| |
| __all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer', |
| 'RepresenterError'] |
| |
| from .error import * |
| from .nodes import * |
| |
| import datetime, copyreg, types, base64, collections |
| |
| class RepresenterError(YAMLError): |
| pass |
| |
| class BaseRepresenter: |
| |
| yaml_representers = {} |
| yaml_multi_representers = {} |
| |
| def __init__(self, default_style=None, default_flow_style=False, sort_keys=True): |
| self.default_style = default_style |
| self.sort_keys = sort_keys |
| self.default_flow_style = default_flow_style |
| self.represented_objects = {} |
| self.object_keeper = [] |
| self.alias_key = None |
| |
| def represent(self, data): |
| node = self.represent_data(data) |
| self.serialize(node) |
| self.represented_objects = {} |
| self.object_keeper = [] |
| self.alias_key = None |
| |
| def represent_data(self, data): |
| if self.ignore_aliases(data): |
| self.alias_key = None |
| else: |
| self.alias_key = id(data) |
| if self.alias_key is not None: |
| if self.alias_key in self.represented_objects: |
| node = self.represented_objects[self.alias_key] |
| #if node is None: |
| # raise RepresenterError("recursive objects are not allowed: %r" % data) |
| return node |
| #self.represented_objects[alias_key] = None |
| self.object_keeper.append(data) |
| data_types = type(data).__mro__ |
| if data_types[0] in self.yaml_representers: |
| node = self.yaml_representers[data_types[0]](self, data) |
| else: |
| for data_type in data_types: |
| if data_type in self.yaml_multi_representers: |
| node = self.yaml_multi_representers[data_type](self, data) |
| break |
| else: |
| if None in self.yaml_multi_representers: |
| node = self.yaml_multi_representers[None](self, data) |
| elif None in self.yaml_representers: |
| node = self.yaml_representers[None](self, data) |
| else: |
| node = ScalarNode(None, str(data)) |
| #if alias_key is not None: |
| # self.represented_objects[alias_key] = node |
| return node |
| |
| @classmethod |
| def add_representer(cls, data_type, representer): |
| if not 'yaml_representers' in cls.__dict__: |
| cls.yaml_representers = cls.yaml_representers.copy() |
| cls.yaml_representers[data_type] = representer |
| |
| @classmethod |
| def add_multi_representer(cls, data_type, representer): |
| if not 'yaml_multi_representers' in cls.__dict__: |
| cls.yaml_multi_representers = cls.yaml_multi_representers.copy() |
| cls.yaml_multi_representers[data_type] = representer |
| |
| def represent_scalar(self, tag, value, style=None): |
| if style is None: |
| style = self.default_style |
| node = ScalarNode(tag, value, style=style) |
| if self.alias_key is not None: |
| self.represented_objects[self.alias_key] = node |
| return node |
| |
| def represent_sequence(self, tag, sequence, flow_style=None): |
| value = [] |
| node = SequenceNode(tag, value, flow_style=flow_style) |
| if self.alias_key is not None: |
| self.represented_objects[self.alias_key] = node |
| best_style = True |
| for item in sequence: |
| node_item = self.represent_data(item) |
| if not (isinstance(node_item, ScalarNode) and not node_item.style): |
| best_style = False |
| value.append(node_item) |
| if flow_style is None: |
| if self.default_flow_style is not None: |
| node.flow_style = self.default_flow_style |
| else: |
| node.flow_style = best_style |
| return node |
| |
| def represent_mapping(self, tag, mapping, flow_style=None): |
| value = [] |
| node = MappingNode(tag, value, flow_style=flow_style) |
| if self.alias_key is not None: |
| self.represented_objects[self.alias_key] = node |
| best_style = True |
| if hasattr(mapping, 'items'): |
| mapping = list(mapping.items()) |
| if self.sort_keys: |
| try: |
| mapping = sorted(mapping) |
| except TypeError: |
| pass |
| for item_key, item_value in mapping: |
| node_key = self.represent_data(item_key) |
| node_value = self.represent_data(item_value) |
| if not (isinstance(node_key, ScalarNode) and not node_key.style): |
| best_style = False |
| if not (isinstance(node_value, ScalarNode) and not node_value.style): |
| best_style = False |
| value.append((node_key, node_value)) |
| if flow_style is None: |
| if self.default_flow_style is not None: |
| node.flow_style = self.default_flow_style |
| else: |
| node.flow_style = best_style |
| return node |
| |
| def ignore_aliases(self, data): |
| return False |
| |
| class SafeRepresenter(BaseRepresenter): |
| |
| def ignore_aliases(self, data): |
| if data is None: |
| return True |
| if isinstance(data, tuple) and data == (): |
| return True |
| if isinstance(data, (str, bytes, bool, int, float)): |
| return True |
| |
| def represent_none(self, data): |
| return self.represent_scalar('tag:yaml.org,2002:null', 'null') |
| |
| def represent_str(self, data): |
| return self.represent_scalar('tag:yaml.org,2002:str', data) |
| |
| def represent_binary(self, data): |
| if hasattr(base64, 'encodebytes'): |
| data = base64.encodebytes(data).decode('ascii') |
| else: |
| data = base64.encodestring(data).decode('ascii') |
| return self.represent_scalar('tag:yaml.org,2002:binary', data, style='|') |
| |
| def represent_bool(self, data): |
| if data: |
| value = 'true' |
| else: |
| value = 'false' |
| return self.represent_scalar('tag:yaml.org,2002:bool', value) |
| |
| def represent_int(self, data): |
| return self.represent_scalar('tag:yaml.org,2002:int', str(data)) |
| |
| inf_value = 1e300 |
| while repr(inf_value) != repr(inf_value*inf_value): |
| inf_value *= inf_value |
| |
| def represent_float(self, data): |
| if data != data or (data == 0.0 and data == 1.0): |
| value = '.nan' |
| elif data == self.inf_value: |
| value = '.inf' |
| elif data == -self.inf_value: |
| value = '-.inf' |
| else: |
| value = repr(data).lower() |
| # Note that in some cases `repr(data)` represents a float number |
| # without the decimal parts. For instance: |
| # >>> repr(1e17) |
| # '1e17' |
| # Unfortunately, this is not a valid float representation according |
| # to the definition of the `!!float` tag. We fix this by adding |
| # '.0' before the 'e' symbol. |
| if '.' not in value and 'e' in value: |
| value = value.replace('e', '.0e', 1) |
| return self.represent_scalar('tag:yaml.org,2002:float', value) |
| |
| def represent_list(self, data): |
| #pairs = (len(data) > 0 and isinstance(data, list)) |
| #if pairs: |
| # for item in data: |
| # if not isinstance(item, tuple) or len(item) != 2: |
| # pairs = False |
| # break |
| #if not pairs: |
| return self.represent_sequence('tag:yaml.org,2002:seq', data) |
| #value = [] |
| #for item_key, item_value in data: |
| # value.append(self.represent_mapping(u'tag:yaml.org,2002:map', |
| # [(item_key, item_value)])) |
| #return SequenceNode(u'tag:yaml.org,2002:pairs', value) |
| |
| def represent_dict(self, data): |
| return self.represent_mapping('tag:yaml.org,2002:map', data) |
| |
| def represent_set(self, data): |
| value = {} |
| for key in data: |
| value[key] = None |
| return self.represent_mapping('tag:yaml.org,2002:set', value) |
| |
| def represent_date(self, data): |
| value = data.isoformat() |
| return self.represent_scalar('tag:yaml.org,2002:timestamp', value) |
| |
| def represent_datetime(self, data): |
| value = data.isoformat(' ') |
| return self.represent_scalar('tag:yaml.org,2002:timestamp', value) |
| |
| def represent_yaml_object(self, tag, data, cls, flow_style=None): |
| if hasattr(data, '__getstate__'): |
| state = data.__getstate__() |
| else: |
| state = data.__dict__.copy() |
| return self.represent_mapping(tag, state, flow_style=flow_style) |
| |
| def represent_undefined(self, data): |
| raise RepresenterError("cannot represent an object", data) |
| |
| SafeRepresenter.add_representer(type(None), |
| SafeRepresenter.represent_none) |
| |
| SafeRepresenter.add_representer(str, |
| SafeRepresenter.represent_str) |
| |
| SafeRepresenter.add_representer(bytes, |
| SafeRepresenter.represent_binary) |
| |
| SafeRepresenter.add_representer(bool, |
| SafeRepresenter.represent_bool) |
| |
| SafeRepresenter.add_representer(int, |
| SafeRepresenter.represent_int) |
| |
| SafeRepresenter.add_representer(float, |
| SafeRepresenter.represent_float) |
| |
| SafeRepresenter.add_representer(list, |
| SafeRepresenter.represent_list) |
| |
| SafeRepresenter.add_representer(tuple, |
| SafeRepresenter.represent_list) |
| |
| SafeRepresenter.add_representer(dict, |
| SafeRepresenter.represent_dict) |
| |
| SafeRepresenter.add_representer(set, |
| SafeRepresenter.represent_set) |
| |
| SafeRepresenter.add_representer(datetime.date, |
| SafeRepresenter.represent_date) |
| |
| SafeRepresenter.add_representer(datetime.datetime, |
| SafeRepresenter.represent_datetime) |
| |
| SafeRepresenter.add_representer(None, |
| SafeRepresenter.represent_undefined) |
| |
| class Representer(SafeRepresenter): |
| |
| def represent_complex(self, data): |
| if data.imag == 0.0: |
| data = '%r' % data.real |
| elif data.real == 0.0: |
| data = '%rj' % data.imag |
| elif data.imag > 0: |
| data = '%r+%rj' % (data.real, data.imag) |
| else: |
| data = '%r%rj' % (data.real, data.imag) |
| return self.represent_scalar('tag:yaml.org,2002:python/complex', data) |
| |
| def represent_tuple(self, data): |
| return self.represent_sequence('tag:yaml.org,2002:python/tuple', data) |
| |
| def represent_name(self, data): |
| name = '%s.%s' % (data.__module__, data.__name__) |
| return self.represent_scalar('tag:yaml.org,2002:python/name:'+name, '') |
| |
| def represent_module(self, data): |
| return self.represent_scalar( |
| 'tag:yaml.org,2002:python/module:'+data.__name__, '') |
| |
| def represent_object(self, data): |
| # We use __reduce__ API to save the data. data.__reduce__ returns |
| # a tuple of length 2-5: |
| # (function, args, state, listitems, dictitems) |
| |
| # For reconstructing, we calls function(*args), then set its state, |
| # listitems, and dictitems if they are not None. |
| |
| # A special case is when function.__name__ == '__newobj__'. In this |
| # case we create the object with args[0].__new__(*args). |
| |
| # Another special case is when __reduce__ returns a string - we don't |
| # support it. |
| |
| # We produce a !!python/object, !!python/object/new or |
| # !!python/object/apply node. |
| |
| cls = type(data) |
| if cls in copyreg.dispatch_table: |
| reduce = copyreg.dispatch_table[cls](data) |
| elif hasattr(data, '__reduce_ex__'): |
| reduce = data.__reduce_ex__(2) |
| elif hasattr(data, '__reduce__'): |
| reduce = data.__reduce__() |
| else: |
| raise RepresenterError("cannot represent an object", data) |
| reduce = (list(reduce)+[None]*5)[:5] |
| function, args, state, listitems, dictitems = reduce |
| args = list(args) |
| if state is None: |
| state = {} |
| if listitems is not None: |
| listitems = list(listitems) |
| if dictitems is not None: |
| dictitems = dict(dictitems) |
| if function.__name__ == '__newobj__': |
| function = args[0] |
| args = args[1:] |
| tag = 'tag:yaml.org,2002:python/object/new:' |
| newobj = True |
| else: |
| tag = 'tag:yaml.org,2002:python/object/apply:' |
| newobj = False |
| function_name = '%s.%s' % (function.__module__, function.__name__) |
| if not args and not listitems and not dictitems \ |
| and isinstance(state, dict) and newobj: |
| return self.represent_mapping( |
| 'tag:yaml.org,2002:python/object:'+function_name, state) |
| if not listitems and not dictitems \ |
| and isinstance(state, dict) and not state: |
| return self.represent_sequence(tag+function_name, args) |
| value = {} |
| if args: |
| value['args'] = args |
| if state or not isinstance(state, dict): |
| value['state'] = state |
| if listitems: |
| value['listitems'] = listitems |
| if dictitems: |
| value['dictitems'] = dictitems |
| return self.represent_mapping(tag+function_name, value) |
| |
| def represent_ordered_dict(self, data): |
| # Provide uniform representation across different Python versions. |
| data_type = type(data) |
| tag = 'tag:yaml.org,2002:python/object/apply:%s.%s' \ |
| % (data_type.__module__, data_type.__name__) |
| items = [[key, value] for key, value in data.items()] |
| return self.represent_sequence(tag, [items]) |
| |
| Representer.add_representer(complex, |
| Representer.represent_complex) |
| |
| Representer.add_representer(tuple, |
| Representer.represent_tuple) |
| |
| Representer.add_multi_representer(type, |
| Representer.represent_name) |
| |
| Representer.add_representer(collections.OrderedDict, |
| Representer.represent_ordered_dict) |
| |
| Representer.add_representer(types.FunctionType, |
| Representer.represent_name) |
| |
| Representer.add_representer(types.BuiltinFunctionType, |
| Representer.represent_name) |
| |
| Representer.add_representer(types.ModuleType, |
| Representer.represent_module) |
| |
| Representer.add_multi_representer(object, |
| Representer.represent_object) |
| |
