"""This module tests SyntaxErrors.

Here's an example of the sort of thing that is tested.

>>> def f(x):

... global x

Traceback (most recent call last):

SyntaxError: name 'x' is parameter and global

The tests are all raise SyntaxErrors. They were created by checking

each C call that raises SyntaxError. There are several modules that

raise these exceptions-- ast.c, compile.c, future.c, pythonrun.c, and

symtable.c.

The parser itself outlaws a lot of invalid syntax. None of these

errors are tested here at the moment. We should add some tests; since

there are infinitely many programs with invalid syntax, we would need

to be judicious in selecting some.

The compiler generates a synthetic module name for code executed by

doctest. Since all the code comes from the same module, a suffix like

[1] is appended to the module name, As a consequence, changing the

order of tests in this module means renumbering all the errors after

it. (Maybe we should enable the ellipsis option for these tests.)

In ast.c, syntax errors are raised by calling ast_error().

Errors from set_context():

>>> obj.None = 1

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> None = 1

Traceback (most recent call last):

SyntaxError: cannot assign to None

>>> obj.True = 1

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> True = 1

Traceback (most recent call last):

SyntaxError: cannot assign to True

>>> (True := 1)

Traceback (most recent call last):

SyntaxError: cannot use assignment expressions with True

>>> obj.__debug__ = 1

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> __debug__ = 1

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> (__debug__ := 1)

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> def __debug__(): pass

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> async def __debug__(): pass

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> class __debug__: pass

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> del __debug__

Traceback (most recent call last):

SyntaxError: cannot delete __debug__

>>> f() = 1

Traceback (most recent call last):

SyntaxError: cannot assign to function call here. Maybe you meant '==' instead of '='?

>>> yield = 1

Traceback (most recent call last):

SyntaxError: assignment to yield expression not possible

>>> del f()

Traceback (most recent call last):

SyntaxError: cannot delete function call

>>> a + 1 = 2

Traceback (most recent call last):

SyntaxError: cannot assign to expression here. Maybe you meant '==' instead of '='?

>>> (x for x in x) = 1

Traceback (most recent call last):

SyntaxError: cannot assign to generator expression

>>> 1 = 1

Traceback (most recent call last):

SyntaxError: cannot assign to literal here. Maybe you meant '==' instead of '='?

>>> "abc" = 1

Traceback (most recent call last):

SyntaxError: cannot assign to literal here. Maybe you meant '==' instead of '='?

>>> b"" = 1

Traceback (most recent call last):

SyntaxError: cannot assign to literal here. Maybe you meant '==' instead of '='?

>>> ... = 1

Traceback (most recent call last):

SyntaxError: cannot assign to ellipsis here. Maybe you meant '==' instead of '='?

>>> `1` = 1

Traceback (most recent call last):

SyntaxError: invalid syntax

If the left-hand side of an assignment is a list or tuple, an illegal

expression inside that contain should still cause a syntax error.

This test just checks a couple of cases rather than enumerating all of

them.

>>> (a, "b", c) = (1, 2, 3)

Traceback (most recent call last):

SyntaxError: cannot assign to literal

>>> (a, True, c) = (1, 2, 3)

Traceback (most recent call last):

SyntaxError: cannot assign to True

>>> (a, __debug__, c) = (1, 2, 3)

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> (a, *True, c) = (1, 2, 3)

Traceback (most recent call last):

SyntaxError: cannot assign to True

>>> (a, *__debug__, c) = (1, 2, 3)

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> [a, b, c + 1] = [1, 2, 3]

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> [a, b[1], c + 1] = [1, 2, 3]

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> [a, b.c.d, c + 1] = [1, 2, 3]

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> a if 1 else b = 1

Traceback (most recent call last):

SyntaxError: cannot assign to conditional expression

>>> a = 42 if True

Traceback (most recent call last):

SyntaxError: expected 'else' after 'if' expression

>>> a = (42 if True)

Traceback (most recent call last):

SyntaxError: expected 'else' after 'if' expression

>>> a = [1, 42 if True, 4]

Traceback (most recent call last):

SyntaxError: expected 'else' after 'if' expression

>>> x = 1 if 1 else pass

Traceback (most recent call last):

SyntaxError: expected expression after 'else', but statement is given

>>> x = pass if 1 else 1

Traceback (most recent call last):

SyntaxError: expected expression before 'if', but statement is given

>>> x = pass if 1 else pass

Traceback (most recent call last):

SyntaxError: expected expression before 'if', but statement is given

>>> if True:

... print("Hello"

...

... if 2:

... print(123))

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> True = True = 3

Traceback (most recent call last):

SyntaxError: cannot assign to True

>>> x = y = True = z = 3

Traceback (most recent call last):

SyntaxError: cannot assign to True

>>> x = y = yield = 1

Traceback (most recent call last):

SyntaxError: assignment to yield expression not possible

>>> a, b += 1, 2

Traceback (most recent call last):

SyntaxError: 'tuple' is an illegal expression for augmented assignment

>>> (a, b) += 1, 2

Traceback (most recent call last):

SyntaxError: 'tuple' is an illegal expression for augmented assignment

>>> [a, b] += 1, 2

Traceback (most recent call last):

SyntaxError: 'list' is an illegal expression for augmented assignment

Invalid targets in `for` loops and `with` statements should also

produce a specialized error message

>>> for a() in b: pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> for (a, b()) in b: pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> for [a, b()] in b: pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> for (*a, b, c+1) in b: pass

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> for (x, *(y, z.d())) in b: pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> for a, b() in c: pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> for a, b, (c + 1, d()): pass

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> for i < (): pass

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> for a, b

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> with a as b(): pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> with a as (b, c()): pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> with a as [b, c()]: pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> with a as (*b, c, d+1): pass

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> with a as (x, *(y, z.d())): pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> with a as b, c as d(): pass

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> with a as b

Traceback (most recent call last):

SyntaxError: expected ':'

>>> p = p =

Traceback (most recent call last):

SyntaxError: invalid syntax

Comprehensions without 'in' keyword:

>>> [x for x if range(1)]

Traceback (most recent call last):

SyntaxError: 'in' expected after for-loop variables

>>> tuple(x for x if range(1))

Traceback (most recent call last):

SyntaxError: 'in' expected after for-loop variables

>>> [x for x() in a]

Traceback (most recent call last):

SyntaxError: cannot assign to function call

>>> [x for a, b, (c + 1, d()) in y]

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> [x for a, b, (c + 1, d()) if y]

Traceback (most recent call last):

SyntaxError: 'in' expected after for-loop variables

>>> [x for x+1 in y]

Traceback (most recent call last):

SyntaxError: cannot assign to expression

>>> [x for x+1, x() in y]

Traceback (most recent call last):

SyntaxError: cannot assign to expression

Comprehensions creating tuples without parentheses

should produce a specialized error message:

>>> [x,y for x,y in range(100)]

Traceback (most recent call last):

SyntaxError: did you forget parentheses around the comprehension target?

>>> {x,y for x,y in range(100)}

Traceback (most recent call last):

SyntaxError: did you forget parentheses around the comprehension target?

# Incorrectly closed strings

>>> "The interesting object "The important object" is very important"

Traceback (most recent call last):

SyntaxError: invalid syntax. Is this intended to be part of the string?

# Missing commas in literals collections should not

# produce special error messages regarding missing

# parentheses, but about missing commas instead

>>> [1, 2 3]

Traceback (most recent call last):

SyntaxError: invalid syntax. Perhaps you forgot a comma?

>>> {1, 2 3}

Traceback (most recent call last):

SyntaxError: invalid syntax. Perhaps you forgot a comma?

>>> {1:2, 2:5 3:12}

Traceback (most recent call last):

SyntaxError: invalid syntax. Perhaps you forgot a comma?

>>> (1, 2 3)

Traceback (most recent call last):

SyntaxError: invalid syntax. Perhaps you forgot a comma?

# Make sure soft keywords constructs don't raise specialized

# errors regarding missing commas or other spezialiced errors

>>> match x:

... y = 3

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> match x:

... case y:

... 3 $ 3

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> match x:

... case $:

... ...

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> match ...:

... case {**rest, "key": value}:

... ...

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> match ...:

... case {**_}:

... ...

Traceback (most recent call last):

SyntaxError: invalid syntax

From compiler_complex_args():

>>> def f(None=1):

... pass

Traceback (most recent call last):

SyntaxError: invalid syntax

From ast_for_arguments():

>>> def f(x, y=1, z):

... pass

Traceback (most recent call last):

SyntaxError: parameter without a default follows parameter with a default

>>> def f(x, /, y=1, z):

... pass

Traceback (most recent call last):

SyntaxError: parameter without a default follows parameter with a default

>>> def f(x, None):

... pass

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> def f(*None):

... pass

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> def f(**None):

... pass

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> def foo(/,a,b=,c):

... pass

Traceback (most recent call last):

SyntaxError: at least one parameter must precede /

>>> def foo(a,/,/,b,c):

... pass

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> def foo(a,/,a1,/,b,c):

... pass

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> def foo(a=1,/,/,*b,/,c):

... pass

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> def foo(a,/,a1=1,/,b,c):

... pass

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> def foo(a,*b,c,/,d,e):

... pass

Traceback (most recent call last):

SyntaxError: / must be ahead of *

>>> def foo(a=1,*b,c=3,/,d,e):

... pass

Traceback (most recent call last):

SyntaxError: / must be ahead of *

>>> def foo(a,*b=3,c):

... pass

Traceback (most recent call last):

SyntaxError: var-positional parameter cannot have default value

>>> def foo(a,*b: int=,c):

... pass

Traceback (most recent call last):

SyntaxError: var-positional parameter cannot have default value

>>> def foo(a,**b=3):

... pass

Traceback (most recent call last):

SyntaxError: var-keyword parameter cannot have default value

>>> def foo(a,**b: int=3):

... pass

Traceback (most recent call last):

SyntaxError: var-keyword parameter cannot have default value

>>> def foo(a,*a, b, **c, d):

... pass

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> def foo(a,*a, b, **c, d=4):

... pass

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> def foo(a,*a, b, **c, *d):

... pass

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> def foo(a,*a, b, **c, **d):

... pass

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> def foo(a=1,/,**b,/,c):

... pass

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> def foo(*b,*d):

... pass

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> def foo(a,*b,c,*d,*e,c):

... pass

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> def foo(a,b,/,c,*b,c,*d,*e,c):

... pass

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> def foo(a,b,/,c,*b,c,*d,**e):

... pass

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> def foo(a=1,/*,b,c):

... pass

Traceback (most recent call last):

SyntaxError: expected comma between / and *

>>> def foo(a=1,d=,c):

... pass

Traceback (most recent call last):

SyntaxError: expected default value expression

>>> def foo(a,d=,c):

... pass

Traceback (most recent call last):

SyntaxError: expected default value expression

>>> def foo(a,d: int=,c):

... pass

Traceback (most recent call last):

SyntaxError: expected default value expression

>>> lambda /,a,b,c: None

Traceback (most recent call last):

SyntaxError: at least one parameter must precede /

>>> lambda a,/,/,b,c: None

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> lambda a,/,a1,/,b,c: None

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> lambda a=1,/,/,*b,/,c: None

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> lambda a,/,a1=1,/,b,c: None

Traceback (most recent call last):

SyntaxError: / may appear only once

>>> lambda a,*b,c,/,d,e: None

Traceback (most recent call last):

SyntaxError: / must be ahead of *

>>> lambda a=1,*b,c=3,/,d,e: None

Traceback (most recent call last):

SyntaxError: / must be ahead of *

>>> lambda a=1,/*,b,c: None

Traceback (most recent call last):

SyntaxError: expected comma between / and *

>>> lambda a,*b=3,c: None

Traceback (most recent call last):

SyntaxError: var-positional parameter cannot have default value

>>> lambda a,**b=3: None

Traceback (most recent call last):

SyntaxError: var-keyword parameter cannot have default value

>>> lambda a, *a, b, **c, d: None

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> lambda a,*a, b, **c, d=4: None

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> lambda a,*a, b, **c, *d: None

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> lambda a,*a, b, **c, **d: None

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> lambda a=1,/,**b,/,c: None

Traceback (most recent call last):

SyntaxError: parameters cannot follow var-keyword parameter

>>> lambda *b,*d: None

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> lambda a,*b,c,*d,*e,c: None

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> lambda a,b,/,c,*b,c,*d,*e,c: None

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> lambda a,b,/,c,*b,c,*d,**e: None

Traceback (most recent call last):

SyntaxError: * may appear only once

>>> lambda a=1,d=,c: None

Traceback (most recent call last):

SyntaxError: expected default value expression

>>> lambda a,d=,c: None

Traceback (most recent call last):

SyntaxError: expected default value expression

>>> lambda a,d=3,c: None

Traceback (most recent call last):

SyntaxError: parameter without a default follows parameter with a default

>>> lambda a,/,d=3,c: None

Traceback (most recent call last):

SyntaxError: parameter without a default follows parameter with a default

>>> import ast; ast.parse('''

... def f(

... *, # type: int

... a, # type: int

... ):

... pass

... ''', type_comments=True)

Traceback (most recent call last):

SyntaxError: bare * has associated type comment

From ast_for_funcdef():

>>> def None(x):

... pass

Traceback (most recent call last):

SyntaxError: invalid syntax

From ast_for_call():

>>> def f(it, *varargs, **kwargs):

... return list(it)

>>> L = range(10)

>>> f(x for x in L)

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

>>> f(x for x in L, 1)

Traceback (most recent call last):

SyntaxError: Generator expression must be parenthesized

>>> f(x for x in L, y=1)

Traceback (most recent call last):

SyntaxError: Generator expression must be parenthesized

>>> f(x for x in L, *[])

Traceback (most recent call last):

SyntaxError: Generator expression must be parenthesized

>>> f(x for x in L, **{})

Traceback (most recent call last):

SyntaxError: Generator expression must be parenthesized

>>> f(L, x for x in L)

Traceback (most recent call last):

SyntaxError: Generator expression must be parenthesized

>>> f(x for x in L, y for y in L)

Traceback (most recent call last):

SyntaxError: Generator expression must be parenthesized

>>> f(x for x in L,)

Traceback (most recent call last):

SyntaxError: Generator expression must be parenthesized

>>> f((x for x in L), 1)

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

>>> class C(x for x in L):

... pass

Traceback (most recent call last):

SyntaxError: invalid syntax

>>> def g(*args, **kwargs):

... print(args, sorted(kwargs.items()))

>>> g(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

... 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,

... 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55,

... 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73,

... 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91,

... 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107,

... 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121,

... 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135,

... 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149,

... 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163,

... 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177,

... 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,

... 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205,

... 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,

... 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233,

... 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247,

... 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261,

... 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275,

... 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289,

... 290, 291, 292, 293, 294, 295, 296, 297, 298, 299) # doctest: +ELLIPSIS

(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ..., 297, 298, 299) []

>>> g(a000=0, a001=1, a002=2, a003=3, a004=4, a005=5, a006=6, a007=7, a008=8,

... a009=9, a010=10, a011=11, a012=12, a013=13, a014=14, a015=15, a016=16,

... a017=17, a018=18, a019=19, a020=20, a021=21, a022=22, a023=23, a024=24,

... a025=25, a026=26, a027=27, a028=28, a029=29, a030=30, a031=31, a032=32,

... a033=33, a034=34, a035=35, a036=36, a037=37, a038=38, a039=39, a040=40,

... a041=41, a042=42, a043=43, a044=44, a045=45, a046=46, a047=47, a048=48,

... a049=49, a050=50, a051=51, a052=52, a053=53, a054=54, a055=55, a056=56,

... a057=57, a058=58, a059=59, a060=60, a061=61, a062=62, a063=63, a064=64,

... a065=65, a066=66, a067=67, a068=68, a069=69, a070=70, a071=71, a072=72,

... a073=73, a074=74, a075=75, a076=76, a077=77, a078=78, a079=79, a080=80,

... a081=81, a082=82, a083=83, a084=84, a085=85, a086=86, a087=87, a088=88,

... a089=89, a090=90, a091=91, a092=92, a093=93, a094=94, a095=95, a096=96,

... a097=97, a098=98, a099=99, a100=100, a101=101, a102=102, a103=103,

... a104=104, a105=105, a106=106, a107=107, a108=108, a109=109, a110=110,

... a111=111, a112=112, a113=113, a114=114, a115=115, a116=116, a117=117,

... a118=118, a119=119, a120=120, a121=121, a122=122, a123=123, a124=124,

... a125=125, a126=126, a127=127, a128=128, a129=129, a130=130, a131=131,

... a132=132, a133=133, a134=134, a135=135, a136=136, a137=137, a138=138,

... a139=139, a140=140, a141=141, a142=142, a143=143, a144=144, a145=145,

... a146=146, a147=147, a148=148, a149=149, a150=150, a151=151, a152=152,

... a153=153, a154=154, a155=155, a156=156, a157=157, a158=158, a159=159,

... a160=160, a161=161, a162=162, a163=163, a164=164, a165=165, a166=166,

... a167=167, a168=168, a169=169, a170=170, a171=171, a172=172, a173=173,

... a174=174, a175=175, a176=176, a177=177, a178=178, a179=179, a180=180,

... a181=181, a182=182, a183=183, a184=184, a185=185, a186=186, a187=187,

... a188=188, a189=189, a190=190, a191=191, a192=192, a193=193, a194=194,

... a195=195, a196=196, a197=197, a198=198, a199=199, a200=200, a201=201,

... a202=202, a203=203, a204=204, a205=205, a206=206, a207=207, a208=208,

... a209=209, a210=210, a211=211, a212=212, a213=213, a214=214, a215=215,

... a216=216, a217=217, a218=218, a219=219, a220=220, a221=221, a222=222,

... a223=223, a224=224, a225=225, a226=226, a227=227, a228=228, a229=229,

... a230=230, a231=231, a232=232, a233=233, a234=234, a235=235, a236=236,

... a237=237, a238=238, a239=239, a240=240, a241=241, a242=242, a243=243,

... a244=244, a245=245, a246=246, a247=247, a248=248, a249=249, a250=250,

... a251=251, a252=252, a253=253, a254=254, a255=255, a256=256, a257=257,

... a258=258, a259=259, a260=260, a261=261, a262=262, a263=263, a264=264,

... a265=265, a266=266, a267=267, a268=268, a269=269, a270=270, a271=271,

... a272=272, a273=273, a274=274, a275=275, a276=276, a277=277, a278=278,

... a279=279, a280=280, a281=281, a282=282, a283=283, a284=284, a285=285,

... a286=286, a287=287, a288=288, a289=289, a290=290, a291=291, a292=292,

... a293=293, a294=294, a295=295, a296=296, a297=297, a298=298, a299=299)

... # doctest: +ELLIPSIS

() [('a000', 0), ('a001', 1), ('a002', 2), ..., ('a298', 298), ('a299', 299)]

>>> class C:

... def meth(self, *args):

... return args

>>> obj = C()

>>> obj.meth(

... 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

... 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,

... 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55,

... 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73,

... 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91,

... 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107,

... 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121,

... 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135,

... 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149,

... 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163,

... 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177,

... 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,

... 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205,

... 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,

... 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233,

... 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247,

... 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261,

... 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275,

... 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289,

... 290, 291, 292, 293, 294, 295, 296, 297, 298, 299) # doctest: +ELLIPSIS

(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ..., 297, 298, 299)

>>> f(lambda x: x[0] = 3)

Traceback (most recent call last):

SyntaxError: expression cannot contain assignment, perhaps you meant "=="?

# Check that this error doesn't trigger for names:

>>> f(a={x: for x in {}})

Traceback (most recent call last):

SyntaxError: invalid syntax

The grammar accepts any test (basically, any expression) in the

keyword slot of a call site. Test a few different options.

>>> f(x()=2)

Traceback (most recent call last):

SyntaxError: expression cannot contain assignment, perhaps you meant "=="?

>>> f(a or b=1)

Traceback (most recent call last):

SyntaxError: expression cannot contain assignment, perhaps you meant "=="?

>>> f(x.y=1)

Traceback (most recent call last):

SyntaxError: expression cannot contain assignment, perhaps you meant "=="?

>>> f((x)=2)

Traceback (most recent call last):

SyntaxError: expression cannot contain assignment, perhaps you meant "=="?

>>> f(True=1)

Traceback (most recent call last):

SyntaxError: cannot assign to True

>>> f(False=1)

Traceback (most recent call last):

SyntaxError: cannot assign to False

>>> f(None=1)

Traceback (most recent call last):

SyntaxError: cannot assign to None

>>> f(__debug__=1)

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> __debug__: int

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> x.__debug__: int

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> f(a=)

Traceback (most recent call last):

SyntaxError: expected argument value expression

>>> f(a, b, c=)

Traceback (most recent call last):

SyntaxError: expected argument value expression

>>> f(a, b, c=, d)

Traceback (most recent call last):

SyntaxError: expected argument value expression

>>> f(*args=[0])

Traceback (most recent call last):

SyntaxError: cannot assign to iterable argument unpacking

>>> f(a, b, *args=[0])

Traceback (most recent call last):

SyntaxError: cannot assign to iterable argument unpacking

>>> f(**kwargs={'a': 1})

Traceback (most recent call last):

SyntaxError: cannot assign to keyword argument unpacking

>>> f(a, b, *args, **kwargs={'a': 1})

Traceback (most recent call last):

SyntaxError: cannot assign to keyword argument unpacking

More set_context():

>>> (x for x in x) += 1

Traceback (most recent call last):

SyntaxError: 'generator expression' is an illegal expression for augmented assignment

>>> None += 1

Traceback (most recent call last):

SyntaxError: 'None' is an illegal expression for augmented assignment

>>> __debug__ += 1

Traceback (most recent call last):

SyntaxError: cannot assign to __debug__

>>> f() += 1

Traceback (most recent call last):

SyntaxError: 'function call' is an illegal expression for augmented assignment

Test control flow in finally

continue in for loop under finally should be ok.

>>> def test():

... try:

... pass

... finally:

... for abc in range(10):

... continue

... print(abc)

>>> test()

9

break in for loop under finally should be ok.

>>> def test():

... try:

... pass

... finally:

... for abc in range(10):

... break

... print(abc)

>>> test()

0

return in function under finally should be ok.

>>> def test():

... try:

... pass

... finally:

... def f():

... return 42

... print(f())

>>> test()

42

combine for loop and function def

return in function under finally should be ok.

>>> def test():

... try:

... pass

... finally:

... for i in range(10):

... def f():

... return 42

... print(f())

>>> test()

42

>>> def test():

... try:

... pass

... finally:

... def f():

... for i in range(10):

... return 42

... print(f())

>>> test()

42

A continue outside loop should not be allowed.

>>> def foo():

... try:

... continue

... finally:

... pass

Traceback (most recent call last):

...

SyntaxError: 'continue' not properly in loop

There is one test for a break that is not in a loop. The compiler

uses a single data structure to keep track of try-finally and loops,

so we need to be sure that a break is actually inside a loop. If it

isn't, there should be a syntax error.

>>> try:

... print(1)

... break

... print(2)

... finally:

... print(3)

Traceback (most recent call last):

...

SyntaxError: 'break' outside loop

elif can't come after an else.

>>> if a % 2 == 0:

... pass

... else:

... pass

... elif a % 2 == 1:

... pass

Traceback (most recent call last):

...

SyntaxError: 'elif' block follows an 'else' block

Misuse of the nonlocal and global statement can lead to a few unique syntax errors.

>>> def f():

... print(x)

... global x

Traceback (most recent call last):

...

SyntaxError: name 'x' is used prior to global declaration

>>> def f():

... x = 1

... global x

Traceback (most recent call last):

...

SyntaxError: name 'x' is assigned to before global declaration

>>> def f(x):

... global x

Traceback (most recent call last):

...

SyntaxError: name 'x' is parameter and global

>>> def f():

... x = 1

... def g():

... print(x)

... nonlocal x

Traceback (most recent call last):

...

SyntaxError: name 'x' is used prior to nonlocal declaration

>>> def f():

... x = 1

... def g():

... x = 2

... nonlocal x

Traceback (most recent call last):

...