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bpo-43224: Implement PEP 646 grammar changes #31018

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merged 17 commits into from Mar 26, 2022
+3,056 −2,128
Merged

bpo-43224: Implement PEP 646 grammar changes #31018

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7ecb7ba
bpo-43224: Implement PEP 646 grammar changes
mrahtz Jan 30, 2022
c0531ec
Add tests for del
mrahtz Jan 30, 2022
479c175
Tweak news to better fit in with other PRs
mrahtz Jan 30, 2022
091ceeb
Move error cases into test_syntax
mrahtz Feb 13, 2022
f1c9c77
Add an extra failure test
mrahtz Feb 14, 2022
c8d2534
Add more tests combining slicing with starring
mrahtz Mar 17, 2022
5df1e97
Fix ast representation of slices combined with starring
mrahtz Mar 17, 2022
677a326
Fix broken test in test_unparse
mrahtz Mar 17, 2022
1543785
Add a check_src_roundtrip test for "a[1:2, *a]"
mrahtz Mar 17, 2022
e1ab6ea
fix whitespace (make patchcheck)
JelleZijlstra Mar 23, 2022
18e7fa7
Merge remote-tracking branch 'upstream/main' into pep646-grammar
JelleZijlstra Mar 23, 2022
72dd8b9
Add tests for AST changes
mrahtz Mar 24, 2022
80bb5fa
Fix C unpack
mrahtz Mar 24, 2022
fbfd5b1
Fix typing.get_type_hints on variadic annotation
mrahtz Mar 24, 2022
816098c
Fix typo
mrahtz Mar 24, 2022
8962d26
Remove debug print
mrahtz Mar 25, 2022
973e9cc
Fix potential shadowing in ForwardRef
mrahtz Mar 25, 2022
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9 changes: 8 additions & 1 deletion Grammar/python.gram
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Expand Up @@ -308,6 +308,8 @@ slash_with_default[SlashWithDefault*]:
star_etc[StarEtc*]:
| '*' a=param_no_default b=param_maybe_default* c=[kwds] {
_PyPegen_star_etc(p, a, b, c) }
| '*' a=param_no_default_star_annotation b=param_maybe_default* c=[kwds] {
_PyPegen_star_etc(p, a, b, c) }
| '*' ',' b=param_maybe_default+ c=[kwds] {
_PyPegen_star_etc(p, NULL, b, c) }
| a=kwds { _PyPegen_star_etc(p, NULL, NULL, a) }
Expand All @@ -331,14 +333,19 @@ kwds[arg_ty]: '**' a=param_no_default { a }
param_no_default[arg_ty]:
| a=param ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
| a=param tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
param_no_default_star_annotation[arg_ty]:
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| a=param_star_annotation ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
| a=param_star_annotation tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
param_with_default[NameDefaultPair*]:
| a=param c=default ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
| a=param c=default tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
param_maybe_default[NameDefaultPair*]:
| a=param c=default? ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
| a=param c=default? tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
param[arg_ty]: a=NAME b=annotation? { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
param_star_annotation[arg_ty]: a=NAME b=star_annotation { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
annotation[expr_ty]: ':' a=expression { a }
star_annotation[expr_ty]: ':' a=star_expression { a }
default[expr_ty]: '=' a=expression { a }

# If statement
Expand Down Expand Up @@ -780,7 +787,7 @@ primary[expr_ty]:

slices[expr_ty]:
| a=slice !',' { a }
| a[asdl_expr_seq*]=','.slice+ [','] { _PyAST_Tuple(a, Load, EXTRA) }
| a[asdl_expr_seq*]=','.(slice | starred_expression)+ [','] { _PyAST_Tuple(a, Load, EXTRA) }
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slice[expr_ty]:
| a=[expression] ':' b=[expression] c=[':' d=[expression] { d }] { _PyAST_Slice(a, b, c, EXTRA) }
Expand Down
25 changes: 24 additions & 1 deletion Lib/test/test_ast.py
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Expand Up @@ -13,7 +13,7 @@
from test import support

def to_tuple(t):
if t is None or isinstance(t, (str, int, complex)):
if t is None or isinstance(t, (str, int, complex)) or t is Ellipsis:
return t
elif isinstance(t, list):
return [to_tuple(e) for e in t]
Expand Down Expand Up @@ -46,10 +46,20 @@ def to_tuple(t):
"def f(a=0): pass",
# FunctionDef with varargs
"def f(*args): pass",
# FunctionDef with varargs as TypeVarTuple
"def f(*args: *Ts): pass",
# FunctionDef with varargs as unpacked Tuple
"def f(*args: *tuple[int, ...]): pass",
# FunctionDef with varargs as unpacked Tuple *and* TypeVarTuple
"def f(*args: *tuple[int, *Ts]): pass",
# FunctionDef with kwargs
"def f(**kwargs): pass",
# FunctionDef with all kind of args and docstring
"def f(a, b=1, c=None, d=[], e={}, *args, f=42, **kwargs): 'doc for f()'",
# FunctionDef with type annotation on return involving unpacking
"def f() -> tuple[*Ts]: pass",
"def f() -> tuple[int, *Ts]: pass",
"def f() -> tuple[int, *tuple[int, ...]]: pass",
# ClassDef
"class C:pass",
# ClassDef with docstring
Expand All @@ -65,6 +75,10 @@ def to_tuple(t):
"a,b = c",
"(a,b) = c",
"[a,b] = c",
# AnnAssign with unpacked types
"x: tuple[*Ts]",
"x: tuple[int, *Ts]",
"x: tuple[int, *tuple[str, ...]]",
# AugAssign
"v += 1",
# For
Expand Down Expand Up @@ -2316,8 +2330,14 @@ def main():
('Module', [('FunctionDef', (1, 0, 1, 14), 'f', ('arguments', [], [('arg', (1, 6, 1, 7), 'a', None, None)], None, [], [], None, []), [('Pass', (1, 10, 1, 14))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 16), 'f', ('arguments', [], [('arg', (1, 6, 1, 7), 'a', None, None)], None, [], [], None, [('Constant', (1, 8, 1, 9), 0, None)]), [('Pass', (1, 12, 1, 16))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 18), 'f', ('arguments', [], [], ('arg', (1, 7, 1, 11), 'args', None, None), [], [], None, []), [('Pass', (1, 14, 1, 18))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 23), 'f', ('arguments', [], [], ('arg', (1, 7, 1, 16), 'args', ('Starred', (1, 13, 1, 16), ('Name', (1, 14, 1, 16), 'Ts', ('Load',)), ('Load',)), None), [], [], None, []), [('Pass', (1, 19, 1, 23))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 36), 'f', ('arguments', [], [], ('arg', (1, 7, 1, 29), 'args', ('Starred', (1, 13, 1, 29), ('Subscript', (1, 14, 1, 29), ('Name', (1, 14, 1, 19), 'tuple', ('Load',)), ('Tuple', (1, 20, 1, 28), [('Name', (1, 20, 1, 23), 'int', ('Load',)), ('Constant', (1, 25, 1, 28), Ellipsis, None)], ('Load',)), ('Load',)), ('Load',)), None), [], [], None, []), [('Pass', (1, 32, 1, 36))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 36), 'f', ('arguments', [], [], ('arg', (1, 7, 1, 29), 'args', ('Starred', (1, 13, 1, 29), ('Subscript', (1, 14, 1, 29), ('Name', (1, 14, 1, 19), 'tuple', ('Load',)), ('Tuple', (1, 20, 1, 28), [('Name', (1, 20, 1, 23), 'int', ('Load',)), ('Starred', (1, 25, 1, 28), ('Name', (1, 26, 1, 28), 'Ts', ('Load',)), ('Load',))], ('Load',)), ('Load',)), ('Load',)), None), [], [], None, []), [('Pass', (1, 32, 1, 36))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 21), 'f', ('arguments', [], [], None, [], [], ('arg', (1, 8, 1, 14), 'kwargs', None, None), []), [('Pass', (1, 17, 1, 21))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 71), 'f', ('arguments', [], [('arg', (1, 6, 1, 7), 'a', None, None), ('arg', (1, 9, 1, 10), 'b', None, None), ('arg', (1, 14, 1, 15), 'c', None, None), ('arg', (1, 22, 1, 23), 'd', None, None), ('arg', (1, 28, 1, 29), 'e', None, None)], ('arg', (1, 35, 1, 39), 'args', None, None), [('arg', (1, 41, 1, 42), 'f', None, None)], [('Constant', (1, 43, 1, 45), 42, None)], ('arg', (1, 49, 1, 55), 'kwargs', None, None), [('Constant', (1, 11, 1, 12), 1, None), ('Constant', (1, 16, 1, 20), None, None), ('List', (1, 24, 1, 26), [], ('Load',)), ('Dict', (1, 30, 1, 32), [], [])]), [('Expr', (1, 58, 1, 71), ('Constant', (1, 58, 1, 71), 'doc for f()', None))], [], None, None)], []),
('Module', [('FunctionDef', (1, 0, 1, 27), 'f', ('arguments', [], [], None, [], [], None, []), [('Pass', (1, 23, 1, 27))], [], ('Subscript', (1, 11, 1, 21), ('Name', (1, 11, 1, 16), 'tuple', ('Load',)), ('Tuple', (1, 17, 1, 20), [('Starred', (1, 17, 1, 20), ('Name', (1, 18, 1, 20), 'Ts', ('Load',)), ('Load',))], ('Load',)), ('Load',)), None)], []),
('Module', [('FunctionDef', (1, 0, 1, 32), 'f', ('arguments', [], [], None, [], [], None, []), [('Pass', (1, 28, 1, 32))], [], ('Subscript', (1, 11, 1, 26), ('Name', (1, 11, 1, 16), 'tuple', ('Load',)), ('Tuple', (1, 17, 1, 25), [('Name', (1, 17, 1, 20), 'int', ('Load',)), ('Starred', (1, 22, 1, 25), ('Name', (1, 23, 1, 25), 'Ts', ('Load',)), ('Load',))], ('Load',)), ('Load',)), None)], []),
('Module', [('FunctionDef', (1, 0, 1, 45), 'f', ('arguments', [], [], None, [], [], None, []), [('Pass', (1, 41, 1, 45))], [], ('Subscript', (1, 11, 1, 39), ('Name', (1, 11, 1, 16), 'tuple', ('Load',)), ('Tuple', (1, 17, 1, 38), [('Name', (1, 17, 1, 20), 'int', ('Load',)), ('Starred', (1, 22, 1, 38), ('Subscript', (1, 23, 1, 38), ('Name', (1, 23, 1, 28), 'tuple', ('Load',)), ('Tuple', (1, 29, 1, 37), [('Name', (1, 29, 1, 32), 'int', ('Load',)), ('Constant', (1, 34, 1, 37), Ellipsis, None)], ('Load',)), ('Load',)), ('Load',))], ('Load',)), ('Load',)), None)], []),
('Module', [('ClassDef', (1, 0, 1, 12), 'C', [], [], [('Pass', (1, 8, 1, 12))], [])], []),
('Module', [('ClassDef', (1, 0, 1, 32), 'C', [], [], [('Expr', (1, 9, 1, 32), ('Constant', (1, 9, 1, 32), 'docstring for class C', None))], [])], []),
('Module', [('ClassDef', (1, 0, 1, 21), 'C', [('Name', (1, 8, 1, 14), 'object', ('Load',))], [], [('Pass', (1, 17, 1, 21))], [])], []),
Expand All @@ -2327,6 +2347,9 @@ def main():
('Module', [('Assign', (1, 0, 1, 7), [('Tuple', (1, 0, 1, 3), [('Name', (1, 0, 1, 1), 'a', ('Store',)), ('Name', (1, 2, 1, 3), 'b', ('Store',))], ('Store',))], ('Name', (1, 6, 1, 7), 'c', ('Load',)), None)], []),
('Module', [('Assign', (1, 0, 1, 9), [('Tuple', (1, 0, 1, 5), [('Name', (1, 1, 1, 2), 'a', ('Store',)), ('Name', (1, 3, 1, 4), 'b', ('Store',))], ('Store',))], ('Name', (1, 8, 1, 9), 'c', ('Load',)), None)], []),
('Module', [('Assign', (1, 0, 1, 9), [('List', (1, 0, 1, 5), [('Name', (1, 1, 1, 2), 'a', ('Store',)), ('Name', (1, 3, 1, 4), 'b', ('Store',))], ('Store',))], ('Name', (1, 8, 1, 9), 'c', ('Load',)), None)], []),
('Module', [('AnnAssign', (1, 0, 1, 13), ('Name', (1, 0, 1, 1), 'x', ('Store',)), ('Subscript', (1, 3, 1, 13), ('Name', (1, 3, 1, 8), 'tuple', ('Load',)), ('Tuple', (1, 9, 1, 12), [('Starred', (1, 9, 1, 12), ('Name', (1, 10, 1, 12), 'Ts', ('Load',)), ('Load',))], ('Load',)), ('Load',)), None, 1)], []),
('Module', [('AnnAssign', (1, 0, 1, 18), ('Name', (1, 0, 1, 1), 'x', ('Store',)), ('Subscript', (1, 3, 1, 18), ('Name', (1, 3, 1, 8), 'tuple', ('Load',)), ('Tuple', (1, 9, 1, 17), [('Name', (1, 9, 1, 12), 'int', ('Load',)), ('Starred', (1, 14, 1, 17), ('Name', (1, 15, 1, 17), 'Ts', ('Load',)), ('Load',))], ('Load',)), ('Load',)), None, 1)], []),
('Module', [('AnnAssign', (1, 0, 1, 31), ('Name', (1, 0, 1, 1), 'x', ('Store',)), ('Subscript', (1, 3, 1, 31), ('Name', (1, 3, 1, 8), 'tuple', ('Load',)), ('Tuple', (1, 9, 1, 30), [('Name', (1, 9, 1, 12), 'int', ('Load',)), ('Starred', (1, 14, 1, 30), ('Subscript', (1, 15, 1, 30), ('Name', (1, 15, 1, 20), 'tuple', ('Load',)), ('Tuple', (1, 21, 1, 29), [('Name', (1, 21, 1, 24), 'str', ('Load',)), ('Constant', (1, 26, 1, 29), Ellipsis, None)], ('Load',)), ('Load',)), ('Load',))], ('Load',)), ('Load',)), None, 1)], []),
('Module', [('AugAssign', (1, 0, 1, 6), ('Name', (1, 0, 1, 1), 'v', ('Store',)), ('Add',), ('Constant', (1, 5, 1, 6), 1, None))], []),
('Module', [('For', (1, 0, 1, 15), ('Name', (1, 4, 1, 5), 'v', ('Store',)), ('Name', (1, 9, 1, 10), 'v', ('Load',)), [('Pass', (1, 11, 1, 15))], [], None)], []),
('Module', [('While', (1, 0, 1, 12), ('Name', (1, 6, 1, 7), 'v', ('Load',)), [('Pass', (1, 8, 1, 12))], [])], []),
Expand Down
286 changes: 286 additions & 0 deletions Lib/test/test_pep646_syntax.py
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@@ -0,0 +1,286 @@
doctests = """

Setup

>>> class AClass:
... def __init__(self):
... self._setitem_name = None
... self._setitem_val = None
... self._delitem_name = None
... def __setitem__(self, name, val):
... self._delitem_name = None
... self._setitem_name = name
... self._setitem_val = val
... def __repr__(self):
... if self._setitem_name is not None:
... return f"A[{self._setitem_name}]={self._setitem_val}"
... elif self._delitem_name is not None:
... return f"delA[{self._delitem_name}]"
... def __getitem__(self, name):
... return ParameterisedA(name)
... def __delitem__(self, name):
... self._setitem_name = None
... self._delitem_name = name
...
>>> class ParameterisedA:
... def __init__(self, name):
... self._name = name
... def __repr__(self):
... return f"A[{self._name}]"
... def __iter__(self):
... for p in self._name:
... yield p
>>> class B:
... def __iter__(self):
... yield StarredB()
... def __repr__(self):
... return "B"
>>> class StarredB:
... def __repr__(self):
... return "StarredB"
>>> A = AClass()
>>> b = B()

Slices that are supposed to work, starring our custom B class

>>> A[*b]
A[(StarredB,)]
>>> A[*b] = 1; A
A[(StarredB,)]=1
>>> del A[*b]; A
delA[(StarredB,)]

>>> A[*b, *b]
A[(StarredB, StarredB)]
>>> A[*b, *b] = 1; A
A[(StarredB, StarredB)]=1
>>> del A[*b, *b]; A
delA[(StarredB, StarredB)]

>>> A[b, *b]
A[(B, StarredB)]
>>> A[b, *b] = 1; A
A[(B, StarredB)]=1
>>> del A[b, *b]; A
delA[(B, StarredB)]

>>> A[*b, b]
A[(StarredB, B)]
>>> A[*b, b] = 1; A
A[(StarredB, B)]=1
>>> del A[*b, b]; A
delA[(StarredB, B)]

>>> A[b, b, *b]
A[(B, B, StarredB)]
>>> A[b, b, *b] = 1; A
A[(B, B, StarredB)]=1
>>> del A[b, b, *b]; A
delA[(B, B, StarredB)]

>>> A[*b, b, b]
A[(StarredB, B, B)]
>>> A[*b, b, b] = 1; A
A[(StarredB, B, B)]=1
>>> del A[*b, b, b]; A
delA[(StarredB, B, B)]

>>> A[b, *b, b]
A[(B, StarredB, B)]
>>> A[b, *b, b] = 1; A
A[(B, StarredB, B)]=1
>>> del A[b, *b, b]; A
delA[(B, StarredB, B)]

>>> A[b, b, *b, b]
A[(B, B, StarredB, B)]
>>> A[b, b, *b, b] = 1; A
A[(B, B, StarredB, B)]=1
>>> del A[b, b, *b, b]; A
delA[(B, B, StarredB, B)]

>>> A[b, *b, b, b]
A[(B, StarredB, B, B)]
>>> A[b, *b, b, b] = 1; A
A[(B, StarredB, B, B)]=1
>>> del A[b, *b, b, b]; A
delA[(B, StarredB, B, B)]

>>> A[A[b, *b, b]]
A[A[(B, StarredB, B)]]
>>> A[A[b, *b, b]] = 1; A
A[A[(B, StarredB, B)]]=1
>>> del A[A[b, *b, b]]; A
delA[A[(B, StarredB, B)]]

>>> A[*A[b, *b, b]]
A[(B, StarredB, B)]
>>> A[*A[b, *b, b]] = 1; A
A[(B, StarredB, B)]=1
>>> del A[*A[b, *b, b]]; A
delA[(B, StarredB, B)]

>>> A[b, ...]
A[(B, Ellipsis)]
>>> A[b, ...] = 1; A
A[(B, Ellipsis)]=1
>>> del A[b, ...]; A
delA[(B, Ellipsis)]

>>> A[*A[b, ...]]
A[(B, Ellipsis)]
>>> A[*A[b, ...]] = 1; A
A[(B, Ellipsis)]=1
>>> del A[*A[b, ...]]; A
delA[(B, Ellipsis)]

Slices that are supposed to work, starring a list

>>> l = [1, 2, 3]

>>> A[*l]
A[(1, 2, 3)]
>>> A[*l] = 1; A
A[(1, 2, 3)]=1
>>> del A[*l]; A
delA[(1, 2, 3)]

>>> A[*l, 4]
A[(1, 2, 3, 4)]
>>> A[*l, 4] = 1; A
A[(1, 2, 3, 4)]=1
>>> del A[*l, 4]; A
delA[(1, 2, 3, 4)]

>>> A[0, *l]
A[(0, 1, 2, 3)]
>>> A[0, *l] = 1; A
A[(0, 1, 2, 3)]=1
>>> del A[0, *l]; A
delA[(0, 1, 2, 3)]

>>> A[1:2, *l]
A[(slice(1, 2, None), 1, 2, 3)]
>>> A[1:2, *l] = 1; A
A[(slice(1, 2, None), 1, 2, 3)]=1
>>> del A[1:2, *l]; A
delA[(slice(1, 2, None), 1, 2, 3)]

>>> repr(A[1:2, *l]) == repr(A[1:2, 1, 2, 3])
True

Slices that are supposed to work, starring a tuple

>>> t = (1, 2, 3)

>>> A[*t]
A[(1, 2, 3)]
>>> A[*t] = 1; A
A[(1, 2, 3)]=1
>>> del A[*t]; A
delA[(1, 2, 3)]

>>> A[*t, 4]
A[(1, 2, 3, 4)]
>>> A[*t, 4] = 1; A
A[(1, 2, 3, 4)]=1
>>> del A[*t, 4]; A
delA[(1, 2, 3, 4)]

>>> A[0, *t]
A[(0, 1, 2, 3)]
>>> A[0, *t] = 1; A
A[(0, 1, 2, 3)]=1
>>> del A[0, *t]; A
delA[(0, 1, 2, 3)]

>>> A[1:2, *t]
A[(slice(1, 2, None), 1, 2, 3)]
>>> A[1:2, *t] = 1; A
A[(slice(1, 2, None), 1, 2, 3)]=1
>>> del A[1:2, *t]; A
delA[(slice(1, 2, None), 1, 2, 3)]

>>> repr(A[1:2, *t]) == repr(A[1:2, 1, 2, 3])
True

Starring an expression (rather than a name) in a slice

>>> def returns_list():
... return [1, 2, 3]

>>> A[returns_list()]
A[[1, 2, 3]]
>>> A[returns_list()] = 1; A
A[[1, 2, 3]]=1
>>> del A[returns_list()]; A
delA[[1, 2, 3]]

>>> A[returns_list(), 4]
A[([1, 2, 3], 4)]
>>> A[returns_list(), 4] = 1; A
A[([1, 2, 3], 4)]=1
>>> del A[returns_list(), 4]; A
delA[([1, 2, 3], 4)]

>>> A[*returns_list()]
A[(1, 2, 3)]
>>> A[*returns_list()] = 1; A
A[(1, 2, 3)]=1
>>> del A[*returns_list()]; A
delA[(1, 2, 3)]

>>> A[*returns_list(), 4]
A[(1, 2, 3, 4)]
>>> A[*returns_list(), 4] = 1; A
A[(1, 2, 3, 4)]=1
>>> del A[*returns_list(), 4]; A
delA[(1, 2, 3, 4)]

>>> A[0, *returns_list()]
A[(0, 1, 2, 3)]
>>> A[0, *returns_list()] = 1; A
A[(0, 1, 2, 3)]=1
>>> del A[0, *returns_list()]; A
delA[(0, 1, 2, 3)]

>>> A[*returns_list(), *returns_list()]
A[(1, 2, 3, 1, 2, 3)]
>>> A[*returns_list(), *returns_list()] = 1; A
A[(1, 2, 3, 1, 2, 3)]=1
>>> del A[*returns_list(), *returns_list()]; A
delA[(1, 2, 3, 1, 2, 3)]

*args annotated as starred expression

>>> def f1(*args: *b): pass
>>> f1.__annotations__
{'args': StarredB}

>>> def f2(*args: *b, arg1): pass
>>> f2.__annotations__
{'args': StarredB}

>>> def f3(*args: *b, arg1: int): pass
>>> f3.__annotations__
{'args': StarredB, 'arg1': <class 'int'>}

>>> def f4(*args: *b, arg1: int = 2): pass
>>> f4.__annotations__
{'args': StarredB, 'arg1': <class 'int'>}

>>> def f5(*args: *b = (1,)): pass
Traceback (most recent call last):
...
SyntaxError: invalid syntax
"""

__test__ = {'doctests' : doctests}

def test_main(verbose=False):
from test import support
from test import test_pep646_syntax
support.run_doctest(test_pep646_syntax, verbose)

if __name__ == "__main__":
test_main(verbose=True)