cpython/Lib/test/test_positional_only_arg.py

435 lines
17 KiB
Python
Raw Normal View History

"""Unit tests for the positional only argument syntax specified in PEP 570."""
import dis
import pickle
import unittest
from test.support import check_syntax_error
def global_pos_only_f(a, b, /):
return a, b
def global_pos_only_and_normal(a, /, b):
return a, b
def global_pos_only_defaults(a=1, /, b=2):
return a, b
class PositionalOnlyTestCase(unittest.TestCase):
def assertRaisesSyntaxError(self, codestr, regex="invalid syntax"):
with self.assertRaisesRegex(SyntaxError, regex):
compile(codestr + "\n", "<test>", "single")
def test_invalid_syntax_errors(self):
check_syntax_error(self, "def f(a, b = 5, /, c): pass", "non-default argument follows default argument")
check_syntax_error(self, "def f(a = 5, b, /, c): pass", "non-default argument follows default argument")
check_syntax_error(self, "def f(a = 5, b=1, /, c, *, d=2): pass", "non-default argument follows default argument")
check_syntax_error(self, "def f(a = 5, b, /): pass", "non-default argument follows default argument")
check_syntax_error(self, "def f(*args, /): pass")
check_syntax_error(self, "def f(*args, a, /): pass")
check_syntax_error(self, "def f(**kwargs, /): pass")
check_syntax_error(self, "def f(/, a = 1): pass")
check_syntax_error(self, "def f(/, a): pass")
check_syntax_error(self, "def f(/): pass")
check_syntax_error(self, "def f(*, a, /): pass")
check_syntax_error(self, "def f(*, /, a): pass")
check_syntax_error(self, "def f(a, /, a): pass", "duplicate argument 'a' in function definition")
check_syntax_error(self, "def f(a, /, *, a): pass", "duplicate argument 'a' in function definition")
check_syntax_error(self, "def f(a, b/2, c): pass")
check_syntax_error(self, "def f(a, /, c, /): pass")
check_syntax_error(self, "def f(a, /, c, /, d): pass")
check_syntax_error(self, "def f(a, /, c, /, d, *, e): pass")
check_syntax_error(self, "def f(a, *, c, /, d, e): pass")
def test_invalid_syntax_errors_async(self):
check_syntax_error(self, "async def f(a, b = 5, /, c): pass", "non-default argument follows default argument")
check_syntax_error(self, "async def f(a = 5, b, /, c): pass", "non-default argument follows default argument")
check_syntax_error(self, "async def f(a = 5, b=1, /, c, d=2): pass", "non-default argument follows default argument")
check_syntax_error(self, "async def f(a = 5, b, /): pass", "non-default argument follows default argument")
check_syntax_error(self, "async def f(*args, /): pass")
check_syntax_error(self, "async def f(*args, a, /): pass")
check_syntax_error(self, "async def f(**kwargs, /): pass")
check_syntax_error(self, "async def f(/, a = 1): pass")
check_syntax_error(self, "async def f(/, a): pass")
check_syntax_error(self, "async def f(/): pass")
check_syntax_error(self, "async def f(*, a, /): pass")
check_syntax_error(self, "async def f(*, /, a): pass")
check_syntax_error(self, "async def f(a, /, a): pass", "duplicate argument 'a' in function definition")
check_syntax_error(self, "async def f(a, /, *, a): pass", "duplicate argument 'a' in function definition")
check_syntax_error(self, "async def f(a, b/2, c): pass")
check_syntax_error(self, "async def f(a, /, c, /): pass")
check_syntax_error(self, "async def f(a, /, c, /, d): pass")
check_syntax_error(self, "async def f(a, /, c, /, d, *, e): pass")
check_syntax_error(self, "async def f(a, *, c, /, d, e): pass")
def test_optional_positional_only_args(self):
def f(a, b=10, /, c=100):
return a + b + c
self.assertEqual(f(1, 2, 3), 6)
self.assertEqual(f(1, 2, c=3), 6)
with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
f(1, b=2, c=3)
self.assertEqual(f(1, 2), 103)
with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
f(1, b=2)
self.assertEqual(f(1, c=2), 13)
def f(a=1, b=10, /, c=100):
return a + b + c
self.assertEqual(f(1, 2, 3), 6)
self.assertEqual(f(1, 2, c=3), 6)
with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
f(1, b=2, c=3)
self.assertEqual(f(1, 2), 103)
with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
f(1, b=2)
self.assertEqual(f(1, c=2), 13)
def test_syntax_for_many_positional_only(self):
# more than 255 positional only arguments, should compile ok
fundef = "def f(%s, /):\n pass\n" % ', '.join('i%d' % i for i in range(300))
compile(fundef, "<test>", "single")
def test_pos_only_definition(self):
def f(a, b, c, /, d, e=1, *, f, g=2):
pass
self.assertEqual(5, f.__code__.co_argcount) # 3 posonly + 2 "standard args"
self.assertEqual(3, f.__code__.co_posonlyargcount)
self.assertEqual((1,), f.__defaults__)
def f(a, b, c=1, /, d=2, e=3, *, f, g=4):
pass
self.assertEqual(5, f.__code__.co_argcount) # 3 posonly + 2 "standard args"
self.assertEqual(3, f.__code__.co_posonlyargcount)
self.assertEqual((1, 2, 3), f.__defaults__)
def test_pos_only_call_via_unpacking(self):
def f(a, b, /):
return a + b
self.assertEqual(f(*[1, 2]), 3)
def test_use_positional_as_keyword(self):
def f(a, /):
pass
expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"
with self.assertRaisesRegex(TypeError, expected):
f(a=1)
def f(a, /, b):
pass
expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"
with self.assertRaisesRegex(TypeError, expected):
f(a=1, b=2)
def f(a, b, /):
pass
expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a, b'"
with self.assertRaisesRegex(TypeError, expected):
f(a=1, b=2)
def test_positional_only_and_arg_invalid_calls(self):
def f(a, b, /, c):
pass
with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'c'"):
f(1, 2)
with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'b' and 'c'"):
f(1)
with self.assertRaisesRegex(TypeError, r"f\(\) missing 3 required positional arguments: 'a', 'b', and 'c'"):
f()
with self.assertRaisesRegex(TypeError, r"f\(\) takes 3 positional arguments but 4 were given"):
f(1, 2, 3, 4)
def test_positional_only_and_optional_arg_invalid_calls(self):
def f(a, b, /, c=3):
pass
f(1, 2) # does not raise
with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'b'"):
f(1)
with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"):
f()
with self.assertRaisesRegex(TypeError, r"f\(\) takes from 2 to 3 positional arguments but 4 were given"):
f(1, 2, 3, 4)
def test_positional_only_and_kwonlyargs_invalid_calls(self):
def f(a, b, /, c, *, d, e):
pass
f(1, 2, 3, d=1, e=2) # does not raise
with self.assertRaisesRegex(TypeError, r"missing 1 required keyword-only argument: 'd'"):
f(1, 2, 3, e=2)
with self.assertRaisesRegex(TypeError, r"missing 2 required keyword-only arguments: 'd' and 'e'"):
f(1, 2, 3)
with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'c'"):
f(1, 2)
with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'b' and 'c'"):
f(1)
with self.assertRaisesRegex(TypeError, r" missing 3 required positional arguments: 'a', 'b', and 'c'"):
f()
with self.assertRaisesRegex(TypeError, r"f\(\) takes 3 positional arguments but 6 positional arguments "
r"\(and 2 keyword-only arguments\) were given"):
f(1, 2, 3, 4, 5, 6, d=7, e=8)
with self.assertRaisesRegex(TypeError, r"f\(\) got an unexpected keyword argument 'f'"):
f(1, 2, 3, d=1, e=4, f=56)
def test_positional_only_invalid_calls(self):
def f(a, b, /):
pass
f(1, 2) # does not raise
with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'b'"):
f(1)
with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"):
f()
with self.assertRaisesRegex(TypeError, r"f\(\) takes 2 positional arguments but 3 were given"):
f(1, 2, 3)
def test_positional_only_with_optional_invalid_calls(self):
def f(a, b=2, /):
pass
f(1) # does not raise
with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'a'"):
f()
with self.assertRaisesRegex(TypeError, r"f\(\) takes from 1 to 2 positional arguments but 3 were given"):
f(1, 2, 3)
def test_no_standard_args_usage(self):
def f(a, b, /, *, c):
pass
f(1, 2, c=3)
with self.assertRaises(TypeError):
f(1, b=2, c=3)
def test_change_default_pos_only(self):
def f(a, b=2, /, c=3):
return a + b + c
self.assertEqual((2,3), f.__defaults__)
f.__defaults__ = (1, 2, 3)
self.assertEqual(f(1, 2, 3), 6)
def test_lambdas(self):
x = lambda a, /, b: a + b
self.assertEqual(x(1,2), 3)
self.assertEqual(x(1,b=2), 3)
x = lambda a, /, b=2: a + b
self.assertEqual(x(1), 3)
x = lambda a, b, /: a + b
self.assertEqual(x(1, 2), 3)
x = lambda a, b, /, : a + b
self.assertEqual(x(1, 2), 3)
def test_invalid_syntax_lambda(self):
check_syntax_error(self, "lambda a, b = 5, /, c: None", "non-default argument follows default argument")
check_syntax_error(self, "lambda a = 5, b, /, c: None", "non-default argument follows default argument")
check_syntax_error(self, "lambda a = 5, b, /: None", "non-default argument follows default argument")
check_syntax_error(self, "lambda *args, /: None")
check_syntax_error(self, "lambda *args, a, /: None")
check_syntax_error(self, "lambda **kwargs, /: None")
check_syntax_error(self, "lambda /, a = 1: None")
check_syntax_error(self, "lambda /, a: None")
check_syntax_error(self, "lambda /: None")
check_syntax_error(self, "lambda *, a, /: None")
check_syntax_error(self, "lambda *, /, a: None")
check_syntax_error(self, "lambda a, /, a: None", "duplicate argument 'a' in function definition")
check_syntax_error(self, "lambda a, /, *, a: None", "duplicate argument 'a' in function definition")
check_syntax_error(self, "lambda a, /, b, /: None")
check_syntax_error(self, "lambda a, /, b, /, c: None")
check_syntax_error(self, "lambda a, /, b, /, c, *, d: None")
check_syntax_error(self, "lambda a, *, b, /, c: None")
def test_posonly_methods(self):
class Example:
def f(self, a, b, /):
return a, b
self.assertEqual(Example().f(1, 2), (1, 2))
self.assertEqual(Example.f(Example(), 1, 2), (1, 2))
self.assertRaises(TypeError, Example.f, 1, 2)
expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"
with self.assertRaisesRegex(TypeError, expected):
Example().f(1, b=2)
def test_module_function(self):
with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"):
global_pos_only_f()
def test_closures(self):
def f(x,y):
def g(x2,/,y2):
return x + y + x2 + y2
return g
self.assertEqual(f(1,2)(3,4), 10)
with self.assertRaisesRegex(TypeError, r"g\(\) missing 1 required positional argument: 'y2'"):
f(1,2)(3)
with self.assertRaisesRegex(TypeError, r"g\(\) takes 2 positional arguments but 3 were given"):
f(1,2)(3,4,5)
def f(x,/,y):
def g(x2,y2):
return x + y + x2 + y2
return g
self.assertEqual(f(1,2)(3,4), 10)
def f(x,/,y):
def g(x2,/,y2):
return x + y + x2 + y2
return g
self.assertEqual(f(1,2)(3,4), 10)
with self.assertRaisesRegex(TypeError, r"g\(\) missing 1 required positional argument: 'y2'"):
f(1,2)(3)
with self.assertRaisesRegex(TypeError, r"g\(\) takes 2 positional arguments but 3 were given"):
f(1,2)(3,4,5)
def test_annotations_in_closures(self):
def inner_has_pos_only():
def f(x: int, /): ...
return f
assert inner_has_pos_only().__annotations__ == {'x': 'int'}
class Something:
def method(self):
def f(x: int, /): ...
return f
assert Something().method().__annotations__ == {'x': 'int'}
def multiple_levels():
def inner_has_pos_only():
def f(x: int, /): ...
return f
return inner_has_pos_only()
assert multiple_levels().__annotations__ == {'x': 'int'}
def test_same_keyword_as_positional_with_kwargs(self):
def f(something,/,**kwargs):
return (something, kwargs)
self.assertEqual(f(42, something=42), (42, {'something': 42}))
with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'something'"):
f(something=42)
self.assertEqual(f(42), (42, {}))
def test_mangling(self):
class X:
def f(self, __a=42, /):
return __a
def f2(self, __a=42, /, __b=43):
return (__a, __b)
def f3(self, __a=42, /, __b=43, *, __c=44):
return (__a, __b, __c)
self.assertEqual(X().f(), 42)
self.assertEqual(X().f2(), (42, 43))
self.assertEqual(X().f3(), (42, 43, 44))
def test_too_many_arguments(self):
# more than 255 positional-only arguments, should compile ok
fundef = "def f(%s, /):\n pass\n" % ', '.join('i%d' % i for i in range(300))
compile(fundef, "<test>", "single")
def test_serialization(self):
pickled_posonly = pickle.dumps(global_pos_only_f)
pickled_optional = pickle.dumps(global_pos_only_and_normal)
pickled_defaults = pickle.dumps(global_pos_only_defaults)
unpickled_posonly = pickle.loads(pickled_posonly)
unpickled_optional = pickle.loads(pickled_optional)
unpickled_defaults = pickle.loads(pickled_defaults)
self.assertEqual(unpickled_posonly(1,2), (1,2))
expected = r"global_pos_only_f\(\) got some positional-only arguments "\
r"passed as keyword arguments: 'a, b'"
with self.assertRaisesRegex(TypeError, expected):
unpickled_posonly(a=1,b=2)
self.assertEqual(unpickled_optional(1,2), (1,2))
expected = r"global_pos_only_and_normal\(\) got some positional-only arguments "\
r"passed as keyword arguments: 'a'"
with self.assertRaisesRegex(TypeError, expected):
unpickled_optional(a=1,b=2)
self.assertEqual(unpickled_defaults(), (1,2))
expected = r"global_pos_only_defaults\(\) got some positional-only arguments "\
r"passed as keyword arguments: 'a'"
with self.assertRaisesRegex(TypeError, expected):
unpickled_defaults(a=1,b=2)
def test_async(self):
async def f(a=1, /, b=2):
return a, b
with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"):
f(a=1, b=2)
def _check_call(*args, **kwargs):
try:
coro = f(*args, **kwargs)
coro.send(None)
except StopIteration as e:
result = e.value
self.assertEqual(result, (1, 2))
_check_call(1, 2)
_check_call(1, b=2)
_check_call(1)
_check_call()
def test_generator(self):
def f(a=1, /, b=2):
yield a, b
with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"):
f(a=1, b=2)
gen = f(1, 2)
self.assertEqual(next(gen), (1, 2))
gen = f(1, b=2)
self.assertEqual(next(gen), (1, 2))
gen = f(1)
self.assertEqual(next(gen), (1, 2))
gen = f()
self.assertEqual(next(gen), (1, 2))
def test_super(self):
sentinel = object()
class A:
def method(self):
return sentinel
class C(A):
def method(self, /):
return super().method()
self.assertEqual(C().method(), sentinel)
if __name__ == "__main__":
unittest.main()