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-
- __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_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)
-
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