diff options
Diffstat (limited to 'Doc/whatsnew/3.5.rst')
| -rw-r--r-- | Doc/whatsnew/3.5.rst | 62 |
1 files changed, 33 insertions, 29 deletions
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst index bf2940c..7b353c1 100644 --- a/Doc/whatsnew/3.5.rst +++ b/Doc/whatsnew/3.5.rst @@ -111,7 +111,7 @@ CPython implementation improvements: Significantly Improved Library Modules: * :class:`collections.OrderedDict` is now implemented in C, which makes it - 4 to 100 times faster. Contributed by Eric Snow in :issue:`16991`. + 4 to 100 times faster. (Contributed by Eric Snow in :issue:`16991`.) * You may now pass bytes to the :mod:`tempfile` module's APIs and it will return the temporary pathname as :class:`bytes` instead of :class:`str`. @@ -213,34 +213,33 @@ An example of a simple HTTP client written using the new syntax:: Similarly to asynchronous iteration, there is a new syntax for asynchronous -context managers:: - - >>> import asyncio - >>> async def coro1(lock): - ... print('coro1: waiting for lock') - ... async with lock: - ... print('coro1: holding the lock') - ... await asyncio.sleep(1) - ... print('coro1: releasing the lock') - ... - >>> async def coro2(lock): - ... print('coro2: waiting for lock') - ... async with lock: - ... print('coro2: holding the lock') - ... await asyncio.sleep(1) - ... print('coro2: releasing the lock') - ... - >>> loop = asyncio.get_event_loop() - >>> lock = asyncio.Lock() - >>> coros = asyncio.gather(coro1(lock), coro2(lock), loop=loop) - >>> loop.run_until_complete(coros) - coro1: waiting for lock - coro1: holding the lock - coro2: waiting for lock - coro1: releasing the lock - coro2: holding the lock - coro2: releasing the lock - >>> loop.close() +context managers. The following script:: + + import asyncio + + async def coro(name, lock): + print('coro {}: waiting for lock'.format(name)) + async with lock: + print('coro {}: holding the lock'.format(name)) + await asyncio.sleep(1) + print('coro {}: releasing the lock'.format(name)) + + loop = asyncio.get_event_loop() + lock = asyncio.Lock() + coros = asyncio.gather(coro(1, lock), coro(2, lock)) + try: + loop.run_until_complete(coros) + finally: + loop.close() + +will print:: + + coro 2: waiting for lock + coro 2: holding the lock + coro 1: waiting for lock + coro 2: releasing the lock + coro 1: holding the lock + coro 1: releasing the lock Note that both :keyword:`async for` and :keyword:`async with` can only be used inside a coroutine function declared with :keyword:`async def`. @@ -325,10 +324,13 @@ unpackings:: >>> *range(4), 4 (0, 1, 2, 3, 4) + >>> [*range(4), 4] [0, 1, 2, 3, 4] + >>> {*range(4), 4, *(5, 6, 7)} {0, 1, 2, 3, 4, 5, 6, 7} + >>> {'x': 1, **{'y': 2}} {'x': 1, 'y': 2} @@ -352,6 +354,7 @@ Examples:: >>> b'Hello %s!' % b'World' b'Hello World!' + >>> b'x=%i y=%f' % (1, 2.5) b'x=1 y=2.500000' @@ -362,6 +365,7 @@ Unicode is not allowed for ``%s``, but it is accepted by ``%a`` (equivalent of Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: %b requires bytes, or an object that implements __bytes__, not 'str' + >>> b'price: %a' % '10€' b"price: '10\\u20ac'" |