Current File : //snap/core20/2318/lib/python3/dist-packages/yaml/__init__.py
from .error import *
from .tokens import *
from .events import *
from .nodes import *
from .loader import *
from .dumper import *
__version__ = '5.3.1'
try:
from .cyaml import *
__with_libyaml__ = True
except ImportError:
__with_libyaml__ = False
import io
#------------------------------------------------------------------------------
# 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:
stream = io.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=None, 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:
stream = io.StringIO()
else:
stream = io.BytesIO()
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=None, 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:
stream = io.StringIO()
else:
stream = io.BytesIO()
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(metaclass=YAMLObjectMetaclass):
"""
An object that can dump itself to a YAML stream
and load itself from a YAML stream.
"""
__slots__ = () # no direct instantiation, so allow immutable subclasses
yaml_loader = [Loader, FullLoader, UnsafeLoader]
yaml_dumper = Dumper
yaml_tag = None
yaml_flow_style = None
@classmethod
def from_yaml(cls, loader, node):
"""
Convert a representation node to a Python object.
"""
return loader.construct_yaml_object(node, cls)
@classmethod
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)
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