from error import * from tokens import * from events import * from nodes import * from loader import * from dumper import * __version__ = '5.4.1' try: from cyaml import * __with_libyaml__ = True except ImportError: __with_libyaml__ = False #------------------------------------------------------------------------------ # Warnings control #------------------------------------------------------------------------------ # 'Global' warnings state: _warnings_enabled = { 'YAMLLoadWarning': True, } # Get or set global warnings' state def warnings(settings=None): if settings is None: return _warnings_enabled if type(settings) is dict: for key in settings: if key in _warnings_enabled: _warnings_enabled[key] = settings[key] # Warn when load() is called without Loader=... class YAMLLoadWarning(RuntimeWarning): pass def load_warning(method): if _warnings_enabled['YAMLLoadWarning'] is False: return import warnings message = ( "calling yaml.%s() without Loader=... is deprecated, as the " "default Loader is unsafe. Please read " "https://msg.pyyaml.org/load for full details." ) % method warnings.warn(message, YAMLLoadWarning, stacklevel=3) #------------------------------------------------------------------------------ def scan(stream, Loader=Loader): """ Scan a YAML stream and produce scanning tokens. """ loader = Loader(stream) try: while loader.check_token(): yield loader.get_token() finally: loader.dispose() def parse(stream, Loader=Loader): """ Parse a YAML stream and produce parsing events. """ loader = Loader(stream) try: while loader.check_event(): yield loader.get_event() finally: loader.dispose() def compose(stream, Loader=Loader): """ Parse the first YAML document in a stream and produce the corresponding representation tree. """ loader = Loader(stream) try: return loader.get_single_node() finally: loader.dispose() def compose_all(stream, Loader=Loader): """ Parse all YAML documents in a stream and produce corresponding representation trees. """ loader = Loader(stream) try: while loader.check_node(): yield loader.get_node() finally: loader.dispose() def load(stream, Loader=None): """ Parse the first YAML document in a stream and produce the corresponding Python object. """ if Loader is None: load_warning('load') Loader = FullLoader loader = Loader(stream) try: return loader.get_single_data() finally: loader.dispose() def load_all(stream, Loader=None): """ Parse all YAML documents in a stream and produce corresponding Python objects. """ if Loader is None: load_warning('load_all') Loader = FullLoader loader = Loader(stream) try: while loader.check_data(): yield loader.get_data() finally: loader.dispose() def full_load(stream): """ Parse the first YAML document in a stream and produce the corresponding Python object. Resolve all tags except those known to be unsafe on untrusted input. """ return load(stream, FullLoader) def full_load_all(stream): """ Parse all YAML documents in a stream and produce corresponding Python objects. Resolve all tags except those known to be unsafe on untrusted input. """ return load_all(stream, FullLoader) def safe_load(stream): """ Parse the first YAML document in a stream and produce the corresponding Python object. Resolve only basic YAML tags. This is known to be safe for untrusted input. """ return load(stream, SafeLoader) def safe_load_all(stream): """ Parse all YAML documents in a stream and produce corresponding Python objects. Resolve only basic YAML tags. This is known to be safe for untrusted input. """ return load_all(stream, SafeLoader) def unsafe_load(stream): """ Parse the first YAML document in a stream and produce the corresponding Python object. Resolve all tags, even those known to be unsafe on untrusted input. """ return load(stream, UnsafeLoader) def unsafe_load_all(stream): """ Parse all YAML documents in a stream and produce corresponding Python objects. Resolve all tags, even those known to be unsafe on untrusted input. """ return load_all(stream, UnsafeLoader) def emit(events, stream=None, Dumper=Dumper, canonical=None, indent=None, width=None, allow_unicode=None, line_break=None): """ Emit YAML parsing events into a stream. If stream is None, return the produced string instead. """ getvalue = None if stream is None: from StringIO import StringIO stream = StringIO() getvalue = stream.getvalue dumper = Dumper(stream, canonical=canonical, indent=indent, width=width, allow_unicode=allow_unicode, line_break=line_break) try: for event in events: dumper.emit(event) finally: dumper.dispose() if getvalue: return getvalue() def serialize_all(nodes, stream=None, Dumper=Dumper, canonical=None, indent=None, width=None, allow_unicode=None, line_break=None, encoding='utf-8', explicit_start=None, explicit_end=None, version=None, tags=None): """ Serialize a sequence of representation trees into a YAML stream. If stream is None, return the produced string instead. """ getvalue = None if stream is None: if encoding is None: from StringIO import StringIO else: from cStringIO import StringIO stream = StringIO() getvalue = stream.getvalue dumper = Dumper(stream, canonical=canonical, indent=indent, width=width, allow_unicode=allow_unicode, line_break=line_break, encoding=encoding, version=version, tags=tags, explicit_start=explicit_start, explicit_end=explicit_end) try: dumper.open() for node in nodes: dumper.serialize(node) dumper.close() finally: dumper.dispose() if getvalue: return getvalue() def serialize(node, stream=None, Dumper=Dumper, **kwds): """ Serialize a representation tree into a YAML stream. If stream is None, return the produced string instead. """ return serialize_all([node], stream, Dumper=Dumper, **kwds) def dump_all(documents, stream=None, Dumper=Dumper, default_style=None, default_flow_style=False, canonical=None, indent=None, width=None, allow_unicode=None, line_break=None, encoding='utf-8', explicit_start=None, explicit_end=None, version=None, tags=None, sort_keys=True): """ Serialize a sequence of Python objects into a YAML stream. If stream is None, return the produced string instead. """ getvalue = None if stream is None: if encoding is None: from StringIO import StringIO else: from cStringIO import StringIO stream = StringIO() getvalue = stream.getvalue dumper = Dumper(stream, default_style=default_style, default_flow_style=default_flow_style, canonical=canonical, indent=indent, width=width, allow_unicode=allow_unicode, line_break=line_break, encoding=encoding, version=version, tags=tags, explicit_start=explicit_start, explicit_end=explicit_end, sort_keys=sort_keys) try: dumper.open() for data in documents: dumper.represent(data) dumper.close() finally: dumper.dispose() if getvalue: return getvalue() def dump(data, stream=None, Dumper=Dumper, **kwds): """ Serialize a Python object into a YAML stream. If stream is None, return the produced string instead. """ return dump_all([data], stream, Dumper=Dumper, **kwds) def safe_dump_all(documents, stream=None, **kwds): """ Serialize a sequence of Python objects into a YAML stream. Produce only basic YAML tags. If stream is None, return the produced string instead. """ return dump_all(documents, stream, Dumper=SafeDumper, **kwds) def safe_dump(data, stream=None, **kwds): """ Serialize a Python object into a YAML stream. Produce only basic YAML tags. If stream is None, return the produced string instead. """ return dump_all([data], stream, Dumper=SafeDumper, **kwds) def add_implicit_resolver(tag, regexp, first=None, Loader=None, Dumper=Dumper): """ Add an implicit scalar detector. If an implicit scalar value matches the given regexp, the corresponding tag is assigned to the scalar. first is a sequence of possible initial characters or None. """ if Loader is None: loader.Loader.add_implicit_resolver(tag, regexp, first) loader.FullLoader.add_implicit_resolver(tag, regexp, first) loader.UnsafeLoader.add_implicit_resolver(tag, regexp, first) else: Loader.add_implicit_resolver(tag, regexp, first) Dumper.add_implicit_resolver(tag, regexp, first) def add_path_resolver(tag, path, kind=None, Loader=None, Dumper=Dumper): """ Add a path based resolver for the given tag. A path is a list of keys that forms a path to a node in the representation tree. Keys can be string values, integers, or None. """ if Loader is None: loader.Loader.add_path_resolver(tag, path, kind) loader.FullLoader.add_path_resolver(tag, path, kind) loader.UnsafeLoader.add_path_resolver(tag, path, kind) else: Loader.add_path_resolver(tag, path, kind) Dumper.add_path_resolver(tag, path, kind) def add_constructor(tag, constructor, Loader=None): """ Add a constructor for the given tag. Constructor is a function that accepts a Loader instance and a node object and produces the corresponding Python object. """ if Loader is None: loader.Loader.add_constructor(tag, constructor) loader.FullLoader.add_constructor(tag, constructor) loader.UnsafeLoader.add_constructor(tag, constructor) else: Loader.add_constructor(tag, constructor) def add_multi_constructor(tag_prefix, multi_constructor, Loader=None): """ Add a multi-constructor for the given tag prefix. Multi-constructor is called for a node if its tag starts with tag_prefix. Multi-constructor accepts a Loader instance, a tag suffix, and a node object and produces the corresponding Python object. """ if Loader is None: loader.Loader.add_multi_constructor(tag_prefix, multi_constructor) loader.FullLoader.add_multi_constructor(tag_prefix, multi_constructor) loader.UnsafeLoader.add_multi_constructor(tag_prefix, multi_constructor) else: Loader.add_multi_constructor(tag_prefix, multi_constructor) def add_representer(data_type, representer, Dumper=Dumper): """ Add a representer for the given type. Representer is a function accepting a Dumper instance and an instance of the given data type and producing the corresponding representation node. """ Dumper.add_representer(data_type, representer) def add_multi_representer(data_type, multi_representer, Dumper=Dumper): """ Add a representer for the given type. Multi-representer is a function accepting a Dumper instance and an instance of the given data type or subtype and producing the corresponding representation node. """ Dumper.add_multi_representer(data_type, multi_representer) class YAMLObjectMetaclass(type): """ The metaclass for YAMLObject. """ def __init__(cls, name, bases, kwds): super(YAMLObjectMetaclass, cls).__init__(name, bases, kwds) if 'yaml_tag' in kwds and kwds['yaml_tag'] is not None: if isinstance(cls.yaml_loader, list): for loader in cls.yaml_loader: loader.add_constructor(cls.yaml_tag, cls.from_yaml) else: cls.yaml_loader.add_constructor(cls.yaml_tag, cls.from_yaml) cls.yaml_dumper.add_representer(cls, cls.to_yaml) class YAMLObject(object): """ An object that can dump itself to a YAML stream and load itself from a YAML stream. """ __metaclass__ = YAMLObjectMetaclass __slots__ = () # no direct instantiation, so allow immutable subclasses yaml_loader = [Loader, FullLoader, UnsafeLoader] yaml_dumper = Dumper yaml_tag = None yaml_flow_style = None def from_yaml(cls, loader, node): """ Convert a representation node to a Python object. """ return loader.construct_yaml_object(node, cls) from_yaml = classmethod(from_yaml) def to_yaml(cls, dumper, data): """ Convert a Python object to a representation node. """ return dumper.represent_yaml_object(cls.yaml_tag, data, cls, flow_style=cls.yaml_flow_style) to_yaml = classmethod(to_yaml)