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author | Guido van Rossum <guido@python.org> | 2007-11-16 00:35:22 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 2007-11-16 00:35:22 (GMT) |
commit | 3d392eb3273aefeca2741aee9f0e31e3b79b1043 (patch) | |
tree | 7766b1aad797ebe0f8ee5316e561b3f37a45d3ea /Doc/library | |
parent | 5b8b1555de033c0f1646bce5fd130567297da019 (diff) | |
download | cpython-3d392eb3273aefeca2741aee9f0e31e3b79b1043.zip cpython-3d392eb3273aefeca2741aee9f0e31e3b79b1043.tar.gz cpython-3d392eb3273aefeca2741aee9f0e31e3b79b1043.tar.bz2 |
Merged revisions 58947-59004 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r58952 | christian.heimes | 2007-11-12 10:58:08 -0800 (Mon, 12 Nov 2007) | 6 lines
readline module cleanup
fixed indention to tabs
use Py_RETURN_NONE macro
added more error checks to on_completion_display_matches_hook
open question: Does PyList_SetItem(l, i, o) steal a reference to o in the case of an error?
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r58956 | guido.van.rossum | 2007-11-12 12:06:40 -0800 (Mon, 12 Nov 2007) | 2 lines
Add the test from issue 1704621 (the issue itself is already fixed here).
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r58963 | amaury.forgeotdarc | 2007-11-13 13:54:28 -0800 (Tue, 13 Nov 2007) | 23 lines
Merge from py3k branch:
Correction for issue1265 (pdb bug with "with" statement).
When an unfinished generator-iterator is garbage collected, PyEval_EvalFrameEx
is called with a GeneratorExit exception set. This leads to funny results
if the sys.settrace function itself makes use of generators.
A visible effect is that the settrace function is reset to None.
Another is that the eventual "finally" block of the generator is not called.
It is necessary to save/restore the exception around the call to the trace
function.
This happens a lot with py3k: isinstance() of an ABCMeta instance runs
def __instancecheck__(cls, instance):
"""Override for isinstance(instance, cls)."""
return any(cls.__subclasscheck__(c)
for c in {instance.__class__, type(instance)})
which lets an opened generator expression each time it returns True.
Backport candidate, even if the case is less frequent in 2.5.
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r58968 | georg.brandl | 2007-11-14 05:59:09 -0800 (Wed, 14 Nov 2007) | 2 lines
Remove dead link from random docs.
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r58971 | raymond.hettinger | 2007-11-14 14:56:16 -0800 (Wed, 14 Nov 2007) | 1 line
Make __fields__ read-only. Suggested by Issac Morland
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r58972 | raymond.hettinger | 2007-11-14 15:02:30 -0800 (Wed, 14 Nov 2007) | 1 line
Add test for __fields__ being read-only
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r58975 | raymond.hettinger | 2007-11-14 18:44:53 -0800 (Wed, 14 Nov 2007) | 6 lines
Accept Issac Morland's suggestion for __replace__ to allow multiple replacements
(suprisingly, this simplifies the signature, improves clarity, and is comparably fast).
Update the docs to reflect a previous change to the function name.
Add an example to the docs showing how to override the default __repr__ method.
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r58976 | raymond.hettinger | 2007-11-14 18:55:42 -0800 (Wed, 14 Nov 2007) | 1 line
Small improvement to the implementation of __replace__().
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r58977 | raymond.hettinger | 2007-11-14 18:58:20 -0800 (Wed, 14 Nov 2007) | 1 line
Fixup example in docs.
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r58978 | raymond.hettinger | 2007-11-14 19:16:09 -0800 (Wed, 14 Nov 2007) | 1 line
Example of multiple replacements.
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r58998 | raymond.hettinger | 2007-11-15 14:39:34 -0800 (Thu, 15 Nov 2007) | 1 line
Add example for use cases requiring default values.
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r59000 | bill.janssen | 2007-11-15 15:03:03 -0800 (Thu, 15 Nov 2007) | 1 line
add the certificate for the Python SVN repository for testing SSL
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r59004 | guido.van.rossum | 2007-11-15 16:24:44 -0800 (Thu, 15 Nov 2007) | 8 lines
A patch from issue 1378 by roudkerk:
Currently on Windows set_error() make use of a large array which maps
socket error numbers to error messages.
This patch removes that array and just lets PyErr_SetExcFromWindowsErr()
generate the message by using the Win32 function FormatMessage().
........
Diffstat (limited to 'Doc/library')
-rw-r--r-- | Doc/library/collections.rst | 48 | ||||
-rw-r--r-- | Doc/library/random.rst | 5 |
2 files changed, 34 insertions, 19 deletions
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst index ba3ce31..0b856fe 100644 --- a/Doc/library/collections.rst +++ b/Doc/library/collections.rst @@ -10,7 +10,7 @@ This module implements high-performance container datatypes. Currently, there are two datatypes, :class:`deque` and :class:`defaultdict`, and -one datatype factory function, :func:`named_tuple`. Python already +one datatype factory function, :func:`namedtuple`. Python already includes built-in containers, :class:`dict`, :class:`list`, :class:`set`, and :class:`tuple`. In addition, the optional :mod:`bsddb` module has a :meth:`bsddb.btopen` method that can be used to create in-memory @@ -383,14 +383,14 @@ Setting the :attr:`default_factory` to :class:`set` makes the .. _named-tuple-factory: -:func:`named_tuple` Factory Function for Tuples with Named Fields +:func:`namedtuple` Factory Function for Tuples with Named Fields ----------------------------------------------------------------- Named tuples assign meaning to each position in a tuple and allow for more readable, self-documenting code. They can be used wherever regular tuples are used, and they add the ability to access fields by name instead of position index. -.. function:: named_tuple(typename, fieldnames, [verbose]) +.. function:: namedtuple(typename, fieldnames, [verbose]) Returns a new tuple subclass named *typename*. The new subclass is used to create tuple-like objects that have fields accessable by attribute lookup as @@ -415,7 +415,7 @@ they add the ability to access fields by name instead of position index. Example:: - >>> Point = named_tuple('Point', 'x y', verbose=True) + >>> Point = namedtuple('Point', 'x y', verbose=True) class Point(tuple): 'Point(x, y)' __slots__ = () @@ -428,8 +428,8 @@ Example:: 'Return a new dict mapping field names to their values' return dict(zip(('x', 'y'), self)) def __replace__(self, field, value): - 'Return a new Point object replacing one field with a new value' - return Point(**dict(zip(('x', 'y'), self) + [(field, value)])) + 'Return a new Point object replacing specified fields with new values' + return Point(**dict(zip(('x', 'y'), self) + kwds.items())) x = property(itemgetter(0)) y = property(itemgetter(1)) @@ -447,7 +447,7 @@ Example:: Named tuples are especially useful for assigning field names to result tuples returned by the :mod:`csv` or :mod:`sqlite3` modules:: - EmployeeRecord = named_tuple('EmployeeRecord', 'name, age, title, department, paygrade') + EmployeeRecord = namedtuple('EmployeeRecord', 'name, age, title, department, paygrade') from itertools import starmap import csv @@ -486,18 +486,18 @@ two additonal methods and a read-only attribute. >>> p.__asdict__() {'x': 11, 'y': 22} -.. method:: somenamedtuple.__replace__(field, value) +.. method:: somenamedtuple.__replace__(kwargs) - Return a new instance of the named tuple replacing the named *field* with a new *value*: + Return a new instance of the named tuple replacing specified fields with new values: :: >>> p = Point(x=11, y=22) - >>> p.__replace__('x', 33) + >>> p.__replace__(x=33) Point(x=33, y=22) - >>> for recordnum, record in inventory: - ... inventory[recordnum] = record.replace('total', record.price * record.quantity) + >>> for partnum, record in inventory.items(): + ... inventory[partnum] = record.__replace__(price=newprices[partnum], updated=time.now()) .. attribute:: somenamedtuple.__fields__ @@ -509,11 +509,31 @@ two additonal methods and a read-only attribute. >>> p.__fields__ # view the field names ('x', 'y') - >>> Color = named_tuple('Color', 'red green blue') - >>> Pixel = named_tuple('Pixel', Point.__fields__ + Color.__fields__) + >>> Color = namedtuple('Color', 'red green blue') + >>> Pixel = namedtuple('Pixel', Point.__fields__ + Color.__fields__) >>> Pixel(11, 22, 128, 255, 0) Pixel(x=11, y=22, red=128, green=255, blue=0)' +Since a named tuple is a regular Python class, it is easy to add or change +functionality. For example, the display format can be changed by overriding +the :meth:`__repr__` method: + +:: + + >>> Point = namedtuple('Point', 'x y') + >>> Point.__repr__ = lambda self: 'Point(%.3f, %.3f)' % self + >>> Point(x=10, y=20) + Point(10.000, 20.000) + +Default values can be implemented by starting with a prototype instance +and customizing it with :meth:`__replace__`: + +:: + + >>> Account = namedtuple('Account', 'owner balance transaction_count') + >>> model_account = Account('<owner name>', 0.0, 0) + >>> johns_account = model_account.__replace__(owner='John') + .. rubric:: Footnotes .. [#] For information on the star-operator see diff --git a/Doc/library/random.rst b/Doc/library/random.rst index f0d5d12..9b02003 100644 --- a/Doc/library/random.rst +++ b/Doc/library/random.rst @@ -282,8 +282,3 @@ Examples of basic usage:: Wichmann, B. A. & Hill, I. D., "Algorithm AS 183: An efficient and portable pseudo-random number generator", Applied Statistics 31 (1982) 188-190. - http://www.npl.co.uk/ssfm/download/abstracts.html#196 - A modern variation of the Wichmann-Hill generator that greatly increases the - period, and passes now-standard statistical tests that the original generator - failed. - |