summaryrefslogtreecommitdiffstats
path: root/python/pyyaml/lib/yaml/representer.py
diff options
context:
space:
mode:
Diffstat (limited to 'python/pyyaml/lib/yaml/representer.py')
-rw-r--r--python/pyyaml/lib/yaml/representer.py484
1 files changed, 484 insertions, 0 deletions
diff --git a/python/pyyaml/lib/yaml/representer.py b/python/pyyaml/lib/yaml/representer.py
new file mode 100644
index 000000000..5f4fc70db
--- /dev/null
+++ b/python/pyyaml/lib/yaml/representer.py
@@ -0,0 +1,484 @@
+
+__all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer',
+ 'RepresenterError']
+
+from error import *
+from nodes import *
+
+import datetime
+
+import sys, copy_reg, types
+
+class RepresenterError(YAMLError):
+ pass
+
+class BaseRepresenter(object):
+
+ yaml_representers = {}
+ yaml_multi_representers = {}
+
+ def __init__(self, default_style=None, default_flow_style=None):
+ self.default_style = default_style
+ 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 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()
+ 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 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):
+ 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: %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(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 object: %r" % 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)
+