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author | Georg Brandl <georg@python.org> | 2009-10-27 20:24:45 (GMT) |
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committer | Georg Brandl <georg@python.org> | 2009-10-27 20:24:45 (GMT) |
commit | 628e6f908edcae8e2785600fc1f7f8effa3132d8 (patch) | |
tree | abfa8eaa745c5a4cb33a9114ad8a210e42c025fe /Doc/reference | |
parent | 1e8cbe36cc2455296d38f927d1ab54b93d894881 (diff) | |
download | cpython-628e6f908edcae8e2785600fc1f7f8effa3132d8.zip cpython-628e6f908edcae8e2785600fc1f7f8effa3132d8.tar.gz cpython-628e6f908edcae8e2785600fc1f7f8effa3132d8.tar.bz2 |
Merged revisions 75797 via svnmerge from
svn+ssh://svn.python.org/python/branches/py3k
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r75797 | georg.brandl | 2009-10-27 16:28:25 +0100 (Di, 27 Okt 2009) | 129 lines
Merged revisions 75365,75394,75402-75403,75418,75459,75484,75592-75596,75600,75602-75607,75610-75613,75616-75617,75623,75627,75640,75647,75696,75795 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r75365 | georg.brandl | 2009-10-11 22:16:16 +0200 (So, 11 Okt 2009) | 1 line
Fix broken links found by "make linkcheck". scipy.org seems to be done right now, so I could not verify links going there.
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r75394 | georg.brandl | 2009-10-13 20:10:59 +0200 (Di, 13 Okt 2009) | 1 line
Fix markup.
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r75402 | georg.brandl | 2009-10-14 17:51:48 +0200 (Mi, 14 Okt 2009) | 1 line
#7125: fix typo.
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r75403 | georg.brandl | 2009-10-14 17:57:46 +0200 (Mi, 14 Okt 2009) | 1 line
#7126: os.environ changes *do* take effect in subprocesses started with os.system().
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r75418 | georg.brandl | 2009-10-14 20:48:32 +0200 (Mi, 14 Okt 2009) | 1 line
#7116: str.join() takes an iterable.
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r75459 | georg.brandl | 2009-10-17 10:57:43 +0200 (Sa, 17 Okt 2009) | 1 line
Fix refleaks in _ctypes PyCSimpleType_New, which fixes the refleak seen in test___all__.
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r75484 | georg.brandl | 2009-10-18 09:58:12 +0200 (So, 18 Okt 2009) | 1 line
Fix missing word.
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r75592 | georg.brandl | 2009-10-22 09:05:48 +0200 (Do, 22 Okt 2009) | 1 line
Fix punctuation.
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r75593 | georg.brandl | 2009-10-22 09:06:49 +0200 (Do, 22 Okt 2009) | 1 line
Revert unintended change.
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r75594 | georg.brandl | 2009-10-22 09:56:02 +0200 (Do, 22 Okt 2009) | 1 line
Fix markup.
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r75595 | georg.brandl | 2009-10-22 09:56:56 +0200 (Do, 22 Okt 2009) | 1 line
Fix duplicate target.
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r75596 | georg.brandl | 2009-10-22 10:05:04 +0200 (Do, 22 Okt 2009) | 1 line
Add a new directive marking up implementation details and start using it.
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r75600 | georg.brandl | 2009-10-22 13:01:46 +0200 (Do, 22 Okt 2009) | 1 line
Make it more robust.
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r75602 | georg.brandl | 2009-10-22 13:28:06 +0200 (Do, 22 Okt 2009) | 1 line
Document new directive.
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r75603 | georg.brandl | 2009-10-22 13:28:23 +0200 (Do, 22 Okt 2009) | 1 line
Allow short form with text as argument.
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r75604 | georg.brandl | 2009-10-22 13:36:50 +0200 (Do, 22 Okt 2009) | 1 line
Fix stylesheet for multi-paragraph impl-details.
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r75605 | georg.brandl | 2009-10-22 13:48:10 +0200 (Do, 22 Okt 2009) | 1 line
Use "impl-detail" directive where applicable.
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r75606 | georg.brandl | 2009-10-22 17:00:06 +0200 (Do, 22 Okt 2009) | 1 line
#6324: membership test tries iteration via __iter__.
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r75607 | georg.brandl | 2009-10-22 17:04:09 +0200 (Do, 22 Okt 2009) | 1 line
#7088: document new functions in signal as Unix-only.
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r75610 | georg.brandl | 2009-10-22 17:27:24 +0200 (Do, 22 Okt 2009) | 1 line
Reorder __slots__ fine print and add a clarification.
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r75611 | georg.brandl | 2009-10-22 17:42:32 +0200 (Do, 22 Okt 2009) | 1 line
#7035: improve docs of the various <method>_errors() functions, and give them docstrings.
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r75612 | georg.brandl | 2009-10-22 17:52:15 +0200 (Do, 22 Okt 2009) | 1 line
#7156: document curses as Unix-only.
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r75613 | georg.brandl | 2009-10-22 17:54:35 +0200 (Do, 22 Okt 2009) | 1 line
#6977: getopt does not support optional option arguments.
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r75616 | georg.brandl | 2009-10-22 18:17:05 +0200 (Do, 22 Okt 2009) | 1 line
Add proper references.
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r75617 | georg.brandl | 2009-10-22 18:20:55 +0200 (Do, 22 Okt 2009) | 1 line
Make printout margin important.
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r75623 | georg.brandl | 2009-10-23 10:14:44 +0200 (Fr, 23 Okt 2009) | 1 line
#7188: fix optionxform() docs.
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r75627 | fred.drake | 2009-10-23 15:04:51 +0200 (Fr, 23 Okt 2009) | 2 lines
add further note about what's passed to optionxform
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r75640 | neil.schemenauer | 2009-10-23 21:58:17 +0200 (Fr, 23 Okt 2009) | 2 lines
Improve some docstrings in the 'warnings' module.
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r75647 | georg.brandl | 2009-10-24 12:04:19 +0200 (Sa, 24 Okt 2009) | 1 line
Fix markup.
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r75696 | georg.brandl | 2009-10-25 21:25:43 +0100 (So, 25 Okt 2009) | 1 line
Fix a demo.
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r75795 | georg.brandl | 2009-10-27 16:10:22 +0100 (Di, 27 Okt 2009) | 1 line
Fix a strange mis-edit.
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Diffstat (limited to 'Doc/reference')
-rw-r--r-- | Doc/reference/datamodel.rst | 37 | ||||
-rw-r--r-- | Doc/reference/executionmodel.rst | 2 | ||||
-rw-r--r-- | Doc/reference/expressions.rst | 21 | ||||
-rw-r--r-- | Doc/reference/simple_stmts.rst | 16 |
4 files changed, 47 insertions, 29 deletions
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst index 971c06e..36fc575 100644 --- a/Doc/reference/datamodel.rst +++ b/Doc/reference/datamodel.rst @@ -59,13 +59,16 @@ Objects are never explicitly destroyed; however, when they become unreachable they may be garbage-collected. An implementation is allowed to postpone garbage collection or omit it altogether --- it is a matter of implementation quality how garbage collection is implemented, as long as no objects are collected that -are still reachable. (Implementation note: CPython currently uses a -reference-counting scheme with (optional) delayed detection of cyclically linked -garbage, which collects most objects as soon as they become unreachable, but is -not guaranteed to collect garbage containing circular references. See the -documentation of the :mod:`gc` module for information on controlling the -collection of cyclic garbage. Other implementations act differently and CPython -may change.) +are still reachable. + +.. impl-detail:: + + CPython currently uses a reference-counting scheme with (optional) delayed + detection of cyclically linked garbage, which collects most objects as soon + as they become unreachable, but is not guaranteed to collect garbage + containing circular references. See the documentation of the :mod:`gc` + module for information on controlling the collection of cyclic garbage. + Other implementations act differently and CPython may change. Note that the use of the implementation's tracing or debugging facilities may keep objects alive that would normally be collectable. Also note that catching @@ -1469,15 +1472,15 @@ Notes on using *__slots__* *__slots__*; otherwise, the class attribute would overwrite the descriptor assignment. +* The action of a *__slots__* declaration is limited to the class where it is + defined. As a result, subclasses will have a *__dict__* unless they also define + *__slots__* (which must only contain names of any *additional* slots). + * If a class defines a slot also defined in a base class, the instance variable defined by the base class slot is inaccessible (except by retrieving its descriptor directly from the base class). This renders the meaning of the program undefined. In the future, a check may be added to prevent this. -* The action of a *__slots__* declaration is limited to the class where it is - defined. As a result, subclasses will have a *__dict__* unless they also define - *__slots__*. - * Nonempty *__slots__* does not work for classes derived from "variable-length" built-in types such as :class:`int`, :class:`str` and :class:`tuple`. @@ -1714,12 +1717,16 @@ implemented as an iteration through a sequence. However, container objects can supply the following special method with a more efficient implementation, which also does not require the object be a sequence. - .. method:: object.__contains__(self, item) - Called to implement membership test operators. Should return true if *item* is - in *self*, false otherwise. For mapping objects, this should consider the keys - of the mapping rather than the values or the key-item pairs. + Called to implement membership test operators. Should return true if *item* + is in *self*, false otherwise. For mapping objects, this should consider the + keys of the mapping rather than the values or the key-item pairs. + + For objects that don't define :meth:`__contains__`, the membership test first + tries iteration via :meth:`__iter__`, then the old sequence iteration + protocol via :meth:`__getitem__`, see :ref:`this section in the language + reference <membership-test-details>`. .. _numeric-types: diff --git a/Doc/reference/executionmodel.rst b/Doc/reference/executionmodel.rst index 68ee654..90791d2 100644 --- a/Doc/reference/executionmodel.rst +++ b/Doc/reference/executionmodel.rst @@ -129,7 +129,7 @@ the built-in module :mod:`builtins`; when in any other module, itself. ``__builtins__`` can be set to a user-created dictionary to create a weak form of restricted execution. -.. note:: +.. impl-detail:: Users should not touch ``__builtins__``; it is strictly an implementation detail. Users wanting to override values in the built-in namespace should diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index cdb802a..d074ebb 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -639,13 +639,13 @@ slots for which no default value is specified, a :exc:`TypeError` exception is raised. Otherwise, the list of filled slots is used as the argument list for the call. -.. note:: +.. impl-detail:: - An implementation may provide built-in functions whose positional parameters do - not have names, even if they are 'named' for the purpose of documentation, and - which therefore cannot be supplied by keyword. In CPython, this is the case for - functions implemented in C that use :cfunc:`PyArg_ParseTuple` to parse their - arguments. + An implementation may provide built-in functions whose positional parameters + do not have names, even if they are 'named' for the purpose of documentation, + and which therefore cannot be supplied by keyword. In CPython, this is the + case for functions implemented in C that use :cfunc:`PyArg_ParseTuple` to + parse their arguments. If there are more positional arguments than there are formal parameter slots, a :exc:`TypeError` exception is raised, unless a formal parameter using the syntax @@ -1053,6 +1053,8 @@ cross-type comparison is not supported, the comparison method returns supported cross-type comparisons and unsupported comparisons. For example, ``Decimal(2) == 2`` and `2 == float(2)`` but ``Decimal(2) != float(2)``. +.. _membership-test-details: + The operators :keyword:`in` and :keyword:`not in` test for membership. ``x in s`` evaluates to true if *x* is a member of *s*, and false otherwise. ``x not in s`` returns the negation of ``x in s``. All built-in sequences and set types @@ -1069,7 +1071,12 @@ return ``True``. For user-defined classes which define the :meth:`__contains__` method, ``x in y`` is true if and only if ``y.__contains__(x)`` is true. -For user-defined classes which do not define :meth:`__contains__` and do define +For user-defined classes which do not define :meth:`__contains__` but do define +:meth:`__iter__`, ``x in y`` is true if some value ``z`` with ``x == z`` is +produced while iterating over ``y``. If an exception is raised during the +iteration, it is as if :keyword:`in` raised that exception. + +Lastly, the old-style iteration protocol is tried: if a class defines :meth:`__getitem__`, ``x in y`` is true if and only if there is a non-negative integer index *i* such that ``x == y[i]``, and all lower integer indices do not raise :exc:`IndexError` exception. (If any other exception is raised, it is as diff --git a/Doc/reference/simple_stmts.rst b/Doc/reference/simple_stmts.rst index 8c95623..b3fc891 100644 --- a/Doc/reference/simple_stmts.rst +++ b/Doc/reference/simple_stmts.rst @@ -236,9 +236,11 @@ Assignment of an object to a single target is recursively defined as follows. from the length of the assigned sequence, thus changing the length of the target sequence, if the object allows it. -(In the current implementation, the syntax for targets is taken to be the same -as for expressions, and invalid syntax is rejected during the code generation -phase, causing less detailed error messages.) +.. impl-detail:: + + In the current implementation, the syntax for targets is taken to be the same + as for expressions, and invalid syntax is rejected during the code generation + phase, causing less detailed error messages. WARNING: Although the definition of assignment implies that overlaps between the left-hand side and the right-hand side are 'safe' (for example ``a, b = b, a`` @@ -935,9 +937,11 @@ Names listed in a :keyword:`global` statement must not be defined as formal parameters or in a :keyword:`for` loop control target, :keyword:`class` definition, function definition, or :keyword:`import` statement. -(The current implementation does not enforce the latter two restrictions, but -programs should not abuse this freedom, as future implementations may enforce -them or silently change the meaning of the program.) +.. impl-detail:: + + The current implementation does not enforce the latter two restrictions, but + programs should not abuse this freedom, as future implementations may enforce + them or silently change the meaning of the program. .. index:: builtin: exec |