| |
| __all__ = ['BaseConstructor', 'SafeConstructor', 'Constructor', |
| 'ConstructorError'] |
| |
| from .error import * |
| from .nodes import * |
| |
| import collections, datetime, base64, binascii, re, sys, types |
| |
| class ConstructorError(MarkedYAMLError): |
| pass |
| |
| class BaseConstructor: |
| |
| yaml_constructors = {} |
| yaml_multi_constructors = {} |
| |
| def __init__(self): |
| self.constructed_objects = {} |
| self.recursive_objects = {} |
| self.state_generators = [] |
| self.deep_construct = False |
| |
| def check_data(self): |
| # If there are more documents available? |
| return self.check_node() |
| |
| def get_data(self): |
| # Construct and return the next document. |
| if self.check_node(): |
| return self.construct_document(self.get_node()) |
| |
| def get_single_data(self): |
| # Ensure that the stream contains a single document and construct it. |
| node = self.get_single_node() |
| if node is not None: |
| return self.construct_document(node) |
| return None |
| |
| def construct_document(self, node): |
| data = self.construct_object(node) |
| while self.state_generators: |
| state_generators = self.state_generators |
| self.state_generators = [] |
| for generator in state_generators: |
| for dummy in generator: |
| pass |
| self.constructed_objects = {} |
| self.recursive_objects = {} |
| self.deep_construct = False |
| return data |
| |
| def construct_object(self, node, deep=False): |
| if node in self.constructed_objects: |
| return self.constructed_objects[node] |
| if deep: |
| old_deep = self.deep_construct |
| self.deep_construct = True |
| if node in self.recursive_objects: |
| raise ConstructorError(None, None, |
| "found unconstructable recursive node", node.start_mark) |
| self.recursive_objects[node] = None |
| constructor = None |
| tag_suffix = None |
| if node.tag in self.yaml_constructors: |
| constructor = self.yaml_constructors[node.tag] |
| else: |
| for tag_prefix in self.yaml_multi_constructors: |
| if node.tag.startswith(tag_prefix): |
| tag_suffix = node.tag[len(tag_prefix):] |
| constructor = self.yaml_multi_constructors[tag_prefix] |
| break |
| else: |
| if None in self.yaml_multi_constructors: |
| tag_suffix = node.tag |
| constructor = self.yaml_multi_constructors[None] |
| elif None in self.yaml_constructors: |
| constructor = self.yaml_constructors[None] |
| elif isinstance(node, ScalarNode): |
| constructor = self.__class__.construct_scalar |
| elif isinstance(node, SequenceNode): |
| constructor = self.__class__.construct_sequence |
| elif isinstance(node, MappingNode): |
| constructor = self.__class__.construct_mapping |
| if tag_suffix is None: |
| data = constructor(self, node) |
| else: |
| data = constructor(self, tag_suffix, node) |
| if isinstance(data, types.GeneratorType): |
| generator = data |
| data = next(generator) |
| if self.deep_construct: |
| for dummy in generator: |
| pass |
| else: |
| self.state_generators.append(generator) |
| self.constructed_objects[node] = data |
| del self.recursive_objects[node] |
| if deep: |
| self.deep_construct = old_deep |
| return data |
| |
| def construct_scalar(self, node): |
| if not isinstance(node, ScalarNode): |
| raise ConstructorError(None, None, |
| "expected a scalar node, but found %s" % node.id, |
| node.start_mark) |
| return node.value |
| |
| def construct_sequence(self, node, deep=False): |
| if not isinstance(node, SequenceNode): |
| raise ConstructorError(None, None, |
| "expected a sequence node, but found %s" % node.id, |
| node.start_mark) |
| return [self.construct_object(child, deep=deep) |
| for child in node.value] |
| |
| def construct_mapping(self, node, deep=False): |
| if not isinstance(node, MappingNode): |
| raise ConstructorError(None, None, |
| "expected a mapping node, but found %s" % node.id, |
| node.start_mark) |
| mapping = {} |
| for key_node, value_node in node.value: |
| key = self.construct_object(key_node, deep=deep) |
| if not isinstance(key, collections.Hashable): |
| raise ConstructorError("while constructing a mapping", node.start_mark, |
| "found unhashable key", key_node.start_mark) |
| value = self.construct_object(value_node, deep=deep) |
| mapping[key] = value |
| return mapping |
| |
| def construct_pairs(self, node, deep=False): |
| if not isinstance(node, MappingNode): |
| raise ConstructorError(None, None, |
| "expected a mapping node, but found %s" % node.id, |
| node.start_mark) |
| pairs = [] |
| for key_node, value_node in node.value: |
| key = self.construct_object(key_node, deep=deep) |
| value = self.construct_object(value_node, deep=deep) |
| pairs.append((key, value)) |
| return pairs |
| |
| @classmethod |
| def add_constructor(cls, tag, constructor): |
| if not 'yaml_constructors' in cls.__dict__: |
| cls.yaml_constructors = cls.yaml_constructors.copy() |
| cls.yaml_constructors[tag] = constructor |
| |
| @classmethod |
| def add_multi_constructor(cls, tag_prefix, multi_constructor): |
| if not 'yaml_multi_constructors' in cls.__dict__: |
| cls.yaml_multi_constructors = cls.yaml_multi_constructors.copy() |
| cls.yaml_multi_constructors[tag_prefix] = multi_constructor |
| |
| class SafeConstructor(BaseConstructor): |
| |
| def construct_scalar(self, node): |
| if isinstance(node, MappingNode): |
| for key_node, value_node in node.value: |
| if key_node.tag == 'tag:yaml.org,2002:value': |
| return self.construct_scalar(value_node) |
| return super().construct_scalar(node) |
| |
| def flatten_mapping(self, node): |
| merge = [] |
| index = 0 |
| while index < len(node.value): |
| key_node, value_node = node.value[index] |
| if key_node.tag == 'tag:yaml.org,2002:merge': |
| del node.value[index] |
| if isinstance(value_node, MappingNode): |
| self.flatten_mapping(value_node) |
| merge.extend(value_node.value) |
| elif isinstance(value_node, SequenceNode): |
| submerge = [] |
| for subnode in value_node.value: |
| if not isinstance(subnode, MappingNode): |
| raise ConstructorError("while constructing a mapping", |
| node.start_mark, |
| "expected a mapping for merging, but found %s" |
| % subnode.id, subnode.start_mark) |
| self.flatten_mapping(subnode) |
| submerge.append(subnode.value) |
| submerge.reverse() |
| for value in submerge: |
| merge.extend(value) |
| else: |
| raise ConstructorError("while constructing a mapping", node.start_mark, |
| "expected a mapping or list of mappings for merging, but found %s" |
| % value_node.id, value_node.start_mark) |
| elif key_node.tag == 'tag:yaml.org,2002:value': |
| key_node.tag = 'tag:yaml.org,2002:str' |
| index += 1 |
| else: |
| index += 1 |
| if merge: |
| node.value = merge + node.value |
| |
| def construct_mapping(self, node, deep=False): |
| if isinstance(node, MappingNode): |
| self.flatten_mapping(node) |
| return super().construct_mapping(node, deep=deep) |
| |
| def construct_yaml_null(self, node): |
| self.construct_scalar(node) |
| return None |
| |
| bool_values = { |
| 'yes': True, |
| 'no': False, |
| 'true': True, |
| 'false': False, |
| 'on': True, |
| 'off': False, |
| } |
| |
| def construct_yaml_bool(self, node): |
| value = self.construct_scalar(node) |
| return self.bool_values[value.lower()] |
| |
| def construct_yaml_int(self, node): |
| value = self.construct_scalar(node) |
| value = value.replace('_', '') |
| sign = +1 |
| if value[0] == '-': |
| sign = -1 |
| if value[0] in '+-': |
| value = value[1:] |
| if value == '0': |
| return 0 |
| elif value.startswith('0b'): |
| return sign*int(value[2:], 2) |
| elif value.startswith('0x'): |
| return sign*int(value[2:], 16) |
| elif value[0] == '0': |
| return sign*int(value, 8) |
| elif ':' in value: |
| digits = [int(part) for part in value.split(':')] |
| digits.reverse() |
| base = 1 |
| value = 0 |
| for digit in digits: |
| value += digit*base |
| base *= 60 |
| return sign*value |
| else: |
| return sign*int(value) |
| |
| inf_value = 1e300 |
| while inf_value != inf_value*inf_value: |
| inf_value *= inf_value |
| nan_value = -inf_value/inf_value # Trying to make a quiet NaN (like C99). |
| |
| def construct_yaml_float(self, node): |
| value = self.construct_scalar(node) |
| value = value.replace('_', '').lower() |
| sign = +1 |
| if value[0] == '-': |
| sign = -1 |
| if value[0] in '+-': |
| value = value[1:] |
| if value == '.inf': |
| return sign*self.inf_value |
| elif value == '.nan': |
| return self.nan_value |
| elif ':' in value: |
| digits = [float(part) for part in value.split(':')] |
| digits.reverse() |
| base = 1 |
| value = 0.0 |
| for digit in digits: |
| value += digit*base |
| base *= 60 |
| return sign*value |
| else: |
| return sign*float(value) |
| |
| def construct_yaml_binary(self, node): |
| try: |
| value = self.construct_scalar(node).encode('ascii') |
| except UnicodeEncodeError as exc: |
| raise ConstructorError(None, None, |
| "failed to convert base64 data into ascii: %s" % exc, |
| node.start_mark) |
| try: |
| if hasattr(base64, 'decodebytes'): |
| return base64.decodebytes(value) |
| else: |
| return base64.decodestring(value) |
| except binascii.Error as exc: |
| raise ConstructorError(None, None, |
| "failed to decode base64 data: %s" % exc, node.start_mark) |
| |
| timestamp_regexp = re.compile( |
| r'''^(?P<year>[0-9][0-9][0-9][0-9]) |
| -(?P<month>[0-9][0-9]?) |
| -(?P<day>[0-9][0-9]?) |
| (?:(?:[Tt]|[ \t]+) |
| (?P<hour>[0-9][0-9]?) |
| :(?P<minute>[0-9][0-9]) |
| :(?P<second>[0-9][0-9]) |
| (?:\.(?P<fraction>[0-9]*))? |
| (?:[ \t]*(?P<tz>Z|(?P<tz_sign>[-+])(?P<tz_hour>[0-9][0-9]?) |
| (?::(?P<tz_minute>[0-9][0-9]))?))?)?$''', re.X) |
| |
| def construct_yaml_timestamp(self, node): |
| value = self.construct_scalar(node) |
| match = self.timestamp_regexp.match(node.value) |
| values = match.groupdict() |
| year = int(values['year']) |
| month = int(values['month']) |
| day = int(values['day']) |
| if not values['hour']: |
| return datetime.date(year, month, day) |
| hour = int(values['hour']) |
| minute = int(values['minute']) |
| second = int(values['second']) |
| fraction = 0 |
| if values['fraction']: |
| fraction = values['fraction'][:6] |
| while len(fraction) < 6: |
| fraction += '0' |
| fraction = int(fraction) |
| delta = None |
| if values['tz_sign']: |
| tz_hour = int(values['tz_hour']) |
| tz_minute = int(values['tz_minute'] or 0) |
| delta = datetime.timedelta(hours=tz_hour, minutes=tz_minute) |
| if values['tz_sign'] == '-': |
| delta = -delta |
| data = datetime.datetime(year, month, day, hour, minute, second, fraction) |
| if delta: |
| data -= delta |
| return data |
| |
| def construct_yaml_omap(self, node): |
| # Note: we do not check for duplicate keys, because it's too |
| # CPU-expensive. |
| omap = [] |
| yield omap |
| if not isinstance(node, SequenceNode): |
| raise ConstructorError("while constructing an ordered map", node.start_mark, |
| "expected a sequence, but found %s" % node.id, node.start_mark) |
| for subnode in node.value: |
| if not isinstance(subnode, MappingNode): |
| raise ConstructorError("while constructing an ordered map", node.start_mark, |
| "expected a mapping of length 1, but found %s" % subnode.id, |
| subnode.start_mark) |
| if len(subnode.value) != 1: |
| raise ConstructorError("while constructing an ordered map", node.start_mark, |
| "expected a single mapping item, but found %d items" % len(subnode.value), |
| subnode.start_mark) |
| key_node, value_node = subnode.value[0] |
| key = self.construct_object(key_node) |
| value = self.construct_object(value_node) |
| omap.append((key, value)) |
| |
| def construct_yaml_pairs(self, node): |
| # Note: the same code as `construct_yaml_omap`. |
| pairs = [] |
| yield pairs |
| if not isinstance(node, SequenceNode): |
| raise ConstructorError("while constructing pairs", node.start_mark, |
| "expected a sequence, but found %s" % node.id, node.start_mark) |
| for subnode in node.value: |
| if not isinstance(subnode, MappingNode): |
| raise ConstructorError("while constructing pairs", node.start_mark, |
| "expected a mapping of length 1, but found %s" % subnode.id, |
| subnode.start_mark) |
| if len(subnode.value) != 1: |
| raise ConstructorError("while constructing pairs", node.start_mark, |
| "expected a single mapping item, but found %d items" % len(subnode.value), |
| subnode.start_mark) |
| key_node, value_node = subnode.value[0] |
| key = self.construct_object(key_node) |
| value = self.construct_object(value_node) |
| pairs.append((key, value)) |
| |
| def construct_yaml_set(self, node): |
| data = set() |
| yield data |
| value = self.construct_mapping(node) |
| data.update(value) |
| |
| def construct_yaml_str(self, node): |
| return self.construct_scalar(node) |
| |
| def construct_yaml_seq(self, node): |
| data = [] |
| yield data |
| data.extend(self.construct_sequence(node)) |
| |
| def construct_yaml_map(self, node): |
| data = {} |
| yield data |
| value = self.construct_mapping(node) |
| data.update(value) |
| |
| def construct_yaml_object(self, node, cls): |
| data = cls.__new__(cls) |
| yield data |
| if hasattr(data, '__setstate__'): |
| state = self.construct_mapping(node, deep=True) |
| data.__setstate__(state) |
| else: |
| state = self.construct_mapping(node) |
| data.__dict__.update(state) |
| |
| def construct_undefined(self, node): |
| raise ConstructorError(None, None, |
| "could not determine a constructor for the tag %r" % node.tag, |
| node.start_mark) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:null', |
| SafeConstructor.construct_yaml_null) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:bool', |
| SafeConstructor.construct_yaml_bool) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:int', |
| SafeConstructor.construct_yaml_int) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:float', |
| SafeConstructor.construct_yaml_float) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:binary', |
| SafeConstructor.construct_yaml_binary) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:timestamp', |
| SafeConstructor.construct_yaml_timestamp) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:omap', |
| SafeConstructor.construct_yaml_omap) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:pairs', |
| SafeConstructor.construct_yaml_pairs) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:set', |
| SafeConstructor.construct_yaml_set) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:str', |
| SafeConstructor.construct_yaml_str) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:seq', |
| SafeConstructor.construct_yaml_seq) |
| |
| SafeConstructor.add_constructor( |
| 'tag:yaml.org,2002:map', |
| SafeConstructor.construct_yaml_map) |
| |
| SafeConstructor.add_constructor(None, |
| SafeConstructor.construct_undefined) |
| |
| class Constructor(SafeConstructor): |
| |
| def construct_python_str(self, node): |
| return self.construct_scalar(node) |
| |
| def construct_python_unicode(self, node): |
| return self.construct_scalar(node) |
| |
| def construct_python_bytes(self, node): |
| try: |
| value = self.construct_scalar(node).encode('ascii') |
| except UnicodeEncodeError as exc: |
| raise ConstructorError(None, None, |
| "failed to convert base64 data into ascii: %s" % exc, |
| node.start_mark) |
| try: |
| if hasattr(base64, 'decodebytes'): |
| return base64.decodebytes(value) |
| else: |
| return base64.decodestring(value) |
| except binascii.Error as exc: |
| raise ConstructorError(None, None, |
| "failed to decode base64 data: %s" % exc, node.start_mark) |
| |
| def construct_python_long(self, node): |
| return self.construct_yaml_int(node) |
| |
| def construct_python_complex(self, node): |
| return complex(self.construct_scalar(node)) |
| |
| def construct_python_tuple(self, node): |
| return tuple(self.construct_sequence(node)) |
| |
| def find_python_module(self, name, mark): |
| if not name: |
| raise ConstructorError("while constructing a Python module", mark, |
| "expected non-empty name appended to the tag", mark) |
| try: |
| __import__(name) |
| except ImportError as exc: |
| raise ConstructorError("while constructing a Python module", mark, |
| "cannot find module %r (%s)" % (name, exc), mark) |
| return sys.modules[name] |
| |
| def find_python_name(self, name, mark): |
| if not name: |
| raise ConstructorError("while constructing a Python object", mark, |
| "expected non-empty name appended to the tag", mark) |
| if '.' in name: |
| module_name, object_name = name.rsplit('.', 1) |
| else: |
| module_name = 'builtins' |
| object_name = name |
| try: |
| __import__(module_name) |
| except ImportError as exc: |
| raise ConstructorError("while constructing a Python object", mark, |
| "cannot find module %r (%s)" % (module_name, exc), mark) |
| module = sys.modules[module_name] |
| if not hasattr(module, object_name): |
| raise ConstructorError("while constructing a Python object", mark, |
| "cannot find %r in the module %r" |
| % (object_name, module.__name__), mark) |
| return getattr(module, object_name) |
| |
| def construct_python_name(self, suffix, node): |
| value = self.construct_scalar(node) |
| if value: |
| raise ConstructorError("while constructing a Python name", node.start_mark, |
| "expected the empty value, but found %r" % value, node.start_mark) |
| return self.find_python_name(suffix, node.start_mark) |
| |
| def construct_python_module(self, suffix, node): |
| value = self.construct_scalar(node) |
| if value: |
| raise ConstructorError("while constructing a Python module", node.start_mark, |
| "expected the empty value, but found %r" % value, node.start_mark) |
| return self.find_python_module(suffix, node.start_mark) |
| |
| def make_python_instance(self, suffix, node, |
| args=None, kwds=None, newobj=False): |
| if not args: |
| args = [] |
| if not kwds: |
| kwds = {} |
| cls = self.find_python_name(suffix, node.start_mark) |
| if newobj and isinstance(cls, type): |
| return cls.__new__(cls, *args, **kwds) |
| else: |
| return cls(*args, **kwds) |
| |
| def set_python_instance_state(self, instance, state): |
| if hasattr(instance, '__setstate__'): |
| instance.__setstate__(state) |
| else: |
| slotstate = {} |
| if isinstance(state, tuple) and len(state) == 2: |
| state, slotstate = state |
| if hasattr(instance, '__dict__'): |
| instance.__dict__.update(state) |
| elif state: |
| slotstate.update(state) |
| for key, value in slotstate.items(): |
| setattr(object, key, value) |
| |
| def construct_python_object(self, suffix, node): |
| # Format: |
| # !!python/object:module.name { ... state ... } |
| instance = self.make_python_instance(suffix, node, newobj=True) |
| yield instance |
| deep = hasattr(instance, '__setstate__') |
| state = self.construct_mapping(node, deep=deep) |
| self.set_python_instance_state(instance, state) |
| |
| def construct_python_object_apply(self, suffix, node, newobj=False): |
| # Format: |
| # !!python/object/apply # (or !!python/object/new) |
| # args: [ ... arguments ... ] |
| # kwds: { ... keywords ... } |
| # state: ... state ... |
| # listitems: [ ... listitems ... ] |
| # dictitems: { ... dictitems ... } |
| # or short format: |
| # !!python/object/apply [ ... arguments ... ] |
| # The difference between !!python/object/apply and !!python/object/new |
| # is how an object is created, check make_python_instance for details. |
| if isinstance(node, SequenceNode): |
| args = self.construct_sequence(node, deep=True) |
| kwds = {} |
| state = {} |
| listitems = [] |
| dictitems = {} |
| else: |
| value = self.construct_mapping(node, deep=True) |
| args = value.get('args', []) |
| kwds = value.get('kwds', {}) |
| state = value.get('state', {}) |
| listitems = value.get('listitems', []) |
| dictitems = value.get('dictitems', {}) |
| instance = self.make_python_instance(suffix, node, args, kwds, newobj) |
| if state: |
| self.set_python_instance_state(instance, state) |
| if listitems: |
| instance.extend(listitems) |
| if dictitems: |
| for key in dictitems: |
| instance[key] = dictitems[key] |
| return instance |
| |
| def construct_python_object_new(self, suffix, node): |
| return self.construct_python_object_apply(suffix, node, newobj=True) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/none', |
| Constructor.construct_yaml_null) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/bool', |
| Constructor.construct_yaml_bool) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/str', |
| Constructor.construct_python_str) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/unicode', |
| Constructor.construct_python_unicode) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/bytes', |
| Constructor.construct_python_bytes) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/int', |
| Constructor.construct_yaml_int) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/long', |
| Constructor.construct_python_long) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/float', |
| Constructor.construct_yaml_float) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/complex', |
| Constructor.construct_python_complex) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/list', |
| Constructor.construct_yaml_seq) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/tuple', |
| Constructor.construct_python_tuple) |
| |
| Constructor.add_constructor( |
| 'tag:yaml.org,2002:python/dict', |
| Constructor.construct_yaml_map) |
| |
| Constructor.add_multi_constructor( |
| 'tag:yaml.org,2002:python/name:', |
| Constructor.construct_python_name) |
| |
| Constructor.add_multi_constructor( |
| 'tag:yaml.org,2002:python/module:', |
| Constructor.construct_python_module) |
| |
| Constructor.add_multi_constructor( |
| 'tag:yaml.org,2002:python/object:', |
| Constructor.construct_python_object) |
| |
| Constructor.add_multi_constructor( |
| 'tag:yaml.org,2002:python/object/apply:', |
| Constructor.construct_python_object_apply) |
| |
| Constructor.add_multi_constructor( |
| 'tag:yaml.org,2002:python/object/new:', |
| Constructor.construct_python_object_new) |
| |
