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