Add a few imports to examples.

This commit is contained in:
Raymond Hettinger 2011-01-26 01:13:26 +00:00
parent 3a7ee3ab5a
commit 14eb4c356e
1 changed files with 25 additions and 13 deletions

View File

@ -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',