__all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer', 'RepresenterError'] from error import * from nodes import * try: import datetime datetime_available = True except ImportError: datetime_available = False try: set except NameError: from sets import Set as set class RepresenterError(YAMLError): pass class BaseRepresenter: yaml_representers = {} def __init__(self): self.represented_objects = {} def represent(self, data): node = self.represent_object(data) self.serialize(node) self.represented_objects = {} def represent_object(self, data): if self.ignore_aliases(data): alias_key = None else: alias_key = id(data) if alias_key is not None: if alias_key in self.represented_objects: node = self.represented_objects[alias_key] if node is None: raise RepresenterError("recursive objects are not allowed: %r" % data) return node self.represented_objects[alias_key] = None for data_type in type(data).__mro__: if data_type in self.yaml_representers: node = self.yaml_representers[data_type](self, data) break else: if 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 represent_scalar(self, tag, value, style=None): return ScalarNode(tag, value, style=style) def represent_sequence(self, tag, sequence, flow_style=None): value = [] for item in sequence: value.append(self.represent_object(item)) return SequenceNode(tag, value, flow_style=flow_style) def represent_mapping(self, tag, mapping, flow_style=None): value = {} if hasattr(mapping, 'keys'): for item_key in mapping.keys(): item_value = mapping[item_key] value[self.represent_object(item_key)] = \ self.represent_object(item_value) else: for item_key, item_value in mapping: value[self.represent_object(item_key)] = \ self.represent_object(item_value) return MappingNode(tag, value, flow_style=flow_style) def ignore_aliases(self, data): return False class SafeRepresenter(BaseRepresenter): def ignore_aliases(self, data): if data in [None, ()]: 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): encoding = None try: unicode(data, 'ascii') encoding = 'ascii' except UnicodeDecodeError: try: unicode(data, 'utf-8') encoding = 'utf-8' except UnicodeDecodeError: pass if encoding: return self.represent_scalar(u'tag:yaml.org,2002:str', unicode(data, encoding)) else: return self.represent_scalar(u'tag:yaml.org,2002:binary', unicode(data.encode('base64')), 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 = 1e300000 nan_value = inf_value/inf_value def represent_float(self, data): if data == self.inf_value: value = u'.inf' elif data == -self.inf_value: value = u'-.inf' elif data == self.nan_value or data != data: value = u'.nan' else: value = unicode(data) return self.represent_scalar(u'tag:yaml.org,2002:float', value) def represent_list(self, data): pairs = (len(data) > 0) 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 = u'%04d-%02d-%02d' % (data.year, data.month, data.day) return self.represent_scalar(u'tag:yaml.org,2002:timestamp', value) def represent_datetime(self, data): value = u'%04d-%02d-%02d %02d:%02d:%02d' \ % (data.year, data.month, data.day, data.hour, data.minute, data.second) if data.microsecond: value += u'.' + unicode(data.microsecond/1000000.0).split(u'.')[1] if data.utcoffset(): value += unicode(data.utcoffset()) 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() mapping = state if hasattr(state, 'keys'): mapping = [] keys = state.keys() keys.sort() for key in keys: mapping.append((key.replace('_', '-'), state[key])) return self.represent_mapping(tag, mapping, flow_style=flow_style) def represent_undefined(self, data): raise RepresenterError("cannot represent an object: %s" % 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(dict, SafeRepresenter.represent_dict) SafeRepresenter.add_representer(set, SafeRepresenter.represent_set) if datetime_available: 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): pass