cpython/Doc/library/plistlib.rst

: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)

**Source code:** :source:`Lib/plistlib.py`

.. index::
   pair: plist; file
   single: property list

--------------

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.

.. versionchanged:: 3.4
   New API, old API deprecated.  Support for binary format plists added.

.. versionchanged:: 3.8
   Support added for reading and writing :class:`UID` tokens in binary plists as used
   by NSKeyedArchiver and NSKeyedUnarchiver.

.. seealso::

   `PList manual page <https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/PropertyLists/>`_
      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.

   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.

   .. 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, see the documentation
   of :func:`that function <load>` for an explanation of the keyword arguments.

   .. deprecated:: 3.4 Use :func:`load` instead.

   .. versionchanged:: 3.7
      Dict values in the result are now normal dicts.  You no longer can use
      attribute access to access items of these dictionaries.


.. 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.

   .. deprecated:: 3.4 Use :func:`loads` instead.

   .. versionchanged:: 3.7
      Dict values in the result are now normal dicts.  You no longer can use
      attribute access to access items of these dictionaries.


.. 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:: 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.

.. class:: UID(data)

   Wraps an :class:`int`.  This is used when reading or writing NSKeyedArchiver
   encoded data, which contains UID (see PList manual).

   It has one attribute, :attr:`data` which can be used to retrieve the int value
   of the UID.  :attr:`data` must be in the range `0 <= data <= 2**64`.

   .. versionadded:: 3.8


The following constants are available:

.. 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"])