cpython/Doc/library/plistlib.rst

248 lines
7.4 KiB
ReStructuredText

:mod:`plistlib` --- Generate and parse Mac OS X ``.plist`` files
================================================================
.. module:: plistlib
:synopsis: Generate and parse Mac OS X plist files.
.. moduleauthor:: Jack Jansen
.. sectionauthor:: Georg Brandl <georg@python.org>
.. (harvested from docstrings in the original file)
.. index::
pair: plist; file
single: property list
**Source code:** :source:`Lib/plistlib.py`
--------------
This module provides an interface for reading and writing the "property list"
files used mainly by Mac OS X and supports both binary and XML plist files.
The property list (``.plist``) file format is a simple serialization supporting
basic object types, like dictionaries, lists, numbers and strings. Usually the
top level object is a dictionary.
To write out and to parse a plist file, use the :func:`dump` and
:func:`load` functions.
To work with plist data in bytes objects, use :func:`dumps`
and :func:`loads`.
Values can be strings, integers, floats, booleans, tuples, lists, dictionaries
(but only with string keys), :class:`Data`, :class:`bytes`, :class:`bytesarray`
or :class:`datetime.datetime` objects.
.. seealso::
`PList manual page <http://developer.apple.com/documentation/Darwin/Reference/ManPages/man5/plist.5.html>`_
Apple's documentation of the file format.
This module defines the following functions:
.. function:: load(fp, \*, fmt=None, use_builtin_types=True, dict_type=dict)
Read a plist file. *fp* should be a readable and binary file object.
Return the unpacked root object (which usually is a
dictionary).
The *fmt* is the format of the file and the following values are valid:
* :data:`None`: Autodetect the file format
* :data:`FMT_XML`: XML file format
* :data:`FMT_BINARY`: Binary plist format
If *use_builtin_types* is true (the default) binary data will be returned
as instances of :class:`bytes`, otherwise it is returned as instances of
:class:`Data`.
The *dict_type* is the type used for dictionaries that are read from the
plist file. The exact structure of the plist can be recovered by using
:class:`collections.OrderedDict` (although the order of keys shouldn't be
important in plist files).
XML data for the :data:`FMT_XML` format is parsed using the Expat parser
from :mod:`xml.parsers.expat` -- see its documentation for possible
exceptions on ill-formed XML. Unknown elements will simply be ignored
by the plist parser.
The parser for the binary format raises :exc:`InvalidFileException`
when the file cannot be parsed.
.. versionadded:: 3.4
.. function:: loads(data, \*, fmt=None, use_builtin_types=True, dict_type=dict)
Load a plist from a bytes object. See :func:`load` for an explanation of
the keyword arguments.
.. versionadded:: 3.4
.. function:: dump(value, fp, \*, fmt=FMT_XML, sort_keys=True, skipkeys=False)
Write *value* to a plist file. *Fp* should be a writable, binary
file object.
The *fmt* argument specifies the format of the plist file and can be
one of the following values:
* :data:`FMT_XML`: XML formatted plist file
* :data:`FMT_BINARY`: Binary formatted plist file
When *sort_keys* is true (the default) the keys for dictionaries will be
written to the plist in sorted order, otherwise they will be written in
the iteration order of the dictionary.
When *skipkeys* is false (the default) the function raises :exc:`TypeError`
when a key of a dictionary is not a string, otherwise such keys are skipped.
A :exc:`TypeError` will be raised if the object is of an unsupported type or
a container that contains objects of unsupported types.
An :exc:`OverflowError` will be raised for integer values that cannot
be represented in (binary) plist files.
.. warning::
For compatibility with Apple's libraries it is possible to write
an integer in the range from 2 ** 63 upto (and including) 2 ** 64
to binary plists, even though these will be read back as negative
values.
.. versionadded: 3.4
.. function:: dumps(value, \*, fmt=FMT_XML, sort_keys=True, skipkeys=False)
Return *value* as a plist-formatted bytes object. See
the documentation for :func:`dump` for an explanation of the keyword
arguments of this function.
.. versionadded: 3.4
The following functions are deprecated:
.. function:: readPlist(pathOrFile)
Read a plist file. *pathOrFile* may be either a file name or a (readable
and binary) file object. Returns the unpacked root object (which usually
is a dictionary).
This function calls :func:`load` to do the actual work, the the documentation
of :func:`that function <load>` for an explanation of the keyword arguments.
.. note::
Dict values in the result have a ``__getattr__`` method that defers
to ``__getitem_``. This means that you can use attribute access to
access items of these dictionaries.
.. deprecated: 3.4 Use :func:`load` instead.
.. function:: writePlist(rootObject, pathOrFile)
Write *rootObject* to an XML plist file. *pathOrFile* may be either a file name
or a (writable and binary) file object
.. deprecated: 3.4 Use :func:`dump` instead.
.. function:: readPlistFromBytes(data)
Read a plist data from a bytes object. Return the root object.
See :func:`load` for a description of the keyword arguments.
.. note::
Dict values in the result have a ``__getattr__`` method that defers
to ``__getitem_``. This means that you can use attribute access to
access items of these dictionaries.
.. deprecated:: 3.4 Use :func:`loads` instead.
.. function:: writePlistToBytes(rootObject)
Return *rootObject* as an XML plist-formatted bytes object.
.. deprecated:: 3.4 Use :func:`dumps` instead.
The following classes are available:
.. class:: Dict([dict]):
Return an extended mapping object with the same value as dictionary
*dict*.
This class is a subclass of :class:`dict` where attribute access can
be used to access items. That is, ``aDict.key`` is the same as
``aDict['key']`` for getting, setting and deleting items in the mapping.
.. deprecated:: 3.0
.. class:: Data(data)
Return a "data" wrapper object around the bytes object *data*. This is used
in functions converting from/to plists to represent the ``<data>`` type
available in plists.
It has one attribute, :attr:`data`, that can be used to retrieve the Python
bytes object stored in it.
.. deprecated:: 3.4 Use a :class:`bytes` object instead
The following constants are avaiable:
.. data:: FMT_XML
The XML format for plist files.
.. versionadded:: 3.4
.. data:: FMT_BINARY
The binary format for plist files
.. versionadded:: 3.4
Examples
--------
Generating a plist::
pl = dict(
aString = "Doodah",
aList = ["A", "B", 12, 32.1, [1, 2, 3]],
aFloat = 0.1,
anInt = 728,
aDict = dict(
anotherString = "<hello & hi there!>",
aThirdString = "M\xe4ssig, Ma\xdf",
aTrueValue = True,
aFalseValue = False,
),
someData = b"<binary gunk>",
someMoreData = b"<lots of binary gunk>" * 10,
aDate = datetime.datetime.fromtimestamp(time.mktime(time.gmtime())),
)
with open(fileName, 'wb') as fp:
dump(pl, fp)
Parsing a plist::
with open(fileName, 'rb') as fp:
pl = load(fp)
print(pl["aKey"])