Merge pull request #518 from python/main

sthagen · web-flow · commit 3fac25072a58 · 2021-07-14T08:45:42.000+02:00
Sync Fork from Upstream Repo
diff --git a/Doc/library/bz2.rst b/Doc/library/bz2.rst
@@ -325,3 +325,8 @@ Writing and reading a bzip2-compressed file in binary mode:
     ...     content = f.read()
     >>> content == data  # Check equality to original object after round-trip
     True
+
+.. testcleanup::
+
+   import os
+   os.remove("myfile.bz2")
diff --git a/Doc/library/configparser.rst b/Doc/library/configparser.rst
@@ -46,6 +46,11 @@ can be customized by end users easily.
 
    import configparser
 
+.. testcleanup::
+
+   import os
+   os.remove("example.ini")
+
 
 Quick Start
 -----------
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
@@ -391,6 +391,9 @@ I/O Base Classes
       to control the number of lines read: no more lines will be read if the
       total size (in bytes/characters) of all lines so far exceeds *hint*.
 
+      *hint* values of ``0`` or less, as well as ``None``, are treated as no
+      hint.
+
       Note that it's already possible to iterate on file objects using ``for
       line in file: ...`` without calling ``file.readlines()``.
 
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
@@ -218,9 +218,9 @@ A comprehension in an :keyword:`!async def` function may consist of either a
 :keyword:`!for` or :keyword:`!async for` clause following the leading
 expression, may contain additional :keyword:`!for` or :keyword:`!async for`
 clauses, and may also use :keyword:`await` expressions.
-If a comprehension contains either :keyword:`!async for` clauses
-or :keyword:`!await` expressions it is called an
-:dfn:`asynchronous comprehension`.  An asynchronous comprehension may
+If a comprehension contains either :keyword:`!async for` clauses or
+:keyword:`!await` expressions or other asynchronous comprehensions it is called
+an :dfn:`asynchronous comprehension`.  An asynchronous comprehension may
 suspend the execution of the coroutine function in which it appears.
 See also :pep:`530`.
 
@@ -230,6 +230,11 @@ See also :pep:`530`.
 .. versionchanged:: 3.8
    ``yield`` and ``yield from`` prohibited in the implicitly nested scope.
 
+.. versionchanged:: 3.11
+   Asynchronous comprehensions are now allowed inside comprehensions in
+   asynchronous functions. Outer comprehensions implicitly become
+   asynchronous.
+
 
 .. _lists:
 
diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
@@ -148,16 +148,19 @@ See :pep:`657` for more details. (Contributed by Pablo Galindo, Batuhan Taskaya
 and Ammar Askar in :issue:`43950`.)
 
 
-
 Other Language Changes
 ======================
 
-A :exc:`TypeError` is now raised instead of an :exc:`AttributeError` in
-:meth:`contextlib.ExitStack.enter_context` and
-:meth:`contextlib.AsyncExitStack.enter_async_context` for objects which do not
-support the :term:`context manager` or :term:`asynchronous context manager`
-protocols correspondingly.
-(Contributed by Serhiy Storchaka in :issue:`44471`.)
+* Asynchronous comprehensions are now allowed inside comprehensions in
+  asynchronous functions. Outer comprehensions implicitly become
+  asynchronous. (Contributed by Serhiy Storchaka in :issue:`33346`.)
+
+* A :exc:`TypeError` is now raised instead of an :exc:`AttributeError` in
+  :meth:`contextlib.ExitStack.enter_context` and
+  :meth:`contextlib.AsyncExitStack.enter_async_context` for objects which do not
+  support the :term:`context manager` or :term:`asynchronous context manager`
+  protocols correspondingly.
+  (Contributed by Serhiy Storchaka in :issue:`44471`.)
 
 * A :exc:`TypeError` is now raised instead of an :exc:`AttributeError` in
   :keyword:`with` and :keyword:`async with` statements for objects which do not
diff --git a/Lib/configparser.py b/Lib/configparser.py
@@ -563,7 +563,7 @@ class RawConfigParser(MutableMapping):
     # Regular expressions for parsing section headers and options
     _SECT_TMPL = r"""
         \[                                 # [
-        (?P<header>[^]]+)                  # very permissive!
+        (?P<header>.+)                     # very permissive!
         \]                                 # ]
         """
     _OPT_TMPL = r"""
diff --git a/Lib/inspect.py b/Lib/inspect.py
@@ -2096,10 +2096,6 @@ def _signature_fromstr(cls, obj, s, skip_bound_arg=True):
     """Private helper to parse content of '__text_signature__'
     and return a Signature based on it.
     """
-    # Lazy import ast because it's relatively heavy and
-    # it's not used for other than this function.
-    import ast
-
     Parameter = cls._parameter_cls
 
     clean_signature, self_parameter, last_positional_only = \
diff --git a/Lib/lib2to3/btm_utils.py b/Lib/lib2to3/btm_utils.py
@@ -220,7 +220,6 @@ def reduce_tree(node, parent=None):
             else:
                 #TODO: handle {min, max} repeaters
                 raise NotImplementedError
-                pass
 
         #add children
         if details_node and new_node is not None:
diff --git a/Lib/multiprocessing/managers.py b/Lib/multiprocessing/managers.py
@@ -1337,7 +1337,6 @@ def __init__(self, *args, **kwargs):
 
         def __del__(self):
             util.debug(f"{self.__class__.__name__}.__del__ by pid {getpid()}")
-            pass
 
         def get_server(self):
             'Better than monkeypatching for now; merge into Server ultimately'
diff --git a/Lib/platform.py b/Lib/platform.py
@@ -280,6 +280,7 @@ def _syscmd_ver(system='', release='', version='',
     for cmd in ('ver', 'command /c ver', 'cmd /c ver'):
         try:
             info = subprocess.check_output(cmd,
+                                           stdin=subprocess.DEVNULL,
                                            stderr=subprocess.DEVNULL,
                                            text=True,
                                            shell=True)
diff --git a/Lib/telnetlib.py b/Lib/telnetlib.py
@@ -489,7 +489,6 @@ def process_rawq(self):
         except EOFError: # raised by self.rawq_getchar()
             self.iacseq = b'' # Reset on EOF
             self.sb = 0
-            pass
         self.cookedq = self.cookedq + buf[0]
         self.sbdataq = self.sbdataq + buf[1]
 
diff --git a/Lib/test/test_configparser.py b/Lib/test/test_configparser.py
@@ -79,6 +79,7 @@ def basic_test(self, cf):
              'Spacey Bar',
              'Spacey Bar From The Beginning',
              'Types',
+             'This One Has A ] In It',
              ]
 
         if self.allow_no_value:
@@ -130,6 +131,7 @@ def basic_test(self, cf):
         eq(cf.get('Types', 'float'), "0.44")
         eq(cf.getboolean('Types', 'boolean'), False)
         eq(cf.get('Types', '123'), 'strange but acceptable')
+        eq(cf.get('This One Has A ] In It', 'forks'), 'spoons')
         if self.allow_no_value:
             eq(cf.get('NoValue', 'option-without-value'), None)
 
@@ -320,6 +322,8 @@ def test_basic(self):
 float {0[0]} 0.44
 boolean {0[0]} NO
 123 {0[1]} strange but acceptable
+[This One Has A ] In It]
+  forks {0[0]} spoons
 """.format(self.delimiters, self.comment_prefixes)
         if self.allow_no_value:
             config_string += (
@@ -394,6 +398,9 @@ def test_basic_from_dict(self):
                 "boolean": False,
                 123: "strange but acceptable",
             },
+            "This One Has A ] In It": {
+                "forks": "spoons"
+            },
         }
         if self.allow_no_value:
             config.update({
diff --git a/Lib/test/test_coroutines.py b/Lib/test/test_coroutines.py
@@ -28,6 +28,12 @@ def __await__(self):
         yield self.value
 
 
+async def asynciter(iterable):
+    """Convert an iterable to an asynchronous iterator."""
+    for x in iterable:
+        yield x
+
+
 def run_async(coro):
     assert coro.__class__ in {types.GeneratorType, types.CoroutineType}
 
@@ -125,6 +131,11 @@ def bar():
                     for c in b]
             """,
 
+            """async def foo():
+                def bar():
+                 [[async for i in b] for b in els]
+            """,
+
             """async def foo():
                 def bar():
                  [i for i in els
@@ -200,6 +211,13 @@ def bar():
                  [i for i in els if await i]
             """,
 
+            """def bar():
+                 [[i async for i in a] for a in elts]
+            """,
+
+            """[[i async for i in a] for a in elts]
+            """,
+
             """async def foo():
                 await
             """,
@@ -2011,6 +2029,60 @@ async def f():
             run_async(f()),
             ([], {1: 1, 2: 2, 3: 3}))
 
+    def test_nested_comp(self):
+        async def run_list_inside_list():
+            return [[i + j async for i in asynciter([1, 2])] for j in [10, 20]]
+        self.assertEqual(
+            run_async(run_list_inside_list()),
+            ([], [[11, 12], [21, 22]]))
+
+        async def run_set_inside_list():
+            return [{i + j async for i in asynciter([1, 2])} for j in [10, 20]]
+        self.assertEqual(
+            run_async(run_set_inside_list()),
+            ([], [{11, 12}, {21, 22}]))
+
+        async def run_list_inside_set():
+            return {sum([i async for i in asynciter(range(j))]) for j in [3, 5]}
+        self.assertEqual(
+            run_async(run_list_inside_set()),
+            ([], {3, 10}))
+
+        async def run_dict_inside_dict():
+            return {j: {i: i + j async for i in asynciter([1, 2])} for j in [10, 20]}
+        self.assertEqual(
+            run_async(run_dict_inside_dict()),
+            ([], {10: {1: 11, 2: 12}, 20: {1: 21, 2: 22}}))
+
+        async def run_list_inside_gen():
+            gen = ([i + j async for i in asynciter([1, 2])] for j in [10, 20])
+            return [x async for x in gen]
+        self.assertEqual(
+            run_async(run_list_inside_gen()),
+            ([], [[11, 12], [21, 22]]))
+
+        async def run_gen_inside_list():
+            gens = [(i async for i in asynciter(range(j))) for j in [3, 5]]
+            return [x for g in gens async for x in g]
+        self.assertEqual(
+            run_async(run_gen_inside_list()),
+            ([], [0, 1, 2, 0, 1, 2, 3, 4]))
+
+        async def run_gen_inside_gen():
+            gens = ((i async for i in asynciter(range(j))) for j in [3, 5])
+            return [x for g in gens async for x in g]
+        self.assertEqual(
+            run_async(run_gen_inside_gen()),
+            ([], [0, 1, 2, 0, 1, 2, 3, 4]))
+
+        async def run_list_inside_list_inside_list():
+            return [[[i + j + k async for i in asynciter([1, 2])]
+                     for j in [10, 20]]
+                    for k in [100, 200]]
+        self.assertEqual(
+            run_async(run_list_inside_list_inside_list()),
+            ([], [[[111, 112], [121, 122]], [[211, 212], [221, 222]]]))
+
     def test_copy(self):
         async def func(): pass
         coro = func()
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
@@ -458,9 +458,15 @@ class testC(csv.excel):
         class testUni(csv.excel):
             delimiter = "\u039B"
 
+        class unspecified():
+            # A class to pass as dialect but with no dialect attributes.
+            pass
+
         csv.register_dialect('testC', testC)
         try:
             self.compare_dialect_123("1,2,3\r\n")
+            self.compare_dialect_123("1,2,3\r\n", dialect=None)
+            self.compare_dialect_123("1,2,3\r\n", dialect=unspecified)
             self.compare_dialect_123("1\t2\t3\r\n", testA)
             self.compare_dialect_123("1:2:3\r\n", dialect=testB())
             self.compare_dialect_123("1|2|3\r\n", dialect='testC')
diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py
@@ -43,8 +43,14 @@ def get_tk_patchlevel():
 class TkinterTest(unittest.TestCase):
 
     def testFlattenLen(self):
-        # flatten(<object with no length>)
+        # Object without length.
         self.assertRaises(TypeError, _tkinter._flatten, True)
+        # Object with length, but not sequence.
+        self.assertRaises(TypeError, _tkinter._flatten, {})
+        # Sequence or set, but not tuple or list.
+        # (issue44608: there were leaks in the following cases)
+        self.assertRaises(TypeError, _tkinter._flatten, 'string')
+        self.assertRaises(TypeError, _tkinter._flatten, {'set'})
 
 
 class TclTest(unittest.TestCase):
diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
@@ -661,6 +661,39 @@ def test_or_types_operator(self):
             x.__args__ = [str, int]
             (int | str ) == x
 
+    def test_instancecheck(self):
+        x = int | str
+        self.assertIsInstance(1, x)
+        self.assertIsInstance(True, x)
+        self.assertIsInstance('a', x)
+        self.assertNotIsInstance(None, x)
+        self.assertTrue(issubclass(int, x))
+        self.assertTrue(issubclass(bool, x))
+        self.assertTrue(issubclass(str, x))
+        self.assertFalse(issubclass(type(None), x))
+        x = int | None
+        self.assertIsInstance(None, x)
+        self.assertTrue(issubclass(type(None), x))
+        x = int | collections.abc.Mapping
+        self.assertIsInstance({}, x)
+        self.assertTrue(issubclass(dict, x))
+
+    def test_bad_instancecheck(self):
+        class BadMeta(type):
+            def __instancecheck__(cls, inst):
+                1/0
+        x = int | BadMeta('A', (), {})
+        self.assertTrue(isinstance(1, x))
+        self.assertRaises(ZeroDivisionError, isinstance, [], x)
+
+    def test_bad_subclasscheck(self):
+        class BadMeta(type):
+            def __subclasscheck__(cls, sub):
+                1/0
+        x = int | BadMeta('A', (), {})
+        self.assertTrue(issubclass(int, x))
+        self.assertRaises(ZeroDivisionError, issubclass, list, x)
+
     def test_or_type_operator_with_TypeVar(self):
         TV = typing.TypeVar('T')
         assert TV | str == typing.Union[TV, str]
@@ -754,9 +787,9 @@ def __eq__(self, other):
         for type_ in union_ga:
             with self.subTest(f"check isinstance/issubclass is invalid for {type_}"):
                 with self.assertRaises(TypeError):
-                    isinstance(list, type_)
+                    isinstance(1, type_)
                 with self.assertRaises(TypeError):
-                    issubclass(list, type_)
+                    issubclass(int, type_)
 
     def test_or_type_operator_with_bad_module(self):
         class TypeVar:
diff --git a/Mac/README.rst b/Mac/README.rst
@@ -192,7 +192,7 @@ Building and using a framework-based Python on macOS
 
 
 1. Why would I want a framework Python instead of a normal static Python?
---------------------------------------------------------------------------
+-------------------------------------------------------------------------
 
 The main reason is because you want to create GUI programs in Python. With the
 exception of X11/XDarwin-based GUI toolkits all GUI programs need to be run
@@ -206,7 +206,7 @@ only two places: "/Library/Framework/Python.framework" and
 "/Applications/Python <VERSION>" where ``<VERSION>`` can be e.g. "3.8",
 "2.7", etc.  This simplifies matters for users installing
 Python from a binary distribution if they want to get rid of it again. Moreover,
-due to the way frameworks work, usera without admin privileges can install a
+due to the way frameworks work, users without admin privileges can install a
 binary distribution in their home directory without recompilation.
 
 2. How does a framework Python differ from a normal static Python?
@@ -272,7 +272,7 @@ normal frameworkinstall which installs the Tools directory into
 distributions.
 
 What do all these programs do?
-===============================
+==============================
 
 "IDLE.app" is an integrated development environment for Python: editor,
 debugger, etc.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-05-11-12-44-03.bpo-33346.ZgBkvB.rst b/Misc/NEWS.d/next/Core and Builtins/2018-05-11-12-44-03.bpo-33346.ZgBkvB.rst
@@ -0,0 +1,3 @@
+Asynchronous comprehensions are now allowed inside comprehensions in
+asynchronous functions.  Outer comprehensions implicitly become
+asynchronous.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-07-13-20-22-12.bpo-44606.S3Bv2w.rst b/Misc/NEWS.d/next/Core and Builtins/2021-07-13-20-22-12.bpo-44606.S3Bv2w.rst
@@ -0,0 +1 @@
+Fix ``__instancecheck__`` and ``__subclasscheck__`` for the union type.
diff --git a/Misc/NEWS.d/next/Library/2019-11-12-18-59-33.bpo-38741.W7IYkq.rst b/Misc/NEWS.d/next/Library/2019-11-12-18-59-33.bpo-38741.W7IYkq.rst
@@ -0,0 +1 @@
+:mod:`configparser`: using ']' inside a section header will no longer cut the section name short at the ']'
diff --git a/Misc/NEWS.d/next/Library/2021-07-13-09-01-33.bpo-44608.R3IcM1.rst b/Misc/NEWS.d/next/Library/2021-07-13-09-01-33.bpo-44608.R3IcM1.rst
@@ -0,0 +1,2 @@
+Fix memory leak in :func:`_tkinter._flatten` if it is called with a sequence
+or set, but not list or tuple.
diff --git a/Misc/NEWS.d/next/Windows/2021-07-13-15-32-49.bpo-44572.gXvhDc.rst b/Misc/NEWS.d/next/Windows/2021-07-13-15-32-49.bpo-44572.gXvhDc.rst
@@ -0,0 +1 @@
+Avoid consuming standard input in the :mod:`platform` module
diff --git a/Modules/_csv.c b/Modules/_csv.c
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
diff --git a/Objects/unionobject.c b/Objects/unionobject.c
diff --git a/Python/compile.c b/Python/compile.c
diff --git a/Python/symtable.c b/Python/symtable.c
