diff options
Diffstat (limited to 'yaml/lib/yaml/representer.py')
| -rw-r--r-- | yaml/lib/yaml/representer.py | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/yaml/lib/yaml/representer.py b/yaml/lib/yaml/representer.py new file mode 100644 index 0000000000..93e09b67b3 --- /dev/null +++ b/yaml/lib/yaml/representer.py @@ -0,0 +1,489 @@ + +__all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer', + 'RepresenterError'] + +from error import * + +from nodes import * + +import datetime + +import copy_reg, types + +class RepresenterError(YAMLError): + pass + +class BaseRepresenter(object): + + yaml_representers = {} + yaml_multi_representers = {} + + def __init__(self, default_style=None, default_flow_style=False, sort_keys=True): + self.default_style = default_style + self.default_flow_style = default_flow_style + self.sort_keys = sort_keys + 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 get_classobj_bases(self, cls): + bases = [cls] + for base in cls.__bases__: + bases.extend(self.get_classobj_bases(base)) + return bases + + 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 type(data) is types.InstanceType: + data_types = self.get_classobj_bases(data.__class__)+list(data_types) + 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, unicode(data)) + #if alias_key is not None: + # self.represented_objects[alias_key] = node + return node + + 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 + add_representer = classmethod(add_representer) + + 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 + add_multi_representer = classmethod(add_multi_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 = mapping.items() + if self.sort_keys: + mapping.sort() + 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, unicode, bool, int, float)): + return True + + def represent_none(self, data): + return self.represent_scalar(u'tag:yaml.org,2002:null', + u'null') + + def represent_str(self, data): + tag = None + style = None + try: + data = unicode(data, 'ascii') + tag = u'tag:yaml.org,2002:str' + except UnicodeDecodeError: + try: + data = unicode(data, 'utf-8') + tag = u'tag:yaml.org,2002:str' + except UnicodeDecodeError: + data = data.encode('base64') + tag = u'tag:yaml.org,2002:binary' + style = '|' + return self.represent_scalar(tag, data, style=style) + + def represent_unicode(self, data): + return self.represent_scalar(u'tag:yaml.org,2002:str', data) + + def represent_bool(self, data): + if data: + value = u'true' + else: + value = u'false' + return self.represent_scalar(u'tag:yaml.org,2002:bool', value) + + def represent_int(self, data): + return self.represent_scalar(u'tag:yaml.org,2002:int', unicode(data)) + + def represent_long(self, data): + return self.represent_scalar(u'tag:yaml.org,2002:int', unicode(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 = u'.nan' + elif data == self.inf_value: + value = u'.inf' + elif data == -self.inf_value: + value = u'-.inf' + else: + value = unicode(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 u'.' not in value and u'e' in value: + value = value.replace(u'e', u'.0e', 1) + return self.represent_scalar(u'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(u'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(u'tag:yaml.org,2002:map', data) + + def represent_set(self, data): + value = {} + for key in data: + value[key] = None + return self.represent_mapping(u'tag:yaml.org,2002:set', value) + + def represent_date(self, data): + value = unicode(data.isoformat()) + return self.represent_scalar(u'tag:yaml.org,2002:timestamp', value) + + def represent_datetime(self, data): + value = unicode(data.isoformat(' ')) + return self.represent_scalar(u'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(unicode, + SafeRepresenter.represent_unicode) + +SafeRepresenter.add_representer(bool, + SafeRepresenter.represent_bool) + +SafeRepresenter.add_representer(int, + SafeRepresenter.represent_int) + +SafeRepresenter.add_representer(long, + SafeRepresenter.represent_long) + +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_str(self, data): + tag = None + style = None + try: + data = unicode(data, 'ascii') + tag = u'tag:yaml.org,2002:str' + except UnicodeDecodeError: + try: + data = unicode(data, 'utf-8') + tag = u'tag:yaml.org,2002:python/str' + except UnicodeDecodeError: + data = data.encode('base64') + tag = u'tag:yaml.org,2002:binary' + style = '|' + return self.represent_scalar(tag, data, style=style) + + def represent_unicode(self, data): + tag = None + try: + data.encode('ascii') + tag = u'tag:yaml.org,2002:python/unicode' + except UnicodeEncodeError: + tag = u'tag:yaml.org,2002:str' + return self.represent_scalar(tag, data) + + def represent_long(self, data): + tag = u'tag:yaml.org,2002:int' + if int(data) is not data: + tag = u'tag:yaml.org,2002:python/long' + return self.represent_scalar(tag, unicode(data)) + + def represent_complex(self, data): + if data.imag == 0.0: + data = u'%r' % data.real + elif data.real == 0.0: + data = u'%rj' % data.imag + elif data.imag > 0: + data = u'%r+%rj' % (data.real, data.imag) + else: + data = u'%r%rj' % (data.real, data.imag) + return self.represent_scalar(u'tag:yaml.org,2002:python/complex', data) + + def represent_tuple(self, data): + return self.represent_sequence(u'tag:yaml.org,2002:python/tuple', data) + + def represent_name(self, data): + name = u'%s.%s' % (data.__module__, data.__name__) + return self.represent_scalar(u'tag:yaml.org,2002:python/name:'+name, u'') + + def represent_module(self, data): + return self.represent_scalar( + u'tag:yaml.org,2002:python/module:'+data.__name__, u'') + + def represent_instance(self, data): + # For instances of classic classes, we use __getinitargs__ and + # __getstate__ to serialize the data. + + # If data.__getinitargs__ exists, the object must be reconstructed by + # calling cls(**args), where args is a tuple returned by + # __getinitargs__. Otherwise, the cls.__init__ method should never be + # called and the class instance is created by instantiating a trivial + # class and assigning to the instance's __class__ variable. + + # If data.__getstate__ exists, it returns the state of the object. + # Otherwise, the state of the object is data.__dict__. + + # We produce either a !!python/object or !!python/object/new node. + # If data.__getinitargs__ does not exist and state is a dictionary, we + # produce a !!python/object node . Otherwise we produce a + # !!python/object/new node. + + cls = data.__class__ + class_name = u'%s.%s' % (cls.__module__, cls.__name__) + args = None + state = None + if hasattr(data, '__getinitargs__'): + args = list(data.__getinitargs__()) + if hasattr(data, '__getstate__'): + state = data.__getstate__() + else: + state = data.__dict__ + if args is None and isinstance(state, dict): + return self.represent_mapping( + u'tag:yaml.org,2002:python/object:'+class_name, state) + if isinstance(state, dict) and not state: + return self.represent_sequence( + u'tag:yaml.org,2002:python/object/new:'+class_name, args) + value = {} + if args: + value['args'] = args + value['state'] = state + return self.represent_mapping( + u'tag:yaml.org,2002:python/object/new:'+class_name, value) + + 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 copy_reg.dispatch_table: + reduce = copy_reg.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 = u'tag:yaml.org,2002:python/object/new:' + newobj = True + else: + tag = u'tag:yaml.org,2002:python/object/apply:' + newobj = False + function_name = u'%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( + u'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) + +Representer.add_representer(str, + Representer.represent_str) + +Representer.add_representer(unicode, + Representer.represent_unicode) + +Representer.add_representer(long, + Representer.represent_long) + +Representer.add_representer(complex, + Representer.represent_complex) + +Representer.add_representer(tuple, + Representer.represent_tuple) + +Representer.add_representer(type, + Representer.represent_name) + +Representer.add_representer(types.ClassType, + Representer.represent_name) + +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(types.InstanceType, + Representer.represent_instance) + +Representer.add_multi_representer(object, + Representer.represent_object) + |