diff options
| -rw-r--r-- | Doc/whatsnew/3.2.rst | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst index 420173a..e4104d3 100644 --- a/Doc/whatsnew/3.2.rst +++ b/Doc/whatsnew/3.2.rst @@ -260,8 +260,8 @@ when currently pending futures are done executing. A simple of example of :class:`~concurrent.futures.ThreadPoolExecutor` is a launch of four parallel threads for copying files:: - import shutil - with ThreadPoolExecutor(max_workers=4) as e: + import threading, shutil + with threading.ThreadPoolExecutor(max_workers=4) as e: e.submit(shutil.copy, 'src1.txt', 'dest1.txt') e.submit(shutil.copy, 'src2.txt', 'dest2.txt') e.submit(shutil.copy, 'src3.txt', 'dest3.txt') @@ -712,6 +712,7 @@ functools For example, adding a caching decorator to a database query function can save database accesses for popular searches: + >>> import functools >>> @functools.lru_cache(maxsize=300) >>> def get_phone_number(name): c = conn.cursor() @@ -928,13 +929,15 @@ datetime and time * The :mod:`datetime` module has a new type :class:`~datetime.timezone` that implements the :class:`~datetime.tzinfo` interface by returning a fixed UTC offset and timezone name. This makes it easier to create timezone-aware - datetime objects: + datetime objects:: - >>> datetime.now(timezone.utc) - datetime.datetime(2010, 12, 8, 21, 4, 2, 923754, tzinfo=datetime.timezone.utc) + >>> import datetime - >>> datetime.strptime("01/01/2000 12:00 +0000", "%m/%d/%Y %H:%M %z") - datetime.datetime(2000, 1, 1, 12, 0, tzinfo=datetime.timezone.utc) + >>> datetime.now(timezone.utc) + datetime.datetime(2010, 12, 8, 21, 4, 2, 923754, tzinfo=datetime.timezone.utc) + + >>> datetime.strptime("01/01/2000 12:00 +0000", "%m/%d/%Y %H:%M %z") + datetime.datetime(2000, 1, 1, 12, 0, tzinfo=datetime.timezone.utc) * Also, :class:`~datetime.timedelta` objects can now be multiplied by :class:`float` and divided by :class:`float` and :class:`int` objects. @@ -953,6 +956,7 @@ datetime and time :attr:`time.accept2dyear` be set to *False* so that large date ranges can be used without guesswork: + >>> import time, warnings >>> warnings.resetwarnings() # remove the default warning filters >>> time.accept2dyear = True # guess whether 11 means 11 or 2011 >>> time.asctime((11, 1, 1, 12, 34, 56, 4, 1, 0)) @@ -1044,13 +1048,13 @@ provides functionality similar to :func:`memoryview`. It creates an editable view of the data without making a copy. The buffer's random access and support for slice notation are well-suited to in-place editing:: - import io + >>> REC_LEN, LOC_START, LOC_LEN = 34, 7, 11 - REC_LEN, LOC_START, LOC_LEN = 34, 7, 11 + >>> def change_location(buffer, record_number, location): + start = record_number * REC_LEN + LOC_START + buffer[start: start+LOC_LEN] = location - def change_location(buffer, record_number, location): - start = record_number * REC_LEN + LOC_START - buffer[start: start+LOC_LEN] = location + >>> import io >>> byte_stream = io.BytesIO( b'G3805 storeroom Main chassis ' @@ -1138,8 +1142,11 @@ writing both a function decorator and a context manager for the task, the :func:`~contextlib.contextmanager` provides both capabilities in a single definition:: + from contextlib import contextmanager import logging + logging.basicConfig(level=logging.INFO) + @contextmanager def track_entry_and_exit(name): logging.info('Entering: {}'.format(name)) @@ -1338,6 +1345,7 @@ the builtin :func:`eval` function which is easily abused. Python 3.2 adds strings, bytes, numbers, tuples, lists, dicts, sets, booleans, and None. :: + >>> from ast import literal_request >>> request = "{'req': 3, 'func': 'pow', 'args': (2, 0.5)}" >>> literal_eval(request) @@ -1534,6 +1542,9 @@ the new :mod:`imaplib.IMAP4.starttls` method. (Contributed by Lorenzo M. Catucci and Antoine Pitrou, :issue:`4471`.) .. XXX sys._xoptions http://bugs.python.org/issue10089 +.. XXX perhaps add issue numbers back to datetime +.. XXX more research on attributions +.. XXX tarfile unittest -------- @@ -1735,7 +1746,7 @@ object information for the supplied function, method, source code string or code object. The former returns a string and the latter prints it:: >>> import dis, random - >>> show_code(random.choice) + >>> dis.show_code(random.choice) Name: choice Filename: /Library/Frameworks/Python.framework/Versions/3.2/lib/python3.2/random.py Argument count: 2 @@ -1787,6 +1798,7 @@ details of a given Python installation. :: + >>> import site >>> site.getsitepackages() ['/Library/Frameworks/Python.framework/Versions/3.2/lib/python3.2/site-packages', '/Library/Frameworks/Python.framework/Versions/3.2/lib/site-python', |