Lib/fontTools/misc/plistlib/__init__.py - third_party/fonttools - Git at Google

 import collections.abc
 import re
 from typing import (
     Any,
     Callable,
     Dict,
     List,
     Mapping,
     MutableMapping,
     Optional,
     Sequence,
     Type,
     Union,
     IO,
 )
 import warnings
 from io import BytesIO
 from datetime import datetime
 from base64 import b64encode, b64decode
 from numbers import Integral
 from types import SimpleNamespace
 from functools import singledispatch

 from fontTools.misc import etree

 from fontTools.misc.py23 import tostr


 # By default, we
 #  - deserialize <data> elements as bytes and
 #  - serialize bytes as <data> elements.
 # Before, on Python 2, we
 #  - deserialized <data> elements as plistlib.Data objects, in order to
 #    distinguish them from the built-in str type (which is bytes on python2)
 #  - serialized bytes as <string> elements (they must have only contained
 #    ASCII characters in this case)
 # You can pass use_builtin_types=[True|False] to the load/dump etc. functions
 # to enforce a specific treatment.
 # NOTE that unicode type always maps to <string> element, and plistlib.Data
 # always maps to <data> element, regardless of use_builtin_types.
 USE_BUILTIN_TYPES = True

 XML_DECLARATION = b"""<?xml version='1.0' encoding='UTF-8'?>"""

 PLIST_DOCTYPE = (
     b'<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" '
     b'"http://www.apple.com/DTDs/PropertyList-1.0.dtd">'
 )


 # Date should conform to a subset of ISO 8601:
 # YYYY '-' MM '-' DD 'T' HH ':' MM ':' SS 'Z'
 _date_parser = re.compile(
     r"(?P<year>\d\d\d\d)"
     r"(?:-(?P<month>\d\d)"
     r"(?:-(?P<day>\d\d)"
     r"(?:T(?P<hour>\d\d)"
     r"(?::(?P<minute>\d\d)"
     r"(?::(?P<second>\d\d))"
     r"?)?)?)?)?Z",
     re.ASCII,
 )


 def _date_from_string(s: str) -> datetime:
     order = ("year", "month", "day", "hour", "minute", "second")
     m = _date_parser.match(s)
     if m is None:
         raise ValueError(f"Expected ISO 8601 date string, but got '{s:r}'.")
     gd = m.groupdict()
     lst = []
     for key in order:
         val = gd[key]
         if val is None:
             break
         lst.append(int(val))
     # NOTE: mypy doesn't know that lst is 6 elements long.
     return datetime(*lst)  # type:ignore


 def _date_to_string(d: datetime) -> str:
     return "%04d-%02d-%02dT%02d:%02d:%02dZ" % (
         d.year,
         d.month,
         d.day,
         d.hour,
         d.minute,
         d.second,
     )


 class Data:
     """Represents binary data when ``use_builtin_types=False.``

     This class wraps binary data loaded from a plist file when the
     ``use_builtin_types`` argument to the loading function (:py:func:`fromtree`,
     :py:func:`load`, :py:func:`loads`) is false.

     The actual binary data is retrieved using the ``data`` attribute.
     """

     def __init__(self, data: bytes) -> None:
         if not isinstance(data, bytes):
             raise TypeError("Expected bytes, found %s" % type(data).__name__)
         self.data = data

     @classmethod
     def fromBase64(cls, data: Union[bytes, str]) -> "Data":
         return cls(b64decode(data))

     def asBase64(self, maxlinelength: int = 76, indent_level: int = 1) -> bytes:
         return _encode_base64(
             self.data, maxlinelength=maxlinelength, indent_level=indent_level
         )

     def __eq__(self, other: Any) -> bool:
         if isinstance(other, self.__class__):
             return self.data == other.data
         elif isinstance(other, bytes):
             return self.data == other
         else:
             return NotImplemented

     def __repr__(self) -> str:
         return "%s(%s)" % (self.__class__.__name__, repr(self.data))


 def _encode_base64(
     data: bytes, maxlinelength: Optional[int] = 76, indent_level: int = 1
 ) -> bytes:
     data = b64encode(data)
     if data and maxlinelength:
         # split into multiple lines right-justified to 'maxlinelength' chars
         indent = b"\n" + b"  " * indent_level
         max_length = max(16, maxlinelength - len(indent))
         chunks = []
         for i in range(0, len(data), max_length):
             chunks.append(indent)
             chunks.append(data[i : i + max_length])
         chunks.append(indent)
         data = b"".join(chunks)
     return data


 # Mypy does not support recursive type aliases as of 0.782, Pylance does.
 # https://github.com/python/mypy/issues/731
 # https://devblogs.microsoft.com/python/pylance-introduces-five-new-features-that-enable-type-magic-for-python-developers/#1-support-for-recursive-type-aliases
 PlistEncodable = Union[
     bool,
     bytes,
     Data,
     datetime,
     float,
     int,
     Mapping[str, Any],
     Sequence[Any],
     str,
 ]


 class PlistTarget:
     """Event handler using the ElementTree Target API that can be
     passed to a XMLParser to produce property list objects from XML.
     It is based on the CPython plistlib module's _PlistParser class,
     but does not use the expat parser.

     >>> from fontTools.misc import etree
     >>> parser = etree.XMLParser(target=PlistTarget())
     >>> result = etree.XML(
     ...     "<dict>"
     ...     "    <key>something</key>"
     ...     "    <string>blah</string>"
     ...     "</dict>",
     ...     parser=parser)
     >>> result == {"something": "blah"}
     True

     Links:
     https://github.com/python/cpython/blob/master/Lib/plistlib.py
     http://lxml.de/parsing.html#the-target-parser-interface
     """

     def __init__(
         self,
         use_builtin_types: Optional[bool] = None,
         dict_type: Type[MutableMapping[str, Any]] = dict,
     ) -> None:
         self.stack: List[PlistEncodable] = []
         self.current_key: Optional[str] = None
         self.root: Optional[PlistEncodable] = None
         if use_builtin_types is None:
             self._use_builtin_types = USE_BUILTIN_TYPES
         else:
             if use_builtin_types is False:
                 warnings.warn(
                     "Setting use_builtin_types to False is deprecated and will be "
                     "removed soon.",
                     DeprecationWarning,
                 )
             self._use_builtin_types = use_builtin_types
         self._dict_type = dict_type

     def start(self, tag: str, attrib: Mapping[str, str]) -> None:
         self._data: List[str] = []
         handler = _TARGET_START_HANDLERS.get(tag)
         if handler is not None:
             handler(self)

     def end(self, tag: str) -> None:
         handler = _TARGET_END_HANDLERS.get(tag)
         if handler is not None:
             handler(self)

     def data(self, data: str) -> None:
         self._data.append(data)

     def close(self) -> PlistEncodable:
         if self.root is None:
             raise ValueError("No root set.")
         return self.root

     # helpers

     def add_object(self, value: PlistEncodable) -> None:
         if self.current_key is not None:
             stack_top = self.stack[-1]
             if not isinstance(stack_top, collections.abc.MutableMapping):
                 raise ValueError("unexpected element: %r" % stack_top)
             stack_top[self.current_key] = value
             self.current_key = None
         elif not self.stack:
             # this is the root object
             self.root = value
         else:
             stack_top = self.stack[-1]
             if not isinstance(stack_top, list):
                 raise ValueError("unexpected element: %r" % stack_top)
             stack_top.append(value)

     def get_data(self) -> str:
         data = "".join(self._data)
         self._data = []
         return data


 # event handlers


 def start_dict(self: PlistTarget) -> None:
     d = self._dict_type()
     self.add_object(d)
     self.stack.append(d)


 def end_dict(self: PlistTarget) -> None:
     if self.current_key:
         raise ValueError("missing value for key '%s'" % self.current_key)
     self.stack.pop()


 def end_key(self: PlistTarget) -> None:
     if self.current_key or not isinstance(self.stack[-1], collections.abc.Mapping):
         raise ValueError("unexpected key")
     self.current_key = self.get_data()


 def start_array(self: PlistTarget) -> None:
     a: List[PlistEncodable] = []
     self.add_object(a)
     self.stack.append(a)


 def end_array(self: PlistTarget) -> None:
     self.stack.pop()


 def end_true(self: PlistTarget) -> None:
     self.add_object(True)


 def end_false(self: PlistTarget) -> None:
     self.add_object(False)


 def end_integer(self: PlistTarget) -> None:
     self.add_object(int(self.get_data()))


 def end_real(self: PlistTarget) -> None:
     self.add_object(float(self.get_data()))


 def end_string(self: PlistTarget) -> None:
     self.add_object(self.get_data())


 def end_data(self: PlistTarget) -> None:
     if self._use_builtin_types:
         self.add_object(b64decode(self.get_data()))
     else:
         self.add_object(Data.fromBase64(self.get_data()))


 def end_date(self: PlistTarget) -> None:
     self.add_object(_date_from_string(self.get_data()))


 _TARGET_START_HANDLERS: Dict[str, Callable[[PlistTarget], None]] = {
     "dict": start_dict,
     "array": start_array,
 }

 _TARGET_END_HANDLERS: Dict[str, Callable[[PlistTarget], None]] = {
     "dict": end_dict,
     "array": end_array,
     "key": end_key,
     "true": end_true,
     "false": end_false,
     "integer": end_integer,
     "real": end_real,
     "string": end_string,
     "data": end_data,
     "date": end_date,
 }


 # functions to build element tree from plist data


 def _string_element(value: str, ctx: SimpleNamespace) -> etree.Element:
     el = etree.Element("string")
     el.text = value
     return el


 def _bool_element(value: bool, ctx: SimpleNamespace) -> etree.Element:
     if value:
         return etree.Element("true")
     return etree.Element("false")


 def _integer_element(value: int, ctx: SimpleNamespace) -> etree.Element:
     if -1 << 63 <= value < 1 << 64:
         el = etree.Element("integer")
         el.text = "%d" % value
         return el
     raise OverflowError(value)


 def _real_element(value: float, ctx: SimpleNamespace) -> etree.Element:
     el = etree.Element("real")
     el.text = repr(value)
     return el


 def _dict_element(d: Mapping[str, PlistEncodable], ctx: SimpleNamespace) -> etree.Element:
     el = etree.Element("dict")
     items = d.items()
     if ctx.sort_keys:
         items = sorted(items)  # type: ignore
     ctx.indent_level += 1
     for key, value in items:
         if not isinstance(key, str):
             if ctx.skipkeys:
                 continue
             raise TypeError("keys must be strings")
         k = etree.SubElement(el, "key")
         k.text = tostr(key, "utf-8")
         el.append(_make_element(value, ctx))
     ctx.indent_level -= 1
     return el


 def _array_element(array: Sequence[PlistEncodable], ctx: SimpleNamespace) -> etree.Element:
     el = etree.Element("array")
     if len(array) == 0:
         return el
     ctx.indent_level += 1
     for value in array:
         el.append(_make_element(value, ctx))
     ctx.indent_level -= 1
     return el


 def _date_element(date: datetime, ctx: SimpleNamespace) -> etree.Element:
     el = etree.Element("date")
     el.text = _date_to_string(date)
     return el


 def _data_element(data: bytes, ctx: SimpleNamespace) -> etree.Element:
     el = etree.Element("data")
     # NOTE: mypy is confused about whether el.text should be str or bytes.
     el.text = _encode_base64(  # type: ignore
         data,
         maxlinelength=(76 if ctx.pretty_print else None),
         indent_level=ctx.indent_level,
     )
     return el


 def _string_or_data_element(raw_bytes: bytes, ctx: SimpleNamespace) -> etree.Element:
     if ctx.use_builtin_types:
         return _data_element(raw_bytes, ctx)
     else:
         try:
             string = raw_bytes.decode(encoding="ascii", errors="strict")
         except UnicodeDecodeError:
             raise ValueError(
                 "invalid non-ASCII bytes; use unicode string instead: %r" % raw_bytes
             )
         return _string_element(string, ctx)


 # The following is probably not entirely correct. The signature should take `Any`
 # and return `NoReturn`. At the time of this writing, neither mypy nor Pyright
 # can deal with singledispatch properly and will apply the signature of the base
 # function to all others. Being slightly dishonest makes it type-check and return
 # usable typing information for the optimistic case.
 @singledispatch
 def _make_element(value: PlistEncodable, ctx: SimpleNamespace) -> etree.Element:
     raise TypeError("unsupported type: %s" % type(value))


 _make_element.register(str)(_string_element)
 _make_element.register(bool)(_bool_element)
 _make_element.register(Integral)(_integer_element)
 _make_element.register(float)(_real_element)
 _make_element.register(collections.abc.Mapping)(_dict_element)
 _make_element.register(list)(_array_element)
 _make_element.register(tuple)(_array_element)
 _make_element.register(datetime)(_date_element)
 _make_element.register(bytes)(_string_or_data_element)
 _make_element.register(bytearray)(_data_element)
 _make_element.register(Data)(lambda v, ctx: _data_element(v.data, ctx))


 # Public functions to create element tree from plist-compatible python
 # data structures and viceversa, for use when (de)serializing GLIF xml.


 def totree(
     value: PlistEncodable,
     sort_keys: bool = True,
     skipkeys: bool = False,
     use_builtin_types: Optional[bool] = None,
     pretty_print: bool = True,
     indent_level: int = 1,
 ) -> etree.Element:
     """Convert a value derived from a plist into an XML tree.

     Args:
         value: Any kind of value to be serialized to XML.
         sort_keys: Whether keys of dictionaries should be sorted.
         skipkeys (bool): Whether to silently skip non-string dictionary
             keys.
         use_builtin_types (bool): If true, byte strings will be
             encoded in Base-64 and wrapped in a ``data`` tag; if
             false, they will be either stored as ASCII strings or an
             exception raised if they cannot be decoded as such. Defaults
             to ``True`` if not present. Deprecated.
         pretty_print (bool): Whether to indent the output.
         indent_level (int): Level of indentation when serializing.

     Returns: an ``etree`` ``Element`` object.

     Raises:
         ``TypeError``
             if non-string dictionary keys are serialized
             and ``skipkeys`` is false.
         ``ValueError``
             if non-ASCII binary data is present
             and `use_builtin_types` is false.
     """
     if use_builtin_types is None:
         use_builtin_types = USE_BUILTIN_TYPES
     else:
         use_builtin_types = use_builtin_types
     context = SimpleNamespace(
         sort_keys=sort_keys,
         skipkeys=skipkeys,
         use_builtin_types=use_builtin_types,
         pretty_print=pretty_print,
         indent_level=indent_level,
     )
     return _make_element(value, context)


 def fromtree(
     tree: etree.Element,
     use_builtin_types: Optional[bool] = None,
     dict_type: Type[MutableMapping[str, Any]] = dict,
 ) -> Any:
     """Convert an XML tree to a plist structure.

     Args:
         tree: An ``etree`` ``Element``.
         use_builtin_types: If True, binary data is deserialized to
             bytes strings. If False, it is wrapped in :py:class:`Data`
             objects. Defaults to True if not provided. Deprecated.
         dict_type: What type to use for dictionaries.

     Returns: An object (usually a dictionary).
     """
     target = PlistTarget(use_builtin_types=use_builtin_types, dict_type=dict_type)
     for action, element in etree.iterwalk(tree, events=("start", "end")):
         if action == "start":
             target.start(element.tag, element.attrib)
         elif action == "end":
             # if there are no children, parse the leaf's data
             if not len(element):
                 # always pass str, not None
                 target.data(element.text or "")
             target.end(element.tag)
     return target.close()


 # python3 plistlib API


 def load(
     fp: IO[bytes],
     use_builtin_types: Optional[bool] = None,
     dict_type: Type[MutableMapping[str, Any]] = dict,
 ) -> Any:
     """Load a plist file into an object.

     Args:
         fp: An opened file.
         use_builtin_types: If True, binary data is deserialized to
             bytes strings. If False, it is wrapped in :py:class:`Data`
             objects. Defaults to True if not provided. Deprecated.
         dict_type: What type to use for dictionaries.

     Returns:
         An object (usually a dictionary) representing the top level of
         the plist file.
     """

     if not hasattr(fp, "read"):
         raise AttributeError("'%s' object has no attribute 'read'" % type(fp).__name__)
     target = PlistTarget(use_builtin_types=use_builtin_types, dict_type=dict_type)
     parser = etree.XMLParser(target=target)
     result = etree.parse(fp, parser=parser)
     # lxml returns the target object directly, while ElementTree wraps
     # it as the root of an ElementTree object
     try:
         return result.getroot()
     except AttributeError:
         return result


 def loads(
     value: bytes,
     use_builtin_types: Optional[bool] = None,
     dict_type: Type[MutableMapping[str, Any]] = dict,
 ) -> Any:
     """Load a plist file from a string into an object.

     Args:
         value: A bytes string containing a plist.
         use_builtin_types: If True, binary data is deserialized to
             bytes strings. If False, it is wrapped in :py:class:`Data`
             objects. Defaults to True if not provided. Deprecated.
         dict_type: What type to use for dictionaries.

     Returns:
         An object (usually a dictionary) representing the top level of
         the plist file.
     """

     fp = BytesIO(value)
     return load(fp, use_builtin_types=use_builtin_types, dict_type=dict_type)


 def dump(
     value: PlistEncodable,
     fp: IO[bytes],
     sort_keys: bool = True,
     skipkeys: bool = False,
     use_builtin_types: Optional[bool] = None,
     pretty_print: bool = True,
 ) -> None:
     """Write a Python object to a plist file.

     Args:
         value: An object to write.
         fp: A file opened for writing.
         sort_keys (bool): Whether keys of dictionaries should be sorted.
         skipkeys (bool): Whether to silently skip non-string dictionary
             keys.
         use_builtin_types (bool): If true, byte strings will be
             encoded in Base-64 and wrapped in a ``data`` tag; if
             false, they will be either stored as ASCII strings or an
             exception raised if they cannot be represented. Defaults
         pretty_print (bool): Whether to indent the output.
         indent_level (int): Level of indentation when serializing.

     Raises:
         ``TypeError``
             if non-string dictionary keys are serialized
             and ``skipkeys`` is false.
         ``ValueError``
             if non-representable binary data is present
             and `use_builtin_types` is false.
     """

     if not hasattr(fp, "write"):
         raise AttributeError("'%s' object has no attribute 'write'" % type(fp).__name__)
     root = etree.Element("plist", version="1.0")
     el = totree(
         value,
         sort_keys=sort_keys,
         skipkeys=skipkeys,
         use_builtin_types=use_builtin_types,
         pretty_print=pretty_print,
     )
     root.append(el)
     tree = etree.ElementTree(root)
     # we write the doctype ourselves instead of using the 'doctype' argument
     # of 'write' method, becuse lxml will force adding a '\n' even when
     # pretty_print is False.
     if pretty_print:
         header = b"\n".join((XML_DECLARATION, PLIST_DOCTYPE, b""))
     else:
         header = XML_DECLARATION + PLIST_DOCTYPE
     fp.write(header)
     tree.write(  # type: ignore
         fp,
         encoding="utf-8",
         pretty_print=pretty_print,
         xml_declaration=False,
     )


 def dumps(
     value: PlistEncodable,
     sort_keys: bool = True,
     skipkeys: bool = False,
     use_builtin_types: Optional[bool] = None,
     pretty_print: bool = True,
 ) -> bytes:
     """Write a Python object to a string in plist format.

     Args:
         value: An object to write.
         sort_keys (bool): Whether keys of dictionaries should be sorted.
         skipkeys (bool): Whether to silently skip non-string dictionary
             keys.
         use_builtin_types (bool): If true, byte strings will be
             encoded in Base-64 and wrapped in a ``data`` tag; if
             false, they will be either stored as strings or an
             exception raised if they cannot be represented. Defaults
         pretty_print (bool): Whether to indent the output.
         indent_level (int): Level of indentation when serializing.

     Returns:
         string: A plist representation of the Python object.

     Raises:
         ``TypeError``
             if non-string dictionary keys are serialized
             and ``skipkeys`` is false.
         ``ValueError``
             if non-representable binary data is present
             and `use_builtin_types` is false.
     """
     fp = BytesIO()
     dump(
         value,
         fp,
         sort_keys=sort_keys,
         skipkeys=skipkeys,
         use_builtin_types=use_builtin_types,
         pretty_print=pretty_print,
     )
     return fp.getvalue()
	import collections.abc
	import re
	from typing import (
	Any,
	Callable,
	Dict,
	List,
	Mapping,
	MutableMapping,
	Optional,
	Sequence,
	Type,
	Union,
	IO,
	)
	import warnings
	from io import BytesIO
	from datetime import datetime
	from base64 import b64encode, b64decode
	from numbers import Integral
	from types import SimpleNamespace
	from functools import singledispatch

	from fontTools.misc import etree

	from fontTools.misc.py23 import tostr


	# By default, we
	# - deserialize <data> elements as bytes and
	# - serialize bytes as <data> elements.
	# Before, on Python 2, we
	# - deserialized <data> elements as plistlib.Data objects, in order to
	# distinguish them from the built-in str type (which is bytes on python2)
	# - serialized bytes as <string> elements (they must have only contained
	# ASCII characters in this case)
	# You can pass use_builtin_types=[True\|False] to the load/dump etc. functions
	# to enforce a specific treatment.
	# NOTE that unicode type always maps to <string> element, and plistlib.Data
	# always maps to <data> element, regardless of use_builtin_types.
	USE_BUILTIN_TYPES = True

	XML_DECLARATION = b"""<?xml version='1.0' encoding='UTF-8'?>"""

	PLIST_DOCTYPE = (
	b'<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" '
	b'"http://www.apple.com/DTDs/PropertyList-1.0.dtd">'
	)


	# Date should conform to a subset of ISO 8601:
	# YYYY '-' MM '-' DD 'T' HH ':' MM ':' SS 'Z'
	_date_parser = re.compile(
	r"(?P<year>\d\d\d\d)"
	r"(?:-(?P<month>\d\d)"
	r"(?:-(?P<day>\d\d)"
	r"(?:T(?P<hour>\d\d)"
	r"(?::(?P<minute>\d\d)"
	r"(?::(?P<second>\d\d))"
	r"?)?)?)?)?Z",
	re.ASCII,
	)


	def _date_from_string(s: str) -> datetime:
	order = ("year", "month", "day", "hour", "minute", "second")
	m = _date_parser.match(s)
	if m is None:
	raise ValueError(f"Expected ISO 8601 date string, but got '{s:r}'.")
	gd = m.groupdict()
	lst = []
	for key in order:
	val = gd[key]
	if val is None:
	break
	lst.append(int(val))
	# NOTE: mypy doesn't know that lst is 6 elements long.
	return datetime(*lst) # type:ignore


	def _date_to_string(d: datetime) -> str:
	return "%04d-%02d-%02dT%02d:%02d:%02dZ" % (
	d.year,
	d.month,
	d.day,
	d.hour,
	d.minute,
	d.second,
	)


	class Data:
	"""Represents binary data when ``use_builtin_types=False.``

	This class wraps binary data loaded from a plist file when the
	``use_builtin_types`` argument to the loading function (:py:func:`fromtree`,
	:py:func:`load`, :py:func:`loads`) is false.

	The actual binary data is retrieved using the ``data`` attribute.
	"""

	def __init__(self, data: bytes) -> None:
	if not isinstance(data, bytes):
	raise TypeError("Expected bytes, found %s" % type(data).__name__)
	self.data = data

	@classmethod
	def fromBase64(cls, data: Union[bytes, str]) -> "Data":
	return cls(b64decode(data))

	def asBase64(self, maxlinelength: int = 76, indent_level: int = 1) -> bytes:
	return _encode_base64(
	self.data, maxlinelength=maxlinelength, indent_level=indent_level
	)

	def __eq__(self, other: Any) -> bool:
	if isinstance(other, self.__class__):
	return self.data == other.data
	elif isinstance(other, bytes):
	return self.data == other
	else:
	return NotImplemented

	def __repr__(self) -> str:
	return "%s(%s)" % (self.__class__.__name__, repr(self.data))


	def _encode_base64(
	data: bytes, maxlinelength: Optional[int] = 76, indent_level: int = 1
	) -> bytes:
	data = b64encode(data)
	if data and maxlinelength:
	# split into multiple lines right-justified to 'maxlinelength' chars
	indent = b"\n" + b" " * indent_level
	max_length = max(16, maxlinelength - len(indent))
	chunks = []
	for i in range(0, len(data), max_length):
	chunks.append(indent)
	chunks.append(data[i : i + max_length])
	chunks.append(indent)
	data = b"".join(chunks)
	return data


	# Mypy does not support recursive type aliases as of 0.782, Pylance does.
	# https://github.com/python/mypy/issues/731
	# https://devblogs.microsoft.com/python/pylance-introduces-five-new-features-that-enable-type-magic-for-python-developers/#1-support-for-recursive-type-aliases
	PlistEncodable = Union[
	bool,
	bytes,
	Data,
	datetime,
	float,
	int,
	Mapping[str, Any],
	Sequence[Any],
	str,
	]


	class PlistTarget:
	"""Event handler using the ElementTree Target API that can be
	passed to a XMLParser to produce property list objects from XML.
	It is based on the CPython plistlib module's _PlistParser class,
	but does not use the expat parser.

	>>> from fontTools.misc import etree
	>>> parser = etree.XMLParser(target=PlistTarget())
	>>> result = etree.XML(
	... "<dict>"
	... " <key>something</key>"
	... " <string>blah</string>"
	... "</dict>",
	... parser=parser)
	>>> result == {"something": "blah"}
	True

	Links:
	https://github.com/python/cpython/blob/master/Lib/plistlib.py
	http://lxml.de/parsing.html#the-target-parser-interface
	"""

	def __init__(
	self,
	use_builtin_types: Optional[bool] = None,
	dict_type: Type[MutableMapping[str, Any]] = dict,
	) -> None:
	self.stack: List[PlistEncodable] = []
	self.current_key: Optional[str] = None
	self.root: Optional[PlistEncodable] = None
	if use_builtin_types is None:
	self._use_builtin_types = USE_BUILTIN_TYPES
	else:
	if use_builtin_types is False:
	warnings.warn(
	"Setting use_builtin_types to False is deprecated and will be "
	"removed soon.",
	DeprecationWarning,
	)
	self._use_builtin_types = use_builtin_types
	self._dict_type = dict_type

	def start(self, tag: str, attrib: Mapping[str, str]) -> None:
	self._data: List[str] = []
	handler = _TARGET_START_HANDLERS.get(tag)
	if handler is not None:
	handler(self)

	def end(self, tag: str) -> None:
	handler = _TARGET_END_HANDLERS.get(tag)
	if handler is not None:
	handler(self)

	def data(self, data: str) -> None:
	self._data.append(data)

	def close(self) -> PlistEncodable:
	if self.root is None:
	raise ValueError("No root set.")
	return self.root

	# helpers

	def add_object(self, value: PlistEncodable) -> None:
	if self.current_key is not None:
	stack_top = self.stack[-1]
	if not isinstance(stack_top, collections.abc.MutableMapping):
	raise ValueError("unexpected element: %r" % stack_top)
	stack_top[self.current_key] = value
	self.current_key = None
	elif not self.stack:
	# this is the root object
	self.root = value
	else:
	stack_top = self.stack[-1]
	if not isinstance(stack_top, list):
	raise ValueError("unexpected element: %r" % stack_top)
	stack_top.append(value)

	def get_data(self) -> str:
	data = "".join(self._data)
	self._data = []
	return data


	# event handlers


	def start_dict(self: PlistTarget) -> None:
	d = self._dict_type()
	self.add_object(d)
	self.stack.append(d)


	def end_dict(self: PlistTarget) -> None:
	if self.current_key:
	raise ValueError("missing value for key '%s'" % self.current_key)
	self.stack.pop()


	def end_key(self: PlistTarget) -> None:
	if self.current_key or not isinstance(self.stack[-1], collections.abc.Mapping):
	raise ValueError("unexpected key")
	self.current_key = self.get_data()


	def start_array(self: PlistTarget) -> None:
	a: List[PlistEncodable] = []
	self.add_object(a)
	self.stack.append(a)


	def end_array(self: PlistTarget) -> None:
	self.stack.pop()


	def end_true(self: PlistTarget) -> None:
	self.add_object(True)


	def end_false(self: PlistTarget) -> None:
	self.add_object(False)


	def end_integer(self: PlistTarget) -> None:
	self.add_object(int(self.get_data()))


	def end_real(self: PlistTarget) -> None:
	self.add_object(float(self.get_data()))


	def end_string(self: PlistTarget) -> None:
	self.add_object(self.get_data())


	def end_data(self: PlistTarget) -> None:
	if self._use_builtin_types:
	self.add_object(b64decode(self.get_data()))
	else:
	self.add_object(Data.fromBase64(self.get_data()))


	def end_date(self: PlistTarget) -> None:
	self.add_object(_date_from_string(self.get_data()))


	_TARGET_START_HANDLERS: Dict[str, Callable[[PlistTarget], None]] = {
	"dict": start_dict,
	"array": start_array,
	}

	_TARGET_END_HANDLERS: Dict[str, Callable[[PlistTarget], None]] = {
	"dict": end_dict,
	"array": end_array,
	"key": end_key,
	"true": end_true,
	"false": end_false,
	"integer": end_integer,
	"real": end_real,
	"string": end_string,
	"data": end_data,
	"date": end_date,
	}


	# functions to build element tree from plist data


	def _string_element(value: str, ctx: SimpleNamespace) -> etree.Element:
	el = etree.Element("string")
	el.text = value
	return el


	def _bool_element(value: bool, ctx: SimpleNamespace) -> etree.Element:
	if value:
	return etree.Element("true")
	return etree.Element("false")


	def _integer_element(value: int, ctx: SimpleNamespace) -> etree.Element:
	if -1 << 63 <= value < 1 << 64:
	el = etree.Element("integer")
	el.text = "%d" % value
	return el
	raise OverflowError(value)


	def _real_element(value: float, ctx: SimpleNamespace) -> etree.Element:
	el = etree.Element("real")
	el.text = repr(value)
	return el


	def _dict_element(d: Mapping[str, PlistEncodable], ctx: SimpleNamespace) -> etree.Element:
	el = etree.Element("dict")
	items = d.items()
	if ctx.sort_keys:
	items = sorted(items) # type: ignore
	ctx.indent_level += 1
	for key, value in items:
	if not isinstance(key, str):
	if ctx.skipkeys:
	continue
	raise TypeError("keys must be strings")
	k = etree.SubElement(el, "key")
	k.text = tostr(key, "utf-8")
	el.append(_make_element(value, ctx))
	ctx.indent_level -= 1
	return el


	def _array_element(array: Sequence[PlistEncodable], ctx: SimpleNamespace) -> etree.Element:
	el = etree.Element("array")
	if len(array) == 0:
	return el
	ctx.indent_level += 1
	for value in array:
	el.append(_make_element(value, ctx))
	ctx.indent_level -= 1
	return el


	def _date_element(date: datetime, ctx: SimpleNamespace) -> etree.Element:
	el = etree.Element("date")
	el.text = _date_to_string(date)
	return el


	def _data_element(data: bytes, ctx: SimpleNamespace) -> etree.Element:
	el = etree.Element("data")
	# NOTE: mypy is confused about whether el.text should be str or bytes.
	el.text = _encode_base64( # type: ignore
	data,
	maxlinelength=(76 if ctx.pretty_print else None),
	indent_level=ctx.indent_level,
	)
	return el


	def _string_or_data_element(raw_bytes: bytes, ctx: SimpleNamespace) -> etree.Element:
	if ctx.use_builtin_types:
	return _data_element(raw_bytes, ctx)
	else:
	try:
	string = raw_bytes.decode(encoding="ascii", errors="strict")
	except UnicodeDecodeError:
	raise ValueError(
	"invalid non-ASCII bytes; use unicode string instead: %r" % raw_bytes
	)
	return _string_element(string, ctx)


	# The following is probably not entirely correct. The signature should take `Any`
	# and return `NoReturn`. At the time of this writing, neither mypy nor Pyright
	# can deal with singledispatch properly and will apply the signature of the base
	# function to all others. Being slightly dishonest makes it type-check and return
	# usable typing information for the optimistic case.
	@singledispatch
	def _make_element(value: PlistEncodable, ctx: SimpleNamespace) -> etree.Element:
	raise TypeError("unsupported type: %s" % type(value))


	_make_element.register(str)(_string_element)
	_make_element.register(bool)(_bool_element)
	_make_element.register(Integral)(_integer_element)
	_make_element.register(float)(_real_element)
	_make_element.register(collections.abc.Mapping)(_dict_element)
	_make_element.register(list)(_array_element)
	_make_element.register(tuple)(_array_element)
	_make_element.register(datetime)(_date_element)
	_make_element.register(bytes)(_string_or_data_element)
	_make_element.register(bytearray)(_data_element)
	_make_element.register(Data)(lambda v, ctx: _data_element(v.data, ctx))


	# Public functions to create element tree from plist-compatible python
	# data structures and viceversa, for use when (de)serializing GLIF xml.


	def totree(
	value: PlistEncodable,
	sort_keys: bool = True,
	skipkeys: bool = False,
	use_builtin_types: Optional[bool] = None,
	pretty_print: bool = True,
	indent_level: int = 1,
	) -> etree.Element:
	"""Convert a value derived from a plist into an XML tree.

	Args:
	value: Any kind of value to be serialized to XML.
	sort_keys: Whether keys of dictionaries should be sorted.
	skipkeys (bool): Whether to silently skip non-string dictionary
	keys.
	use_builtin_types (bool): If true, byte strings will be
	encoded in Base-64 and wrapped in a ``data`` tag; if
	false, they will be either stored as ASCII strings or an
	exception raised if they cannot be decoded as such. Defaults
	to ``True`` if not present. Deprecated.
	pretty_print (bool): Whether to indent the output.
	indent_level (int): Level of indentation when serializing.

	Returns: an ``etree`` ``Element`` object.

	Raises:
	``TypeError``
	if non-string dictionary keys are serialized
	and ``skipkeys`` is false.
	``ValueError``
	if non-ASCII binary data is present
	and `use_builtin_types` is false.
	"""
	if use_builtin_types is None:
	use_builtin_types = USE_BUILTIN_TYPES
	else:
	use_builtin_types = use_builtin_types
	context = SimpleNamespace(
	sort_keys=sort_keys,
	skipkeys=skipkeys,
	use_builtin_types=use_builtin_types,
	pretty_print=pretty_print,
	indent_level=indent_level,
	)
	return _make_element(value, context)


	def fromtree(
	tree: etree.Element,
	use_builtin_types: Optional[bool] = None,
	dict_type: Type[MutableMapping[str, Any]] = dict,
	) -> Any:
	"""Convert an XML tree to a plist structure.

	Args:
	tree: An ``etree`` ``Element``.
	use_builtin_types: If True, binary data is deserialized to
	bytes strings. If False, it is wrapped in :py:class:`Data`
	objects. Defaults to True if not provided. Deprecated.
	dict_type: What type to use for dictionaries.

	Returns: An object (usually a dictionary).
	"""
	target = PlistTarget(use_builtin_types=use_builtin_types, dict_type=dict_type)
	for action, element in etree.iterwalk(tree, events=("start", "end")):
	if action == "start":
	target.start(element.tag, element.attrib)
	elif action == "end":
	# if there are no children, parse the leaf's data
	if not len(element):
	# always pass str, not None
	target.data(element.text or "")
	target.end(element.tag)
	return target.close()


	# python3 plistlib API


	def load(
	fp: IO[bytes],
	use_builtin_types: Optional[bool] = None,
	dict_type: Type[MutableMapping[str, Any]] = dict,
	) -> Any:
	"""Load a plist file into an object.

	Args:
	fp: An opened file.
	use_builtin_types: If True, binary data is deserialized to
	bytes strings. If False, it is wrapped in :py:class:`Data`
	objects. Defaults to True if not provided. Deprecated.
	dict_type: What type to use for dictionaries.

	Returns:
	An object (usually a dictionary) representing the top level of
	the plist file.
	"""

	if not hasattr(fp, "read"):
	raise AttributeError("'%s' object has no attribute 'read'" % type(fp).__name__)
	target = PlistTarget(use_builtin_types=use_builtin_types, dict_type=dict_type)
	parser = etree.XMLParser(target=target)
	result = etree.parse(fp, parser=parser)
	# lxml returns the target object directly, while ElementTree wraps
	# it as the root of an ElementTree object
	try:
	return result.getroot()
	except AttributeError:
	return result


	def loads(
	value: bytes,
	use_builtin_types: Optional[bool] = None,
	dict_type: Type[MutableMapping[str, Any]] = dict,
	) -> Any:
	"""Load a plist file from a string into an object.

	Args:
	value: A bytes string containing a plist.
	use_builtin_types: If True, binary data is deserialized to
	bytes strings. If False, it is wrapped in :py:class:`Data`
	objects. Defaults to True if not provided. Deprecated.
	dict_type: What type to use for dictionaries.

	Returns:
	An object (usually a dictionary) representing the top level of
	the plist file.
	"""

	fp = BytesIO(value)
	return load(fp, use_builtin_types=use_builtin_types, dict_type=dict_type)


	def dump(
	value: PlistEncodable,
	fp: IO[bytes],
	sort_keys: bool = True,
	skipkeys: bool = False,
	use_builtin_types: Optional[bool] = None,
	pretty_print: bool = True,
	) -> None:
	"""Write a Python object to a plist file.

	Args:
	value: An object to write.
	fp: A file opened for writing.
	sort_keys (bool): Whether keys of dictionaries should be sorted.
	skipkeys (bool): Whether to silently skip non-string dictionary
	keys.
	use_builtin_types (bool): If true, byte strings will be
	encoded in Base-64 and wrapped in a ``data`` tag; if
	false, they will be either stored as ASCII strings or an
	exception raised if they cannot be represented. Defaults
	pretty_print (bool): Whether to indent the output.
	indent_level (int): Level of indentation when serializing.

	Raises:
	``TypeError``
	if non-string dictionary keys are serialized
	and ``skipkeys`` is false.
	``ValueError``
	if non-representable binary data is present
	and `use_builtin_types` is false.
	"""

	if not hasattr(fp, "write"):
	raise AttributeError("'%s' object has no attribute 'write'" % type(fp).__name__)
	root = etree.Element("plist", version="1.0")
	el = totree(
	value,
	sort_keys=sort_keys,
	skipkeys=skipkeys,
	use_builtin_types=use_builtin_types,
	pretty_print=pretty_print,
	)
	root.append(el)
	tree = etree.ElementTree(root)
	# we write the doctype ourselves instead of using the 'doctype' argument
	# of 'write' method, becuse lxml will force adding a '\n' even when
	# pretty_print is False.
	if pretty_print:
	header = b"\n".join((XML_DECLARATION, PLIST_DOCTYPE, b""))
	else:
	header = XML_DECLARATION + PLIST_DOCTYPE
	fp.write(header)
	tree.write( # type: ignore
	fp,
	encoding="utf-8",
	pretty_print=pretty_print,
	xml_declaration=False,
	)


	def dumps(
	value: PlistEncodable,
	sort_keys: bool = True,
	skipkeys: bool = False,
	use_builtin_types: Optional[bool] = None,
	pretty_print: bool = True,
	) -> bytes:
	"""Write a Python object to a string in plist format.

	Args:
	value: An object to write.
	sort_keys (bool): Whether keys of dictionaries should be sorted.
	skipkeys (bool): Whether to silently skip non-string dictionary
	keys.
	use_builtin_types (bool): If true, byte strings will be
	encoded in Base-64 and wrapped in a ``data`` tag; if
	false, they will be either stored as strings or an
	exception raised if they cannot be represented. Defaults
	pretty_print (bool): Whether to indent the output.
	indent_level (int): Level of indentation when serializing.

	Returns:
	string: A plist representation of the Python object.

	Raises:
	``TypeError``
	if non-string dictionary keys are serialized
	and ``skipkeys`` is false.
	``ValueError``
	if non-representable binary data is present
	and `use_builtin_types` is false.
	"""
	fp = BytesIO()
	dump(
	value,
	fp,
	sort_keys=sort_keys,
	skipkeys=skipkeys,
	use_builtin_types=use_builtin_types,
	pretty_print=pretty_print,
	)
	return fp.getvalue()