1"""Unit tests for the positional only argument syntax specified in PEP 570.""" 2 3import dis 4import pickle 5import unittest 6 7from test.support import check_syntax_error 8 9 10def global_pos_only_f(a, b, /): 11 return a, b 12 13def global_pos_only_and_normal(a, /, b): 14 return a, b 15 16def global_pos_only_defaults(a=1, /, b=2): 17 return a, b 18 19class PositionalOnlyTestCase(unittest.TestCase): 20 21 def assertRaisesSyntaxError(self, codestr, regex="invalid syntax"): 22 with self.assertRaisesRegex(SyntaxError, regex): 23 compile(codestr + "\n", "<test>", "single") 24 25 def test_invalid_syntax_errors(self): 26 check_syntax_error(self, "def f(a, b = 5, /, c): pass", "parameter without a default follows parameter with a default") 27 check_syntax_error(self, "def f(a = 5, b, /, c): pass", "parameter without a default follows parameter with a default") 28 check_syntax_error(self, "def f(a = 5, b=1, /, c, *, d=2): pass", "parameter without a default follows parameter with a default") 29 check_syntax_error(self, "def f(a = 5, b, /): pass", "parameter without a default follows parameter with a default") 30 check_syntax_error(self, "def f(a, /, b = 5, c): pass", "parameter without a default follows parameter with a default") 31 check_syntax_error(self, "def f(*args, /): pass") 32 check_syntax_error(self, "def f(*args, a, /): pass") 33 check_syntax_error(self, "def f(**kwargs, /): pass") 34 check_syntax_error(self, "def f(/, a = 1): pass") 35 check_syntax_error(self, "def f(/, a): pass") 36 check_syntax_error(self, "def f(/): pass") 37 check_syntax_error(self, "def f(*, a, /): pass") 38 check_syntax_error(self, "def f(*, /, a): pass") 39 check_syntax_error(self, "def f(a, /, a): pass", "duplicate argument 'a' in function definition") 40 check_syntax_error(self, "def f(a, /, *, a): pass", "duplicate argument 'a' in function definition") 41 check_syntax_error(self, "def f(a, b/2, c): pass") 42 check_syntax_error(self, "def f(a, /, c, /): pass") 43 check_syntax_error(self, "def f(a, /, c, /, d): pass") 44 check_syntax_error(self, "def f(a, /, c, /, d, *, e): pass") 45 check_syntax_error(self, "def f(a, *, c, /, d, e): pass") 46 47 def test_invalid_syntax_errors_async(self): 48 check_syntax_error(self, "async def f(a, b = 5, /, c): pass", "parameter without a default follows parameter with a default") 49 check_syntax_error(self, "async def f(a = 5, b, /, c): pass", "parameter without a default follows parameter with a default") 50 check_syntax_error(self, "async def f(a = 5, b=1, /, c, d=2): pass", "parameter without a default follows parameter with a default") 51 check_syntax_error(self, "async def f(a = 5, b, /): pass", "parameter without a default follows parameter with a default") 52 check_syntax_error(self, "async def f(a, /, b = 5, c): pass", "parameter without a default follows parameter with a default") 53 check_syntax_error(self, "async def f(*args, /): pass") 54 check_syntax_error(self, "async def f(*args, a, /): pass") 55 check_syntax_error(self, "async def f(**kwargs, /): pass") 56 check_syntax_error(self, "async def f(/, a = 1): pass") 57 check_syntax_error(self, "async def f(/, a): pass") 58 check_syntax_error(self, "async def f(/): pass") 59 check_syntax_error(self, "async def f(*, a, /): pass") 60 check_syntax_error(self, "async def f(*, /, a): pass") 61 check_syntax_error(self, "async def f(a, /, a): pass", "duplicate argument 'a' in function definition") 62 check_syntax_error(self, "async def f(a, /, *, a): pass", "duplicate argument 'a' in function definition") 63 check_syntax_error(self, "async def f(a, b/2, c): pass") 64 check_syntax_error(self, "async def f(a, /, c, /): pass") 65 check_syntax_error(self, "async def f(a, /, c, /, d): pass") 66 check_syntax_error(self, "async def f(a, /, c, /, d, *, e): pass") 67 check_syntax_error(self, "async def f(a, *, c, /, d, e): pass") 68 69 def test_optional_positional_only_args(self): 70 def f(a, b=10, /, c=100): 71 return a + b + c 72 73 self.assertEqual(f(1, 2, 3), 6) 74 self.assertEqual(f(1, 2, c=3), 6) 75 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"): 76 f(1, b=2, c=3) 77 78 self.assertEqual(f(1, 2), 103) 79 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"): 80 f(1, b=2) 81 self.assertEqual(f(1, c=2), 13) 82 83 def f(a=1, b=10, /, c=100): 84 return a + b + c 85 86 self.assertEqual(f(1, 2, 3), 6) 87 self.assertEqual(f(1, 2, c=3), 6) 88 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"): 89 f(1, b=2, c=3) 90 91 self.assertEqual(f(1, 2), 103) 92 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"): 93 f(1, b=2) 94 self.assertEqual(f(1, c=2), 13) 95 96 def test_syntax_for_many_positional_only(self): 97 # more than 255 positional only arguments, should compile ok 98 fundef = "def f(%s, /):\n pass\n" % ', '.join('i%d' % i for i in range(300)) 99 compile(fundef, "<test>", "single") 100 101 def test_pos_only_definition(self): 102 def f(a, b, c, /, d, e=1, *, f, g=2): 103 pass 104 105 self.assertEqual(5, f.__code__.co_argcount) # 3 posonly + 2 "standard args" 106 self.assertEqual(3, f.__code__.co_posonlyargcount) 107 self.assertEqual((1,), f.__defaults__) 108 109 def f(a, b, c=1, /, d=2, e=3, *, f, g=4): 110 pass 111 112 self.assertEqual(5, f.__code__.co_argcount) # 3 posonly + 2 "standard args" 113 self.assertEqual(3, f.__code__.co_posonlyargcount) 114 self.assertEqual((1, 2, 3), f.__defaults__) 115 116 def test_pos_only_call_via_unpacking(self): 117 def f(a, b, /): 118 return a + b 119 120 self.assertEqual(f(*[1, 2]), 3) 121 122 def test_use_positional_as_keyword(self): 123 def f(a, /): 124 pass 125 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'" 126 with self.assertRaisesRegex(TypeError, expected): 127 f(a=1) 128 129 def f(a, /, b): 130 pass 131 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'" 132 with self.assertRaisesRegex(TypeError, expected): 133 f(a=1, b=2) 134 135 def f(a, b, /): 136 pass 137 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a, b'" 138 with self.assertRaisesRegex(TypeError, expected): 139 f(a=1, b=2) 140 141 def test_positional_only_and_arg_invalid_calls(self): 142 def f(a, b, /, c): 143 pass 144 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'c'"): 145 f(1, 2) 146 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'b' and 'c'"): 147 f(1) 148 with self.assertRaisesRegex(TypeError, r"f\(\) missing 3 required positional arguments: 'a', 'b', and 'c'"): 149 f() 150 with self.assertRaisesRegex(TypeError, r"f\(\) takes 3 positional arguments but 4 were given"): 151 f(1, 2, 3, 4) 152 153 def test_positional_only_and_optional_arg_invalid_calls(self): 154 def f(a, b, /, c=3): 155 pass 156 f(1, 2) # does not raise 157 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'b'"): 158 f(1) 159 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"): 160 f() 161 with self.assertRaisesRegex(TypeError, r"f\(\) takes from 2 to 3 positional arguments but 4 were given"): 162 f(1, 2, 3, 4) 163 164 def test_positional_only_and_kwonlyargs_invalid_calls(self): 165 def f(a, b, /, c, *, d, e): 166 pass 167 f(1, 2, 3, d=1, e=2) # does not raise 168 with self.assertRaisesRegex(TypeError, r"missing 1 required keyword-only argument: 'd'"): 169 f(1, 2, 3, e=2) 170 with self.assertRaisesRegex(TypeError, r"missing 2 required keyword-only arguments: 'd' and 'e'"): 171 f(1, 2, 3) 172 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'c'"): 173 f(1, 2) 174 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'b' and 'c'"): 175 f(1) 176 with self.assertRaisesRegex(TypeError, r" missing 3 required positional arguments: 'a', 'b', and 'c'"): 177 f() 178 with self.assertRaisesRegex(TypeError, r"f\(\) takes 3 positional arguments but 6 positional arguments " 179 r"\(and 2 keyword-only arguments\) were given"): 180 f(1, 2, 3, 4, 5, 6, d=7, e=8) 181 with self.assertRaisesRegex(TypeError, r"f\(\) got an unexpected keyword argument 'f'"): 182 f(1, 2, 3, d=1, e=4, f=56) 183 184 def test_positional_only_invalid_calls(self): 185 def f(a, b, /): 186 pass 187 f(1, 2) # does not raise 188 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'b'"): 189 f(1) 190 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"): 191 f() 192 with self.assertRaisesRegex(TypeError, r"f\(\) takes 2 positional arguments but 3 were given"): 193 f(1, 2, 3) 194 195 def test_positional_only_with_optional_invalid_calls(self): 196 def f(a, b=2, /): 197 pass 198 f(1) # does not raise 199 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'a'"): 200 f() 201 202 with self.assertRaisesRegex(TypeError, r"f\(\) takes from 1 to 2 positional arguments but 3 were given"): 203 f(1, 2, 3) 204 205 def test_no_standard_args_usage(self): 206 def f(a, b, /, *, c): 207 pass 208 209 f(1, 2, c=3) 210 with self.assertRaises(TypeError): 211 f(1, b=2, c=3) 212 213 def test_change_default_pos_only(self): 214 def f(a, b=2, /, c=3): 215 return a + b + c 216 217 self.assertEqual((2,3), f.__defaults__) 218 f.__defaults__ = (1, 2, 3) 219 self.assertEqual(f(1, 2, 3), 6) 220 221 def test_lambdas(self): 222 x = lambda a, /, b: a + b 223 self.assertEqual(x(1,2), 3) 224 self.assertEqual(x(1,b=2), 3) 225 226 x = lambda a, /, b=2: a + b 227 self.assertEqual(x(1), 3) 228 229 x = lambda a, b, /: a + b 230 self.assertEqual(x(1, 2), 3) 231 232 x = lambda a, b, /, : a + b 233 self.assertEqual(x(1, 2), 3) 234 235 def test_invalid_syntax_lambda(self): 236 check_syntax_error(self, "lambda a, b = 5, /, c: None", "parameter without a default follows parameter with a default") 237 check_syntax_error(self, "lambda a = 5, b, /, c: None", "parameter without a default follows parameter with a default") 238 check_syntax_error(self, "lambda a = 5, b=1, /, c, *, d=2: None", "parameter without a default follows parameter with a default") 239 check_syntax_error(self, "lambda a = 5, b, /: None", "parameter without a default follows parameter with a default") 240 check_syntax_error(self, "lambda a, /, b = 5, c: None", "parameter without a default follows parameter with a default") 241 check_syntax_error(self, "lambda *args, /: None") 242 check_syntax_error(self, "lambda *args, a, /: None") 243 check_syntax_error(self, "lambda **kwargs, /: None") 244 check_syntax_error(self, "lambda /, a = 1: None") 245 check_syntax_error(self, "lambda /, a: None") 246 check_syntax_error(self, "lambda /: None") 247 check_syntax_error(self, "lambda *, a, /: None") 248 check_syntax_error(self, "lambda *, /, a: None") 249 check_syntax_error(self, "lambda a, /, a: None", "duplicate argument 'a' in function definition") 250 check_syntax_error(self, "lambda a, /, *, a: None", "duplicate argument 'a' in function definition") 251 check_syntax_error(self, "lambda a, /, b, /: None") 252 check_syntax_error(self, "lambda a, /, b, /, c: None") 253 check_syntax_error(self, "lambda a, /, b, /, c, *, d: None") 254 check_syntax_error(self, "lambda a, *, b, /, c: None") 255 256 def test_posonly_methods(self): 257 class Example: 258 def f(self, a, b, /): 259 return a, b 260 261 self.assertEqual(Example().f(1, 2), (1, 2)) 262 self.assertEqual(Example.f(Example(), 1, 2), (1, 2)) 263 self.assertRaises(TypeError, Example.f, 1, 2) 264 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'" 265 with self.assertRaisesRegex(TypeError, expected): 266 Example().f(1, b=2) 267 268 def test_module_function(self): 269 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"): 270 global_pos_only_f() 271 272 273 def test_closures(self): 274 def f(x,y): 275 def g(x2,/,y2): 276 return x + y + x2 + y2 277 return g 278 279 self.assertEqual(f(1,2)(3,4), 10) 280 with self.assertRaisesRegex(TypeError, r"g\(\) missing 1 required positional argument: 'y2'"): 281 f(1,2)(3) 282 with self.assertRaisesRegex(TypeError, r"g\(\) takes 2 positional arguments but 3 were given"): 283 f(1,2)(3,4,5) 284 285 def f(x,/,y): 286 def g(x2,y2): 287 return x + y + x2 + y2 288 return g 289 290 self.assertEqual(f(1,2)(3,4), 10) 291 292 def f(x,/,y): 293 def g(x2,/,y2): 294 return x + y + x2 + y2 295 return g 296 297 self.assertEqual(f(1,2)(3,4), 10) 298 with self.assertRaisesRegex(TypeError, r"g\(\) missing 1 required positional argument: 'y2'"): 299 f(1,2)(3) 300 with self.assertRaisesRegex(TypeError, r"g\(\) takes 2 positional arguments but 3 were given"): 301 f(1,2)(3,4,5) 302 303 def test_annotations_in_closures(self): 304 305 def inner_has_pos_only(): 306 def f(x: int, /): ... 307 return f 308 309 assert inner_has_pos_only().__annotations__ == {'x': int} 310 311 class Something: 312 def method(self): 313 def f(x: int, /): ... 314 return f 315 316 assert Something().method().__annotations__ == {'x': int} 317 318 def multiple_levels(): 319 def inner_has_pos_only(): 320 def f(x: int, /): ... 321 return f 322 return inner_has_pos_only() 323 324 assert multiple_levels().__annotations__ == {'x': int} 325 326 def test_same_keyword_as_positional_with_kwargs(self): 327 def f(something,/,**kwargs): 328 return (something, kwargs) 329 330 self.assertEqual(f(42, something=42), (42, {'something': 42})) 331 332 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'something'"): 333 f(something=42) 334 335 self.assertEqual(f(42), (42, {})) 336 337 def test_mangling(self): 338 class X: 339 def f(self, __a=42, /): 340 return __a 341 342 def f2(self, __a=42, /, __b=43): 343 return (__a, __b) 344 345 def f3(self, __a=42, /, __b=43, *, __c=44): 346 return (__a, __b, __c) 347 348 self.assertEqual(X().f(), 42) 349 self.assertEqual(X().f2(), (42, 43)) 350 self.assertEqual(X().f3(), (42, 43, 44)) 351 352 def test_too_many_arguments(self): 353 # more than 255 positional-only arguments, should compile ok 354 fundef = "def f(%s, /):\n pass\n" % ', '.join('i%d' % i for i in range(300)) 355 compile(fundef, "<test>", "single") 356 357 def test_serialization(self): 358 pickled_posonly = pickle.dumps(global_pos_only_f) 359 pickled_optional = pickle.dumps(global_pos_only_and_normal) 360 pickled_defaults = pickle.dumps(global_pos_only_defaults) 361 362 unpickled_posonly = pickle.loads(pickled_posonly) 363 unpickled_optional = pickle.loads(pickled_optional) 364 unpickled_defaults = pickle.loads(pickled_defaults) 365 366 self.assertEqual(unpickled_posonly(1,2), (1,2)) 367 expected = r"global_pos_only_f\(\) got some positional-only arguments "\ 368 r"passed as keyword arguments: 'a, b'" 369 with self.assertRaisesRegex(TypeError, expected): 370 unpickled_posonly(a=1,b=2) 371 372 self.assertEqual(unpickled_optional(1,2), (1,2)) 373 expected = r"global_pos_only_and_normal\(\) got some positional-only arguments "\ 374 r"passed as keyword arguments: 'a'" 375 with self.assertRaisesRegex(TypeError, expected): 376 unpickled_optional(a=1,b=2) 377 378 self.assertEqual(unpickled_defaults(), (1,2)) 379 expected = r"global_pos_only_defaults\(\) got some positional-only arguments "\ 380 r"passed as keyword arguments: 'a'" 381 with self.assertRaisesRegex(TypeError, expected): 382 unpickled_defaults(a=1,b=2) 383 384 def test_async(self): 385 386 async def f(a=1, /, b=2): 387 return a, b 388 389 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"): 390 f(a=1, b=2) 391 392 def _check_call(*args, **kwargs): 393 try: 394 coro = f(*args, **kwargs) 395 coro.send(None) 396 except StopIteration as e: 397 result = e.value 398 self.assertEqual(result, (1, 2)) 399 400 _check_call(1, 2) 401 _check_call(1, b=2) 402 _check_call(1) 403 _check_call() 404 405 def test_generator(self): 406 407 def f(a=1, /, b=2): 408 yield a, b 409 410 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"): 411 f(a=1, b=2) 412 413 gen = f(1, 2) 414 self.assertEqual(next(gen), (1, 2)) 415 gen = f(1, b=2) 416 self.assertEqual(next(gen), (1, 2)) 417 gen = f(1) 418 self.assertEqual(next(gen), (1, 2)) 419 gen = f() 420 self.assertEqual(next(gen), (1, 2)) 421 422 def test_super(self): 423 424 sentinel = object() 425 426 class A: 427 def method(self): 428 return sentinel 429 430 class C(A): 431 def method(self, /): 432 return super().method() 433 434 self.assertEqual(C().method(), sentinel) 435 436 def test_annotations_constant_fold(self): 437 def g(): 438 def f(x: not (int is int), /): ... 439 440 # without constant folding we end up with 441 # COMPARE_OP(is), IS_OP (0) 442 # with constant folding we should expect a IS_OP (1) 443 codes = [(i.opname, i.argval) for i in dis.get_instructions(g)] 444 self.assertNotIn(('UNARY_NOT', None), codes) 445 self.assertIn(('IS_OP', 1), codes) 446 447 448if __name__ == "__main__": 449 unittest.main() 450