python.d/python_modules/pyyaml3/representer.py

   1
   2 __all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer',
   3     'RepresenterError']
   4
   5 from .error import *
   6 from .nodes import *
   7
   8 import datetime, sys, copyreg, types, base64
   9
  10 class RepresenterError(YAMLError):
  11     pass
  12
  13 class BaseRepresenter:
  14
  15     yaml_representers = {}
  16     yaml_multi_representers = {}
  17
  18     def __init__(self, default_style=None, default_flow_style=None):
  19         self.default_style = default_style
  20         self.default_flow_style = default_flow_style
  21         self.represented_objects = {}
  22         self.object_keeper = []
  23         self.alias_key = None
  24
  25     def represent(self, data):
  26         node = self.represent_data(data)
  27         self.serialize(node)
  28         self.represented_objects = {}
  29         self.object_keeper = []
  30         self.alias_key = None
  31
  32     def represent_data(self, data):
  33         if self.ignore_aliases(data):
  34             self.alias_key = None
  35         else:
  36             self.alias_key = id(data)
  37         if self.alias_key is not None:
  38             if self.alias_key in self.represented_objects:
  39                 node = self.represented_objects[self.alias_key]
  40                 #if node is None:
  41                 #    raise RepresenterError("recursive objects are not allowed: %r" % data)
  42                 return node
  43             #self.represented_objects[alias_key] = None
  44             self.object_keeper.append(data)
  45         data_types = type(data).__mro__
  46         if data_types[0] in self.yaml_representers:
  47             node = self.yaml_representers[data_types[0]](self, data)
  48         else:
  49             for data_type in data_types:
  50                 if data_type in self.yaml_multi_representers:
  51                     node = self.yaml_multi_representers[data_type](self, data)
  52                     break
  53             else:
  54                 if None in self.yaml_multi_representers:
  55                     node = self.yaml_multi_representers[None](self, data)
  56                 elif None in self.yaml_representers:
  57                     node = self.yaml_representers[None](self, data)
  58                 else:
  59                     node = ScalarNode(None, str(data))
  60         #if alias_key is not None:
  61         #    self.represented_objects[alias_key] = node
  62         return node
  63
  64     @classmethod
  65     def add_representer(cls, data_type, representer):
  66         if not 'yaml_representers' in cls.__dict__:
  67             cls.yaml_representers = cls.yaml_representers.copy()
  68         cls.yaml_representers[data_type] = representer
  69
  70     @classmethod
  71     def add_multi_representer(cls, data_type, representer):
  72         if not 'yaml_multi_representers' in cls.__dict__:
  73             cls.yaml_multi_representers = cls.yaml_multi_representers.copy()
  74         cls.yaml_multi_representers[data_type] = representer
  75
  76     def represent_scalar(self, tag, value, style=None):
  77         if style is None:
  78             style = self.default_style
  79         node = ScalarNode(tag, value, style=style)
  80         if self.alias_key is not None:
  81             self.represented_objects[self.alias_key] = node
  82         return node
  83
  84     def represent_sequence(self, tag, sequence, flow_style=None):
  85         value = []
  86         node = SequenceNode(tag, value, flow_style=flow_style)
  87         if self.alias_key is not None:
  88             self.represented_objects[self.alias_key] = node
  89         best_style = True
  90         for item in sequence:
  91             node_item = self.represent_data(item)
  92             if not (isinstance(node_item, ScalarNode) and not node_item.style):
  93                 best_style = False
  94             value.append(node_item)
  95         if flow_style is None:
  96             if self.default_flow_style is not None:
  97                 node.flow_style = self.default_flow_style
  98             else:
  99                 node.flow_style = best_style
 100         return node
 101
 102     def represent_mapping(self, tag, mapping, flow_style=None):
 103         value = []
 104         node = MappingNode(tag, value, flow_style=flow_style)
 105         if self.alias_key is not None:
 106             self.represented_objects[self.alias_key] = node
 107         best_style = True
 108         if hasattr(mapping, 'items'):
 109             mapping = list(mapping.items())
 110             try:
 111                 mapping = sorted(mapping)
 112             except TypeError:
 113                 pass
 114         for item_key, item_value in mapping:
 115             node_key = self.represent_data(item_key)
 116             node_value = self.represent_data(item_value)
 117             if not (isinstance(node_key, ScalarNode) and not node_key.style):
 118                 best_style = False
 119             if not (isinstance(node_value, ScalarNode) and not node_value.style):
 120                 best_style = False
 121             value.append((node_key, node_value))
 122         if flow_style is None:
 123             if self.default_flow_style is not None:
 124                 node.flow_style = self.default_flow_style
 125             else:
 126                 node.flow_style = best_style
 127         return node
 128
 129     def ignore_aliases(self, data):
 130         return False
 131
 132 class SafeRepresenter(BaseRepresenter):
 133
 134     def ignore_aliases(self, data):
 135         if data in [None, ()]:
 136             return True
 137         if isinstance(data, (str, bytes, bool, int, float)):
 138             return True
 139
 140     def represent_none(self, data):
 141         return self.represent_scalar('tag:yaml.org,2002:null', 'null')
 142
 143     def represent_str(self, data):
 144         return self.represent_scalar('tag:yaml.org,2002:str', data)
 145
 146     def represent_binary(self, data):
 147         if hasattr(base64, 'encodebytes'):
 148             data = base64.encodebytes(data).decode('ascii')
 149         else:
 150             data = base64.encodestring(data).decode('ascii')
 151         return self.represent_scalar('tag:yaml.org,2002:binary', data, style='|')
 152
 153     def represent_bool(self, data):
 154         if data:
 155             value = 'true'
 156         else:
 157             value = 'false'
 158         return self.represent_scalar('tag:yaml.org,2002:bool', value)
 159
 160     def represent_int(self, data):
 161         return self.represent_scalar('tag:yaml.org,2002:int', str(data))
 162
 163     inf_value = 1e300
 164     while repr(inf_value) != repr(inf_value*inf_value):
 165         inf_value *= inf_value
 166
 167     def represent_float(self, data):
 168         if data != data or (data == 0.0 and data == 1.0):
 169             value = '.nan'
 170         elif data == self.inf_value:
 171             value = '.inf'
 172         elif data == -self.inf_value:
 173             value = '-.inf'
 174         else:
 175             value = repr(data).lower()
 176             # Note that in some cases `repr(data)` represents a float number
 177             # without the decimal parts.  For instance:
 178             #   >>> repr(1e17)
 179             #   '1e17'
 180             # Unfortunately, this is not a valid float representation according
 181             # to the definition of the `!!float` tag.  We fix this by adding
 182             # '.0' before the 'e' symbol.
 183             if '.' not in value and 'e' in value:
 184                 value = value.replace('e', '.0e', 1)
 185         return self.represent_scalar('tag:yaml.org,2002:float', value)
 186
 187     def represent_list(self, data):
 188         #pairs = (len(data) > 0 and isinstance(data, list))
 189         #if pairs:
 190         #    for item in data:
 191         #        if not isinstance(item, tuple) or len(item) != 2:
 192         #            pairs = False
 193         #            break
 194         #if not pairs:
 195             return self.represent_sequence('tag:yaml.org,2002:seq', data)
 196         #value = []
 197         #for item_key, item_value in data:
 198         #    value.append(self.represent_mapping(u'tag:yaml.org,2002:map',
 199         #        [(item_key, item_value)]))
 200         #return SequenceNode(u'tag:yaml.org,2002:pairs', value)
 201
 202     def represent_dict(self, data):
 203         return self.represent_mapping('tag:yaml.org,2002:map', data)
 204
 205     def represent_set(self, data):
 206         value = {}
 207         for key in data:
 208             value[key] = None
 209         return self.represent_mapping('tag:yaml.org,2002:set', value)
 210
 211     def represent_date(self, data):
 212         value = data.isoformat()
 213         return self.represent_scalar('tag:yaml.org,2002:timestamp', value)
 214
 215     def represent_datetime(self, data):
 216         value = data.isoformat(' ')
 217         return self.represent_scalar('tag:yaml.org,2002:timestamp', value)
 218
 219     def represent_yaml_object(self, tag, data, cls, flow_style=None):
 220         if hasattr(data, '__getstate__'):
 221             state = data.__getstate__()
 222         else:
 223             state = data.__dict__.copy()
 224         return self.represent_mapping(tag, state, flow_style=flow_style)
 225
 226     def represent_undefined(self, data):
 227         raise RepresenterError("cannot represent an object: %s" % data)
 228
 229 SafeRepresenter.add_representer(type(None),
 230         SafeRepresenter.represent_none)
 231
 232 SafeRepresenter.add_representer(str,
 233         SafeRepresenter.represent_str)
 234
 235 SafeRepresenter.add_representer(bytes,
 236         SafeRepresenter.represent_binary)
 237
 238 SafeRepresenter.add_representer(bool,
 239         SafeRepresenter.represent_bool)
 240
 241 SafeRepresenter.add_representer(int,
 242         SafeRepresenter.represent_int)
 243
 244 SafeRepresenter.add_representer(float,
 245         SafeRepresenter.represent_float)
 246
 247 SafeRepresenter.add_representer(list,
 248         SafeRepresenter.represent_list)
 249
 250 SafeRepresenter.add_representer(tuple,
 251         SafeRepresenter.represent_list)
 252
 253 SafeRepresenter.add_representer(dict,
 254         SafeRepresenter.represent_dict)
 255
 256 SafeRepresenter.add_representer(set,
 257         SafeRepresenter.represent_set)
 258
 259 SafeRepresenter.add_representer(datetime.date,
 260         SafeRepresenter.represent_date)
 261
 262 SafeRepresenter.add_representer(datetime.datetime,
 263         SafeRepresenter.represent_datetime)
 264
 265 SafeRepresenter.add_representer(None,
 266         SafeRepresenter.represent_undefined)
 267
 268 class Representer(SafeRepresenter):
 269
 270     def represent_complex(self, data):
 271         if data.imag == 0.0:
 272             data = '%r' % data.real
 273         elif data.real == 0.0:
 274             data = '%rj' % data.imag
 275         elif data.imag > 0:
 276             data = '%r+%rj' % (data.real, data.imag)
 277         else:
 278             data = '%r%rj' % (data.real, data.imag)
 279         return self.represent_scalar('tag:yaml.org,2002:python/complex', data)
 280
 281     def represent_tuple(self, data):
 282         return self.represent_sequence('tag:yaml.org,2002:python/tuple', data)
 283
 284     def represent_name(self, data):
 285         name = '%s.%s' % (data.__module__, data.__name__)
 286         return self.represent_scalar('tag:yaml.org,2002:python/name:'+name, '')
 287
 288     def represent_module(self, data):
 289         return self.represent_scalar(
 290                 'tag:yaml.org,2002:python/module:'+data.__name__, '')
 291
 292     def represent_object(self, data):
 293         # We use __reduce__ API to save the data. data.__reduce__ returns
 294         # a tuple of length 2-5:
 295         #   (function, args, state, listitems, dictitems)
 296
 297         # For reconstructing, we calls function(*args), then set its state,
 298         # listitems, and dictitems if they are not None.
 299
 300         # A special case is when function.__name__ == '__newobj__'. In this
 301         # case we create the object with args[0].__new__(*args).
 302
 303         # Another special case is when __reduce__ returns a string - we don't
 304         # support it.
 305
 306         # We produce a !!python/object, !!python/object/new or
 307         # !!python/object/apply node.
 308
 309         cls = type(data)
 310         if cls in copyreg.dispatch_table:
 311             reduce = copyreg.dispatch_table[cls](data)
 312         elif hasattr(data, '__reduce_ex__'):
 313             reduce = data.__reduce_ex__(2)
 314         elif hasattr(data, '__reduce__'):
 315             reduce = data.__reduce__()
 316         else:
 317             raise RepresenterError("cannot represent object: %r" % data)
 318         reduce = (list(reduce)+[None]*5)[:5]
 319         function, args, state, listitems, dictitems = reduce
 320         args = list(args)
 321         if state is None:
 322             state = {}
 323         if listitems is not None:
 324             listitems = list(listitems)
 325         if dictitems is not None:
 326             dictitems = dict(dictitems)
 327         if function.__name__ == '__newobj__':
 328             function = args[0]
 329             args = args[1:]
 330             tag = 'tag:yaml.org,2002:python/object/new:'
 331             newobj = True
 332         else:
 333             tag = 'tag:yaml.org,2002:python/object/apply:'
 334             newobj = False
 335         function_name = '%s.%s' % (function.__module__, function.__name__)
 336         if not args and not listitems and not dictitems \
 337                 and isinstance(state, dict) and newobj:
 338             return self.represent_mapping(
 339                     'tag:yaml.org,2002:python/object:'+function_name, state)
 340         if not listitems and not dictitems  \
 341                 and isinstance(state, dict) and not state:
 342             return self.represent_sequence(tag+function_name, args)
 343         value = {}
 344         if args:
 345             value['args'] = args
 346         if state or not isinstance(state, dict):
 347             value['state'] = state
 348         if listitems:
 349             value['listitems'] = listitems
 350         if dictitems:
 351             value['dictitems'] = dictitems
 352         return self.represent_mapping(tag+function_name, value)
 353
 354 Representer.add_representer(complex,
 355         Representer.represent_complex)
 356
 357 Representer.add_representer(tuple,
 358         Representer.represent_tuple)
 359
 360 Representer.add_representer(type,
 361         Representer.represent_name)
 362
 363 Representer.add_representer(types.FunctionType,
 364         Representer.represent_name)
 365
 366 Representer.add_representer(types.BuiltinFunctionType,
 367         Representer.represent_name)
 368
 369 Representer.add_representer(types.ModuleType,
 370         Representer.represent_module)
 371
 372 Representer.add_multi_representer(object,
 373         Representer.represent_object)
 374