertEqual(ast.literal_eval("f'x'"), 'x') |
| 76 | self.assertEqual(ast.literal_eval("f'x' 'y'"), 'xy') |
| 77 | |
| 78 | # But this should raise an error. |
| 79 | with self.assertRaisesRegex(ValueError, 'malformed node or string'): |
| 80 | ast.literal_eval("f'x{3}'") |
| 81 | |
| 82 | # As should this, which uses a different ast node |
| 83 | with self.assertRaisesRegex(ValueError, 'malformed node or string'): |
| 84 | ast.literal_eval("f'{3}'") |
| 85 | |
| 86 | def test_ast_compile_time_concat(self): |
| 87 | x = [''] |
| 88 | |
| 89 | expr = """x[0] = 'foo' f'{3}'""" |
| 90 | t = ast.parse(expr) |
| 91 | c = compile(t, '', 'exec') |
| 92 | exec(c) |
| 93 | self.assertEqual(x[0], 'foo3') |
| 94 | |
| 95 | def test_literal(self): |
| 96 | self.assertEqual(f'', '') |
| 97 | self.assertEqual(f'a', 'a') |
| 98 | self.assertEqual(f' ', ' ') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 99 | |
| 100 | def test_unterminated_string(self): |
| 101 | self.assertAllRaise(SyntaxError, 'f-string: unterminated string', |
| 102 | [r"""f'{"x'""", |
| 103 | r"""f'{"x}'""", |
| 104 | r"""f'{("x'""", |
| 105 | r"""f'{("x}'""", |
| 106 | ]) |
| 107 | |
| 108 | def test_mismatched_parens(self): |
| 109 | self.assertAllRaise(SyntaxError, 'f-string: mismatched', |
| 110 | ["f'{((}'", |
| 111 | ]) |
| 112 | |
| 113 | def test_double_braces(self): |
| 114 | self.assertEqual(f'{{', '{') |
| 115 | self.assertEqual(f'a{{', 'a{') |
| 116 | self.assertEqual(f'{{b', '{b') |
| 117 | self.assertEqual(f'a{{b', 'a{b') |
| 118 | self.assertEqual(f'}}', '}') |
| 119 | self.assertEqual(f'a}}', 'a}') |
| 120 | self.assertEqual(f'}}b', '}b') |
| 121 | self.assertEqual(f'a}}b', 'a}b') |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 122 | self.assertEqual(f'{{}}', '{}') |
| 123 | self.assertEqual(f'a{{}}', 'a{}') |
| 124 | self.assertEqual(f'{{b}}', '{b}') |
| 125 | self.assertEqual(f'{{}}c', '{}c') |
| 126 | self.assertEqual(f'a{{b}}', 'a{b}') |
| 127 | self.assertEqual(f'a{{}}c', 'a{}c') |
| 128 | self.assertEqual(f'{{b}}c', '{b}c') |
| 129 | self.assertEqual(f'a{{b}}c', 'a{b}c') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 130 | |
| 131 | self.assertEqual(f'{{{10}', '{10') |
| 132 | self.assertEqual(f'}}{10}', '}10') |
| 133 | self.assertEqual(f'}}{{{10}', '}{10') |
| 134 | self.assertEqual(f'}}a{{{10}', '}a{10') |
| 135 | |
| 136 | self.assertEqual(f'{10}{{', '10{') |
| 137 | self.assertEqual(f'{10}}}', '10}') |
| 138 | self.assertEqual(f'{10}}}{{', '10}{') |
| 139 | self.assertEqual(f'{10}}}a{{' '}', '10}a{}') |
| 140 | |
| 141 | # Inside of strings, don't interpret doubled brackets. |
| 142 | self.assertEqual(f'{"{{}}"}', '{{}}') |
| 143 | |
| 144 | self.assertAllRaise(TypeError, 'unhashable type', |
| 145 | ["f'{ {{}} }'", # dict in a set |
| 146 | ]) |
| 147 | |
| 148 | def test_compile_time_concat(self): |
| 149 | x = 'def' |
| 150 | self.assertEqual('abc' f'## {x}ghi', 'abc## defghi') |
| 151 | self.assertEqual('abc' f'{x}' 'ghi', 'abcdefghi') |
| 152 | self.assertEqual('abc' f'{x}' 'gh' f'i{x:4}', 'abcdefghidef ') |
| 153 | self.assertEqual('{x}' f'{x}', '{x}def') |
| 154 | self.assertEqual('{x' f'{x}', '{xdef') |
| 155 | self.assertEqual('{x}' f'{x}', '{x}def') |
| 156 | self.assertEqual('{{x}}' f'{x}', '{{x}}def') |
| 157 | self.assertEqual('{{x' f'{x}', '{{xdef') |
| 158 | self.assertEqual('x}}' f'{x}', 'x}}def') |
| 159 | self.assertEqual(f'{x}' 'x}}', 'defx}}') |
| 160 | self.assertEqual(f'{x}' '', 'def') |
| 161 | self.assertEqual('' f'{x}' '', 'def') |
| 162 | self.assertEqual('' f'{x}', 'def') |
| 163 | self.assertEqual(f'{x}' '2', 'def2') |
| 164 | self.assertEqual('1' f'{x}' '2', '1def2') |
| 165 | self.assertEqual('1' f'{x}', '1def') |
| 166 | self.assertEqual(f'{x}' f'-{x}', 'def-def') |
| 167 | self.assertEqual('' f'', '') |
| 168 | self.assertEqual('' f'' '', '') |
| 169 | self.assertEqual('' f'' '' f'', '') |
| 170 | self.assertEqual(f'', '') |
| 171 | self.assertEqual(f'' '', '') |
| 172 | self.assertEqual(f'' '' f'', '') |
| 173 | self.assertEqual(f'' '' f'' '', '') |
| 174 | |
| 175 | self.assertAllRaise(SyntaxError, "f-string: expecting '}'", |
| 176 | ["f'{3' f'}'", # can't concat to get a valid f-string |
| 177 | ]) |
| 178 | |
| 179 | def test_comments(self): |
| 180 | # These aren't comments, since they're in strings. |
| 181 | d = {'#': 'hash'} |
| 182 | self.assertEqual(f'{"#"}', '#') |
| 183 | self.assertEqual(f'{d["#"]}', 'hash') |
| 184 | |
Eric V. Smith | 09835dc | 2016-09-11 18:58:20 -0400 | [diff] [blame] | 185 | self.assertAllRaise(SyntaxError, "f-string expression part cannot include '#'", |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 186 | ["f'{1#}'", # error because the expression becomes "(1#)" |
| 187 | "f'{3(#)}'", |
Eric V. Smith | 09835dc | 2016-09-11 18:58:20 -0400 | [diff] [blame] | 188 | "f'{#}'", |
Eric V. Smith | 35a24c5 | 2016-09-11 19:01:22 -0400 | [diff] [blame] | 189 | "f'{)#}'", # When wrapped in parens, this becomes |
| 190 | # '()#)'. Make sure that doesn't compile. |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 191 | ]) |
| 192 | |
| 193 | def test_many_expressions(self): |
| 194 | # Create a string with many expressions in it. Note that |
| 195 | # because we have a space in here as a literal, we're actually |
| 196 | # going to use twice as many ast nodes: one for each literal |
| 197 | # plus one for each expression. |
| 198 | def build_fstr(n, extra=''): |
| 199 | return "f'" + ('{x} ' * n) + extra + "'" |
| 200 | |
| 201 | x = 'X' |
| 202 | width = 1 |
| 203 | |
| 204 | # Test around 256. |
| 205 | for i in range(250, 260): |
| 206 | self.assertEqual(eval(build_fstr(i)), (x+' ')*i) |
| 207 | |
| 208 | # Test concatenating 2 largs fstrings. |
| 209 | self.assertEqual(eval(build_fstr(255)*256), (x+' ')*(255*256)) |
| 210 | |
| 211 | s = build_fstr(253, '{x:{width}} ') |
| 212 | self.assertEqual(eval(s), (x+' ')*254) |
| 213 | |
| 214 | # Test lots of expressions and constants, concatenated. |
| 215 | s = "f'{1}' 'x' 'y'" * 1024 |
| 216 | self.assertEqual(eval(s), '1xy' * 1024) |
| 217 | |
| 218 | def test_format_specifier_expressions(self): |
| 219 | width = 10 |
| 220 | precision = 4 |
| 221 | value = decimal.Decimal('12.34567') |
| 222 | self.assertEqual(f'result: {value:{width}.{precision}}', 'result: 12.35') |
| 223 | self.assertEqual(f'result: {value:{width!r}.{precision}}', 'result: 12.35') |
| 224 | self.assertEqual(f'result: {value:{width:0}.{precision:1}}', 'result: 12.35') |
| 225 | self.assertEqual(f'result: {value:{1}{0:0}.{precision:1}}', 'result: 12.35') |
| 226 | self.assertEqual(f'result: {value:{ 1}{ 0:0}.{ precision:1}}', 'result: 12.35') |
| 227 | self.assertEqual(f'{10:#{1}0x}', ' 0xa') |
| 228 | self.assertEqual(f'{10:{"#"}1{0}{"x"}}', ' 0xa') |
| 229 | self.assertEqual(f'{-10:-{"#"}1{0}x}', ' -0xa') |
| 230 | self.assertEqual(f'{-10:{"-"}#{1}0{"x"}}', ' -0xa') |
| 231 | self.assertEqual(f'{10:#{3 != {4:5} and width}x}', ' 0xa') |
| 232 | |
| 233 | self.assertAllRaise(SyntaxError, "f-string: expecting '}'", |
| 234 | ["""f'{"s"!r{":10"}}'""", |
| 235 | |
| 236 | # This looks like a nested format spec. |
| 237 | ]) |
| 238 | |
| 239 | self.assertAllRaise(SyntaxError, "invalid syntax", |
Martin Panter | 263893c | 2016-07-28 01:25:31 +0000 | [diff] [blame] | 240 | [# Invalid syntax inside a nested spec. |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 241 | "f'{4:{/5}}'", |
| 242 | ]) |
| 243 | |
| 244 | self.assertAllRaise(SyntaxError, "f-string: expressions nested too deeply", |
| 245 | [# Can't nest format specifiers. |
| 246 | "f'result: {value:{width:{0}}.{precision:1}}'", |
| 247 | ]) |
| 248 | |
| 249 | self.assertAllRaise(SyntaxError, 'f-string: invalid conversion character', |
| 250 | [# No expansion inside conversion or for |
| 251 | # the : or ! itself. |
| 252 | """f'{"s"!{"r"}}'""", |
| 253 | ]) |
| 254 | |
| 255 | def test_side_effect_order(self): |
| 256 | class X: |
| 257 | def __init__(self): |
| 258 | self.i = 0 |
| 259 | def __format__(self, spec): |
| 260 | self.i += 1 |
| 261 | return str(self.i) |
| 262 | |
| 263 | x = X() |
| 264 | self.assertEqual(f'{x} {x}', '1 2') |
| 265 | |
| 266 | def test_missing_expression(self): |
| 267 | self.assertAllRaise(SyntaxError, 'f-string: empty expression not allowed', |
| 268 | ["f'{}'", |
| 269 | "f'{ }'" |
| 270 | "f' {} '", |
| 271 | "f'{!r}'", |
| 272 | "f'{ !r}'", |
| 273 | "f'{10:{ }}'", |
| 274 | "f' { } '", |
Eric V. Smith | 1d44c41 | 2015-09-23 07:49:00 -0400 | [diff] [blame] | 275 | |
| 276 | # Catch the empty expression before the |
| 277 | # invalid conversion. |
| 278 | "f'{!x}'", |
| 279 | "f'{ !xr}'", |
| 280 | "f'{!x:}'", |
| 281 | "f'{!x:a}'", |
| 282 | "f'{ !xr:}'", |
| 283 | "f'{ !xr:a}'", |
Eric V. Smith | 548c4d3 | 2015-09-23 08:00:01 -0400 | [diff] [blame] | 284 | |
| 285 | "f'{!}'", |
| 286 | "f'{:}'", |
Eric V. Smith | b2080f6 | 2015-09-23 10:24:43 -0400 | [diff] [blame] | 287 | |
| 288 | # We find the empty expression before the |
| 289 | # missing closing brace. |
| 290 | "f'{!'", |
| 291 | "f'{!s:'", |
| 292 | "f'{:'", |
| 293 | "f'{:x'", |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 294 | ]) |
| 295 | |
| 296 | def test_parens_in_expressions(self): |
| 297 | self.assertEqual(f'{3,}', '(3,)') |
| 298 | |
| 299 | # Add these because when an expression is evaluated, parens |
| 300 | # are added around it. But we shouldn't go from an invalid |
| 301 | # expression to a valid one. The added parens are just |
| 302 | # supposed to allow whitespace (including newlines). |
| 303 | self.assertAllRaise(SyntaxError, 'invalid syntax', |
| 304 | ["f'{,}'", |
| 305 | "f'{,}'", # this is (,), which is an error |
| 306 | ]) |
| 307 | |
| 308 | self.assertAllRaise(SyntaxError, "f-string: expecting '}'", |
| 309 | ["f'{3)+(4}'", |
| 310 | ]) |
| 311 | |
| 312 | self.assertAllRaise(SyntaxError, 'EOL while scanning string literal', |
| 313 | ["f'{\n}'", |
| 314 | ]) |
| 315 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 316 | def test_backslashes_in_string_part(self): |
| 317 | self.assertEqual(f'\t', '\t') |
| 318 | self.assertEqual(r'\t', '\\t') |
| 319 | self.assertEqual(rf'\t', '\\t') |
| 320 | self.assertEqual(f'{2}\t', '2\t') |
| 321 | self.assertEqual(f'{2}\t{3}', '2\t3') |
| 322 | self.assertEqual(f'\t{3}', '\t3') |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 323 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 324 | self.assertEqual(f'\u0394', '\u0394') |
| 325 | self.assertEqual(r'\u0394', '\\u0394') |
| 326 | self.assertEqual(rf'\u0394', '\\u0394') |
| 327 | self.assertEqual(f'{2}\u0394', '2\u0394') |
| 328 | self.assertEqual(f'{2}\u0394{3}', '2\u03943') |
| 329 | self.assertEqual(f'\u0394{3}', '\u03943') |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 330 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 331 | self.assertEqual(f'\U00000394', '\u0394') |
| 332 | self.assertEqual(r'\U00000394', '\\U00000394') |
| 333 | self.assertEqual(rf'\U00000394', '\\U00000394') |
| 334 | self.assertEqual(f'{2}\U00000394', '2\u0394') |
| 335 | self.assertEqual(f'{2}\U00000394{3}', '2\u03943') |
| 336 | self.assertEqual(f'\U00000394{3}', '\u03943') |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 337 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 338 | self.assertEqual(f'\N{GREEK CAPITAL LETTER DELTA}', '\u0394') |
| 339 | self.assertEqual(f'{2}\N{GREEK CAPITAL LETTER DELTA}', '2\u0394') |
| 340 | self.assertEqual(f'{2}\N{GREEK CAPITAL LETTER DELTA}{3}', '2\u03943') |
| 341 | self.assertEqual(f'\N{GREEK CAPITAL LETTER DELTA}{3}', '\u03943') |
| 342 | self.assertEqual(f'2\N{GREEK CAPITAL LETTER DELTA}', '2\u0394') |
| 343 | self.assertEqual(f'2\N{GREEK CAPITAL LETTER DELTA}3', '2\u03943') |
| 344 | self.assertEqual(f'\N{GREEK CAPITAL LETTER DELTA}3', '\u03943') |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 345 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 346 | self.assertEqual(f'\x20', ' ') |
| 347 | self.assertEqual(r'\x20', '\\x20') |
| 348 | self.assertEqual(rf'\x20', '\\x20') |
| 349 | self.assertEqual(f'{2}\x20', '2 ') |
| 350 | self.assertEqual(f'{2}\x20{3}', '2 3') |
| 351 | self.assertEqual(f'\x20{3}', ' 3') |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 352 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 353 | self.assertEqual(f'2\x20', '2 ') |
| 354 | self.assertEqual(f'2\x203', '2 3') |
| 355 | self.assertEqual(f'\x203', ' 3') |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 356 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 357 | def test_misformed_unicode_character_name(self): |
| 358 | # These test are needed because unicode names are parsed |
| 359 | # differently inside f-strings. |
| 360 | self.assertAllRaise(SyntaxError, r"\(unicode error\) 'unicodeescape' codec can't decode bytes in position .*: malformed \\N character escape", |
| 361 | [r"f'\N'", |
| 362 | r"f'\N{'", |
| 363 | r"f'\N{GREEK CAPITAL LETTER DELTA'", |
| 364 | |
| 365 | # Here are the non-f-string versions, |
| 366 | # which should give the same errors. |
| 367 | r"'\N'", |
| 368 | r"'\N{'", |
| 369 | r"'\N{GREEK CAPITAL LETTER DELTA'", |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 370 | ]) |
| 371 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 372 | def test_no_backslashes_in_expression_part(self): |
| 373 | self.assertAllRaise(SyntaxError, 'f-string expression part cannot include a backslash', |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 374 | [r"f'{\'a\'}'", |
| 375 | r"f'{\t3}'", |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 376 | r"f'{\}'", |
| 377 | r"rf'{\'a\'}'", |
| 378 | r"rf'{\t3}'", |
| 379 | r"rf'{\}'", |
| 380 | r"""rf'{"\N{LEFT CURLY BRACKET}"}'""", |
Jason R. Coombs | 45cab8c | 2016-11-06 11:01:08 -0500 | [diff] [blame^] | 381 | r"f'{\n}'", |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 382 | ]) |
| 383 | |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 384 | def test_no_escapes_for_braces(self): |
| 385 | # \x7b is '{'. Make sure it doesn't start an expression. |
| 386 | self.assertEqual(f'\x7b2}}', '{2}') |
| 387 | self.assertEqual(f'\x7b2', '{2') |
| 388 | self.assertEqual(f'\u007b2', '{2') |
| 389 | self.assertEqual(f'\N{LEFT CURLY BRACKET}2\N{RIGHT CURLY BRACKET}', '{2}') |
Eric V. Smith | 6a4efce | 2016-09-03 09:18:34 -0400 | [diff] [blame] | 390 | |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 391 | def test_newlines_in_expressions(self): |
| 392 | self.assertEqual(f'{0}', '0') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 393 | self.assertEqual(rf'''{3+ |
| 394 | 4}''', '7') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 395 | |
| 396 | def test_lambda(self): |
| 397 | x = 5 |
| 398 | self.assertEqual(f'{(lambda y:x*y)("8")!r}', "'88888'") |
| 399 | self.assertEqual(f'{(lambda y:x*y)("8")!r:10}', "'88888' ") |
| 400 | self.assertEqual(f'{(lambda y:x*y)("8"):10}', "88888 ") |
| 401 | |
| 402 | # lambda doesn't work without parens, because the colon |
| 403 | # makes the parser think it's a format_spec |
| 404 | self.assertAllRaise(SyntaxError, 'unexpected EOF while parsing', |
| 405 | ["f'{lambda x:x}'", |
| 406 | ]) |
| 407 | |
| 408 | def test_yield(self): |
| 409 | # Not terribly useful, but make sure the yield turns |
| 410 | # a function into a generator |
| 411 | def fn(y): |
| 412 | f'y:{yield y*2}' |
| 413 | |
| 414 | g = fn(4) |
| 415 | self.assertEqual(next(g), 8) |
| 416 | |
| 417 | def test_yield_send(self): |
| 418 | def fn(x): |
| 419 | yield f'x:{yield (lambda i: x * i)}' |
| 420 | |
| 421 | g = fn(10) |
| 422 | the_lambda = next(g) |
| 423 | self.assertEqual(the_lambda(4), 40) |
| 424 | self.assertEqual(g.send('string'), 'x:string') |
| 425 | |
| 426 | def test_expressions_with_triple_quoted_strings(self): |
| 427 | self.assertEqual(f"{'''x'''}", 'x') |
| 428 | self.assertEqual(f"{'''eric's'''}", "eric's") |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 429 | |
| 430 | # Test concatenation within an expression |
| 431 | self.assertEqual(f'{"x" """eric"s""" "y"}', 'xeric"sy') |
| 432 | self.assertEqual(f'{"x" """eric"s"""}', 'xeric"s') |
| 433 | self.assertEqual(f'{"""eric"s""" "y"}', 'eric"sy') |
| 434 | self.assertEqual(f'{"""x""" """eric"s""" "y"}', 'xeric"sy') |
| 435 | self.assertEqual(f'{"""x""" """eric"s""" """y"""}', 'xeric"sy') |
| 436 | self.assertEqual(f'{r"""x""" """eric"s""" """y"""}', 'xeric"sy') |
| 437 | |
| 438 | def test_multiple_vars(self): |
| 439 | x = 98 |
| 440 | y = 'abc' |
| 441 | self.assertEqual(f'{x}{y}', '98abc') |
| 442 | |
| 443 | self.assertEqual(f'X{x}{y}', 'X98abc') |
| 444 | self.assertEqual(f'{x}X{y}', '98Xabc') |
| 445 | self.assertEqual(f'{x}{y}X', '98abcX') |
| 446 | |
| 447 | self.assertEqual(f'X{x}Y{y}', 'X98Yabc') |
| 448 | self.assertEqual(f'X{x}{y}Y', 'X98abcY') |
| 449 | self.assertEqual(f'{x}X{y}Y', '98XabcY') |
| 450 | |
| 451 | self.assertEqual(f'X{x}Y{y}Z', 'X98YabcZ') |
| 452 | |
| 453 | def test_closure(self): |
| 454 | def outer(x): |
| 455 | def inner(): |
| 456 | return f'x:{x}' |
| 457 | return inner |
| 458 | |
| 459 | self.assertEqual(outer('987')(), 'x:987') |
| 460 | self.assertEqual(outer(7)(), 'x:7') |
| 461 | |
| 462 | def test_arguments(self): |
| 463 | y = 2 |
| 464 | def f(x, width): |
| 465 | return f'x={x*y:{width}}' |
| 466 | |
| 467 | self.assertEqual(f('foo', 10), 'x=foofoo ') |
| 468 | x = 'bar' |
| 469 | self.assertEqual(f(10, 10), 'x= 20') |
| 470 | |
| 471 | def test_locals(self): |
| 472 | value = 123 |
| 473 | self.assertEqual(f'v:{value}', 'v:123') |
| 474 | |
| 475 | def test_missing_variable(self): |
| 476 | with self.assertRaises(NameError): |
| 477 | f'v:{value}' |
| 478 | |
| 479 | def test_missing_format_spec(self): |
| 480 | class O: |
| 481 | def __format__(self, spec): |
| 482 | if not spec: |
| 483 | return '*' |
| 484 | return spec |
| 485 | |
| 486 | self.assertEqual(f'{O():x}', 'x') |
| 487 | self.assertEqual(f'{O()}', '*') |
| 488 | self.assertEqual(f'{O():}', '*') |
| 489 | |
| 490 | self.assertEqual(f'{3:}', '3') |
| 491 | self.assertEqual(f'{3!s:}', '3') |
| 492 | |
| 493 | def test_global(self): |
| 494 | self.assertEqual(f'g:{a_global}', 'g:global variable') |
| 495 | self.assertEqual(f'g:{a_global!r}', "g:'global variable'") |
| 496 | |
| 497 | a_local = 'local variable' |
| 498 | self.assertEqual(f'g:{a_global} l:{a_local}', |
| 499 | 'g:global variable l:local variable') |
| 500 | self.assertEqual(f'g:{a_global!r}', |
| 501 | "g:'global variable'") |
| 502 | self.assertEqual(f'g:{a_global} l:{a_local!r}', |
| 503 | "g:global variable l:'local variable'") |
| 504 | |
| 505 | self.assertIn("module 'unittest' from", f'{unittest}') |
| 506 | |
| 507 | def test_shadowed_global(self): |
| 508 | a_global = 'really a local' |
| 509 | self.assertEqual(f'g:{a_global}', 'g:really a local') |
| 510 | self.assertEqual(f'g:{a_global!r}', "g:'really a local'") |
| 511 | |
| 512 | a_local = 'local variable' |
| 513 | self.assertEqual(f'g:{a_global} l:{a_local}', |
| 514 | 'g:really a local l:local variable') |
| 515 | self.assertEqual(f'g:{a_global!r}', |
| 516 | "g:'really a local'") |
| 517 | self.assertEqual(f'g:{a_global} l:{a_local!r}', |
| 518 | "g:really a local l:'local variable'") |
| 519 | |
| 520 | def test_call(self): |
| 521 | def foo(x): |
| 522 | return 'x=' + str(x) |
| 523 | |
| 524 | self.assertEqual(f'{foo(10)}', 'x=10') |
| 525 | |
| 526 | def test_nested_fstrings(self): |
| 527 | y = 5 |
| 528 | self.assertEqual(f'{f"{0}"*3}', '000') |
| 529 | self.assertEqual(f'{f"{y}"*3}', '555') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 530 | |
| 531 | def test_invalid_string_prefixes(self): |
| 532 | self.assertAllRaise(SyntaxError, 'unexpected EOF while parsing', |
| 533 | ["fu''", |
| 534 | "uf''", |
| 535 | "Fu''", |
| 536 | "fU''", |
| 537 | "Uf''", |
| 538 | "uF''", |
| 539 | "ufr''", |
| 540 | "urf''", |
| 541 | "fur''", |
| 542 | "fru''", |
| 543 | "rfu''", |
| 544 | "ruf''", |
| 545 | "FUR''", |
| 546 | "Fur''", |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 547 | "fb''", |
| 548 | "fB''", |
| 549 | "Fb''", |
| 550 | "FB''", |
| 551 | "bf''", |
| 552 | "bF''", |
| 553 | "Bf''", |
| 554 | "BF''", |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 555 | ]) |
| 556 | |
| 557 | def test_leading_trailing_spaces(self): |
| 558 | self.assertEqual(f'{ 3}', '3') |
| 559 | self.assertEqual(f'{ 3}', '3') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 560 | self.assertEqual(f'{3 }', '3') |
| 561 | self.assertEqual(f'{3 }', '3') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 562 | |
| 563 | self.assertEqual(f'expr={ {x: y for x, y in [(1, 2), ]}}', |
| 564 | 'expr={1: 2}') |
| 565 | self.assertEqual(f'expr={ {x: y for x, y in [(1, 2), ]} }', |
| 566 | 'expr={1: 2}') |
| 567 | |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 568 | def test_not_equal(self): |
| 569 | # There's a special test for this because there's a special |
| 570 | # case in the f-string parser to look for != as not ending an |
| 571 | # expression. Normally it would, while looking for !s or !r. |
| 572 | |
| 573 | self.assertEqual(f'{3!=4}', 'True') |
| 574 | self.assertEqual(f'{3!=4:}', 'True') |
| 575 | self.assertEqual(f'{3!=4!s}', 'True') |
| 576 | self.assertEqual(f'{3!=4!s:.3}', 'Tru') |
| 577 | |
| 578 | def test_conversions(self): |
| 579 | self.assertEqual(f'{3.14:10.10}', ' 3.14') |
| 580 | self.assertEqual(f'{3.14!s:10.10}', '3.14 ') |
| 581 | self.assertEqual(f'{3.14!r:10.10}', '3.14 ') |
| 582 | self.assertEqual(f'{3.14!a:10.10}', '3.14 ') |
| 583 | |
| 584 | self.assertEqual(f'{"a"}', 'a') |
| 585 | self.assertEqual(f'{"a"!r}', "'a'") |
| 586 | self.assertEqual(f'{"a"!a}', "'a'") |
| 587 | |
| 588 | # Not a conversion. |
| 589 | self.assertEqual(f'{"a!r"}', "a!r") |
| 590 | |
| 591 | # Not a conversion, but show that ! is allowed in a format spec. |
| 592 | self.assertEqual(f'{3.14:!<10.10}', '3.14!!!!!!') |
| 593 | |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 594 | self.assertAllRaise(SyntaxError, 'f-string: invalid conversion character', |
| 595 | ["f'{3!g}'", |
| 596 | "f'{3!A}'", |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 597 | "f'{3!3}'", |
| 598 | "f'{3!G}'", |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 599 | "f'{3!!}'", |
| 600 | "f'{3!:}'", |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 601 | "f'{3! s}'", # no space before conversion char |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 602 | ]) |
| 603 | |
| 604 | self.assertAllRaise(SyntaxError, "f-string: expecting '}'", |
| 605 | ["f'{x!s{y}}'", |
| 606 | "f'{3!ss}'", |
| 607 | "f'{3!ss:}'", |
| 608 | "f'{3!ss:s}'", |
| 609 | ]) |
| 610 | |
| 611 | def test_assignment(self): |
| 612 | self.assertAllRaise(SyntaxError, 'invalid syntax', |
| 613 | ["f'' = 3", |
| 614 | "f'{0}' = x", |
| 615 | "f'{x}' = x", |
| 616 | ]) |
| 617 | |
| 618 | def test_del(self): |
| 619 | self.assertAllRaise(SyntaxError, 'invalid syntax', |
| 620 | ["del f''", |
| 621 | "del '' f''", |
| 622 | ]) |
| 623 | |
| 624 | def test_mismatched_braces(self): |
| 625 | self.assertAllRaise(SyntaxError, "f-string: single '}' is not allowed", |
| 626 | ["f'{{}'", |
| 627 | "f'{{}}}'", |
| 628 | "f'}'", |
| 629 | "f'x}'", |
| 630 | "f'x}x'", |
| 631 | |
| 632 | # Can't have { or } in a format spec. |
| 633 | "f'{3:}>10}'", |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 634 | "f'{3:}}>10}'", |
| 635 | ]) |
| 636 | |
| 637 | self.assertAllRaise(SyntaxError, "f-string: expecting '}'", |
| 638 | ["f'{3:{{>10}'", |
| 639 | "f'{3'", |
| 640 | "f'{3!'", |
| 641 | "f'{3:'", |
| 642 | "f'{3!s'", |
| 643 | "f'{3!s:'", |
| 644 | "f'{3!s:3'", |
| 645 | "f'x{'", |
| 646 | "f'x{x'", |
Eric V. Smith | 451d0e3 | 2016-09-09 21:56:20 -0400 | [diff] [blame] | 647 | "f'{x'", |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 648 | "f'{3:s'", |
| 649 | "f'{{{'", |
| 650 | "f'{{}}{'", |
| 651 | "f'{'", |
| 652 | ]) |
| 653 | |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 654 | # But these are just normal strings. |
| 655 | self.assertEqual(f'{"{"}', '{') |
| 656 | self.assertEqual(f'{"}"}', '}') |
| 657 | self.assertEqual(f'{3:{"}"}>10}', '}}}}}}}}}3') |
| 658 | self.assertEqual(f'{2:{"{"}>10}', '{{{{{{{{{2') |
| 659 | |
| 660 | def test_if_conditional(self): |
| 661 | # There's special logic in compile.c to test if the |
| 662 | # conditional for an if (and while) are constants. Exercise |
| 663 | # that code. |
| 664 | |
| 665 | def test_fstring(x, expected): |
| 666 | flag = 0 |
| 667 | if f'{x}': |
| 668 | flag = 1 |
| 669 | else: |
| 670 | flag = 2 |
| 671 | self.assertEqual(flag, expected) |
| 672 | |
| 673 | def test_concat_empty(x, expected): |
| 674 | flag = 0 |
| 675 | if '' f'{x}': |
| 676 | flag = 1 |
| 677 | else: |
| 678 | flag = 2 |
| 679 | self.assertEqual(flag, expected) |
| 680 | |
| 681 | def test_concat_non_empty(x, expected): |
| 682 | flag = 0 |
| 683 | if ' ' f'{x}': |
| 684 | flag = 1 |
| 685 | else: |
| 686 | flag = 2 |
| 687 | self.assertEqual(flag, expected) |
| 688 | |
| 689 | test_fstring('', 2) |
| 690 | test_fstring(' ', 1) |
| 691 | |
| 692 | test_concat_empty('', 2) |
| 693 | test_concat_empty(' ', 1) |
| 694 | |
| 695 | test_concat_non_empty('', 1) |
| 696 | test_concat_non_empty(' ', 1) |
| 697 | |
| 698 | def test_empty_format_specifier(self): |
| 699 | x = 'test' |
| 700 | self.assertEqual(f'{x}', 'test') |
| 701 | self.assertEqual(f'{x:}', 'test') |
| 702 | self.assertEqual(f'{x!s:}', 'test') |
| 703 | self.assertEqual(f'{x!r:}', "'test'") |
| 704 | |
| 705 | def test_str_format_differences(self): |
| 706 | d = {'a': 'string', |
| 707 | 0: 'integer', |
| 708 | } |
| 709 | a = 0 |
| 710 | self.assertEqual(f'{d[0]}', 'integer') |
| 711 | self.assertEqual(f'{d["a"]}', 'string') |
| 712 | self.assertEqual(f'{d[a]}', 'integer') |
| 713 | self.assertEqual('{d[a]}'.format(d=d), 'string') |
| 714 | self.assertEqual('{d[0]}'.format(d=d), 'integer') |
| 715 | |
| 716 | def test_invalid_expressions(self): |
| 717 | self.assertAllRaise(SyntaxError, 'invalid syntax', |
| 718 | [r"f'{a[4)}'", |
| 719 | r"f'{a(4]}'", |
| 720 | ]) |
| 721 | |
Eric V. Smith | 135d5f4 | 2016-02-05 18:23:08 -0500 | [diff] [blame] | 722 | def test_errors(self): |
| 723 | # see issue 26287 |
Serhiy Storchaka | 13c8f32 | 2016-10-31 08:13:00 +0200 | [diff] [blame] | 724 | self.assertAllRaise(TypeError, 'unsupported', |
Eric V. Smith | 135d5f4 | 2016-02-05 18:23:08 -0500 | [diff] [blame] | 725 | [r"f'{(lambda: 0):x}'", |
| 726 | r"f'{(0,):x}'", |
| 727 | ]) |
| 728 | self.assertAllRaise(ValueError, 'Unknown format code', |
| 729 | [r"f'{1000:j}'", |
| 730 | r"f'{1000:j}'", |
| 731 | ]) |
| 732 | |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 733 | def test_loop(self): |
| 734 | for i in range(1000): |
| 735 | self.assertEqual(f'i:{i}', 'i:' + str(i)) |
| 736 | |
| 737 | def test_dict(self): |
| 738 | d = {'"': 'dquote', |
| 739 | "'": 'squote', |
| 740 | 'foo': 'bar', |
| 741 | } |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 742 | self.assertEqual(f'''{d["'"]}''', 'squote') |
| 743 | self.assertEqual(f"""{d['"']}""", 'dquote') |
| 744 | |
| 745 | self.assertEqual(f'{d["foo"]}', 'bar') |
| 746 | self.assertEqual(f"{d['foo']}", 'bar') |
Eric V. Smith | 235a6f0 | 2015-09-19 14:51:32 -0400 | [diff] [blame] | 747 | |
| 748 | if __name__ == '__main__': |
| 749 | unittest.main() |