14.5. "plistlib" --- Generate and parse Mac OS X ".plist" files
***************************************************************

**Source code:** 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 "dump()" and "load()"
functions.

To work with plist data in bytes objects, use "dumps()" and "loads()".

Values can be strings, integers, floats, booleans, tuples, lists,
dictionaries (but only with string keys), "Data", "bytes",
"bytesarray" or "datetime.datetime" objects.

在 3.4 版更改: New API, old API deprecated.  Support for binary format
plists added.

参见:

  PList manual page
     Apple's documentation of the file format.

这个模块定义了以下函数：

plistlib.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:

   * "None": Autodetect the file format

   * "FMT_XML": XML file format

   * "FMT_BINARY": Binary plist format

   If *use_builtin_types* is true (the default) binary data will be
   returned as instances of "bytes", otherwise it is returned as
   instances of "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 "collections.OrderedDict" (although the order of
   keys shouldn't be important in plist files).

   XML data for the "FMT_XML" format is parsed using the Expat parser
   from "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 "InvalidFileException" when
   the file cannot be parsed.

   3.4 新版功能.

plistlib.loads(data, *, fmt=None, use_builtin_types=True, dict_type=dict)

   Load a plist from a bytes object. See "load()" for an explanation
   of the keyword arguments.

   3.4 新版功能.

plistlib.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:

   * "FMT_XML": XML formatted plist file

   * "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
   "TypeError" when a key of a dictionary is not a string, otherwise
   such keys are skipped.

   A "TypeError" will be raised if the object is of an unsupported
   type or a container that contains objects of unsupported types.

   An "OverflowError" will be raised for integer values that cannot be
   represented in (binary) plist files.

   3.4 新版功能.

plistlib.dumps(value, *, fmt=FMT_XML, sort_keys=True, skipkeys=False)

   Return *value* as a plist-formatted bytes object. See the
   documentation for "dump()" for an explanation of the keyword
   arguments of this function.

   3.4 新版功能.

The following functions are deprecated:

plistlib.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 "load()" to do the actual work, see the
   documentation of "that function" for an explanation of the keyword
   arguments.

   注解: 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.

   3.4 版后已移除: Use "load()" instead.

plistlib.writePlist(rootObject, pathOrFile)

   Write *rootObject* to an XML plist file. *pathOrFile* may be either
   a file name or a (writable and binary) file object

   3.4 版后已移除: Use "dump()" instead.

plistlib.readPlistFromBytes(data)

   Read a plist data from a bytes object.  Return the root object.

   See "load()" for a description of the keyword arguments.

   注解: 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.

   3.4 版后已移除: Use "loads()" instead.

plistlib.writePlistToBytes(rootObject)

   Return *rootObject* as an XML plist-formatted bytes object.

   3.4 版后已移除: Use "dumps()" instead.

The following classes are available:

Dict([dict]):

   Return an extended mapping object with the same value as dictionary
   *dict*.

   This class is a subclass of "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.

   3.0 版后已移除.

class plistlib.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, "data", that can be used to retrieve the
   Python bytes object stored in it.

   3.4 版后已移除: Use a "bytes" object instead.

The following constants are available:

plistlib.FMT_XML

   The XML format for plist files.

   3.4 新版功能.

plistlib.FMT_BINARY

   The binary format for plist files

   3.4 新版功能.


14.5.1. 示例
============

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"])
