1 2__all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer', 3 'RepresenterError'] 4 5from error import * 6 7from nodes import * 8 9import datetime 10 11import copy_reg, types 12 13class RepresenterError(YAMLError): 14 pass 15 16class BaseRepresenter(object): 17 18 yaml_representers = {} 19 yaml_multi_representers = {} 20 21 def __init__(self, default_style=None, default_flow_style=False, sort_keys=True): 22 self.default_style = default_style 23 self.default_flow_style = default_flow_style 24 self.sort_keys = sort_keys 25 self.represented_objects = {} 26 self.object_keeper = [] 27 self.alias_key = None 28 29 def represent(self, data): 30 node = self.represent_data(data) 31 self.serialize(node) 32 self.represented_objects = {} 33 self.object_keeper = [] 34 self.alias_key = None 35 36 def get_classobj_bases(self, cls): 37 bases = [cls] 38 for base in cls.__bases__: 39 bases.extend(self.get_classobj_bases(base)) 40 return bases 41 42 def represent_data(self, data): 43 if self.ignore_aliases(data): 44 self.alias_key = None 45 else: 46 self.alias_key = id(data) 47 if self.alias_key is not None: 48 if self.alias_key in self.represented_objects: 49 node = self.represented_objects[self.alias_key] 50 #if node is None: 51 # raise RepresenterError("recursive objects are not allowed: %r" % data) 52 return node 53 #self.represented_objects[alias_key] = None 54 self.object_keeper.append(data) 55 data_types = type(data).__mro__ 56 if type(data) is types.InstanceType: 57 data_types = self.get_classobj_bases(data.__class__)+list(data_types) 58 if data_types[0] in self.yaml_representers: 59 node = self.yaml_representers[data_types[0]](self, data) 60 else: 61 for data_type in data_types: 62 if data_type in self.yaml_multi_representers: 63 node = self.yaml_multi_representers[data_type](self, data) 64 break 65 else: 66 if None in self.yaml_multi_representers: 67 node = self.yaml_multi_representers[None](self, data) 68 elif None in self.yaml_representers: 69 node = self.yaml_representers[None](self, data) 70 else: 71 node = ScalarNode(None, unicode(data)) 72 #if alias_key is not None: 73 # self.represented_objects[alias_key] = node 74 return node 75 76 def add_representer(cls, data_type, representer): 77 if not 'yaml_representers' in cls.__dict__: 78 cls.yaml_representers = cls.yaml_representers.copy() 79 cls.yaml_representers[data_type] = representer 80 add_representer = classmethod(add_representer) 81 82 def add_multi_representer(cls, data_type, representer): 83 if not 'yaml_multi_representers' in cls.__dict__: 84 cls.yaml_multi_representers = cls.yaml_multi_representers.copy() 85 cls.yaml_multi_representers[data_type] = representer 86 add_multi_representer = classmethod(add_multi_representer) 87 88 def represent_scalar(self, tag, value, style=None): 89 if style is None: 90 style = self.default_style 91 node = ScalarNode(tag, value, style=style) 92 if self.alias_key is not None: 93 self.represented_objects[self.alias_key] = node 94 return node 95 96 def represent_sequence(self, tag, sequence, flow_style=None): 97 value = [] 98 node = SequenceNode(tag, value, flow_style=flow_style) 99 if self.alias_key is not None: 100 self.represented_objects[self.alias_key] = node 101 best_style = True 102 for item in sequence: 103 node_item = self.represent_data(item) 104 if not (isinstance(node_item, ScalarNode) and not node_item.style): 105 best_style = False 106 value.append(node_item) 107 if flow_style is None: 108 if self.default_flow_style is not None: 109 node.flow_style = self.default_flow_style 110 else: 111 node.flow_style = best_style 112 return node 113 114 def represent_mapping(self, tag, mapping, flow_style=None): 115 value = [] 116 node = MappingNode(tag, value, flow_style=flow_style) 117 if self.alias_key is not None: 118 self.represented_objects[self.alias_key] = node 119 best_style = True 120 if hasattr(mapping, 'items'): 121 mapping = mapping.items() 122 if self.sort_keys: 123 mapping.sort() 124 for item_key, item_value in mapping: 125 node_key = self.represent_data(item_key) 126 node_value = self.represent_data(item_value) 127 if not (isinstance(node_key, ScalarNode) and not node_key.style): 128 best_style = False 129 if not (isinstance(node_value, ScalarNode) and not node_value.style): 130 best_style = False 131 value.append((node_key, node_value)) 132 if flow_style is None: 133 if self.default_flow_style is not None: 134 node.flow_style = self.default_flow_style 135 else: 136 node.flow_style = best_style 137 return node 138 139 def ignore_aliases(self, data): 140 return False 141 142class SafeRepresenter(BaseRepresenter): 143 144 def ignore_aliases(self, data): 145 if data is None: 146 return True 147 if isinstance(data, tuple) and data == (): 148 return True 149 if isinstance(data, (str, unicode, bool, int, float)): 150 return True 151 152 def represent_none(self, data): 153 return self.represent_scalar(u'tag:yaml.org,2002:null', 154 u'null') 155 156 def represent_str(self, data): 157 tag = None 158 style = None 159 try: 160 data = unicode(data, 'ascii') 161 tag = u'tag:yaml.org,2002:str' 162 except UnicodeDecodeError: 163 try: 164 data = unicode(data, 'utf-8') 165 tag = u'tag:yaml.org,2002:str' 166 except UnicodeDecodeError: 167 data = data.encode('base64') 168 tag = u'tag:yaml.org,2002:binary' 169 style = '|' 170 return self.represent_scalar(tag, data, style=style) 171 172 def represent_unicode(self, data): 173 return self.represent_scalar(u'tag:yaml.org,2002:str', data) 174 175 def represent_bool(self, data): 176 if data: 177 value = u'true' 178 else: 179 value = u'false' 180 return self.represent_scalar(u'tag:yaml.org,2002:bool', value) 181 182 def represent_int(self, data): 183 return self.represent_scalar(u'tag:yaml.org,2002:int', unicode(data)) 184 185 def represent_long(self, data): 186 return self.represent_scalar(u'tag:yaml.org,2002:int', unicode(data)) 187 188 inf_value = 1e300 189 while repr(inf_value) != repr(inf_value*inf_value): 190 inf_value *= inf_value 191 192 def represent_float(self, data): 193 if data != data or (data == 0.0 and data == 1.0): 194 value = u'.nan' 195 elif data == self.inf_value: 196 value = u'.inf' 197 elif data == -self.inf_value: 198 value = u'-.inf' 199 else: 200 value = unicode(repr(data)).lower() 201 # Note that in some cases `repr(data)` represents a float number 202 # without the decimal parts. For instance: 203 # >>> repr(1e17) 204 # '1e17' 205 # Unfortunately, this is not a valid float representation according 206 # to the definition of the `!!float` tag. We fix this by adding 207 # '.0' before the 'e' symbol. 208 if u'.' not in value and u'e' in value: 209 value = value.replace(u'e', u'.0e', 1) 210 return self.represent_scalar(u'tag:yaml.org,2002:float', value) 211 212 def represent_list(self, data): 213 #pairs = (len(data) > 0 and isinstance(data, list)) 214 #if pairs: 215 # for item in data: 216 # if not isinstance(item, tuple) or len(item) != 2: 217 # pairs = False 218 # break 219 #if not pairs: 220 return self.represent_sequence(u'tag:yaml.org,2002:seq', data) 221 #value = [] 222 #for item_key, item_value in data: 223 # value.append(self.represent_mapping(u'tag:yaml.org,2002:map', 224 # [(item_key, item_value)])) 225 #return SequenceNode(u'tag:yaml.org,2002:pairs', value) 226 227 def represent_dict(self, data): 228 return self.represent_mapping(u'tag:yaml.org,2002:map', data) 229 230 def represent_set(self, data): 231 value = {} 232 for key in data: 233 value[key] = None 234 return self.represent_mapping(u'tag:yaml.org,2002:set', value) 235 236 def represent_date(self, data): 237 value = unicode(data.isoformat()) 238 return self.represent_scalar(u'tag:yaml.org,2002:timestamp', value) 239 240 def represent_datetime(self, data): 241 value = unicode(data.isoformat(' ')) 242 return self.represent_scalar(u'tag:yaml.org,2002:timestamp', value) 243 244 def represent_yaml_object(self, tag, data, cls, flow_style=None): 245 if hasattr(data, '__getstate__'): 246 state = data.__getstate__() 247 else: 248 state = data.__dict__.copy() 249 return self.represent_mapping(tag, state, flow_style=flow_style) 250 251 def represent_undefined(self, data): 252 raise RepresenterError("cannot represent an object", data) 253 254SafeRepresenter.add_representer(type(None), 255 SafeRepresenter.represent_none) 256 257SafeRepresenter.add_representer(str, 258 SafeRepresenter.represent_str) 259 260SafeRepresenter.add_representer(unicode, 261 SafeRepresenter.represent_unicode) 262 263SafeRepresenter.add_representer(bool, 264 SafeRepresenter.represent_bool) 265 266SafeRepresenter.add_representer(int, 267 SafeRepresenter.represent_int) 268 269SafeRepresenter.add_representer(long, 270 SafeRepresenter.represent_long) 271 272SafeRepresenter.add_representer(float, 273 SafeRepresenter.represent_float) 274 275SafeRepresenter.add_representer(list, 276 SafeRepresenter.represent_list) 277 278SafeRepresenter.add_representer(tuple, 279 SafeRepresenter.represent_list) 280 281SafeRepresenter.add_representer(dict, 282 SafeRepresenter.represent_dict) 283 284SafeRepresenter.add_representer(set, 285 SafeRepresenter.represent_set) 286 287SafeRepresenter.add_representer(datetime.date, 288 SafeRepresenter.represent_date) 289 290SafeRepresenter.add_representer(datetime.datetime, 291 SafeRepresenter.represent_datetime) 292 293SafeRepresenter.add_representer(None, 294 SafeRepresenter.represent_undefined) 295 296class Representer(SafeRepresenter): 297 298 def represent_str(self, data): 299 tag = None 300 style = None 301 try: 302 data = unicode(data, 'ascii') 303 tag = u'tag:yaml.org,2002:str' 304 except UnicodeDecodeError: 305 try: 306 data = unicode(data, 'utf-8') 307 tag = u'tag:yaml.org,2002:python/str' 308 except UnicodeDecodeError: 309 data = data.encode('base64') 310 tag = u'tag:yaml.org,2002:binary' 311 style = '|' 312 return self.represent_scalar(tag, data, style=style) 313 314 def represent_unicode(self, data): 315 tag = None 316 try: 317 data.encode('ascii') 318 tag = u'tag:yaml.org,2002:python/unicode' 319 except UnicodeEncodeError: 320 tag = u'tag:yaml.org,2002:str' 321 return self.represent_scalar(tag, data) 322 323 def represent_long(self, data): 324 tag = u'tag:yaml.org,2002:int' 325 if int(data) is not data: 326 tag = u'tag:yaml.org,2002:python/long' 327 return self.represent_scalar(tag, unicode(data)) 328 329 def represent_complex(self, data): 330 if data.imag == 0.0: 331 data = u'%r' % data.real 332 elif data.real == 0.0: 333 data = u'%rj' % data.imag 334 elif data.imag > 0: 335 data = u'%r+%rj' % (data.real, data.imag) 336 else: 337 data = u'%r%rj' % (data.real, data.imag) 338 return self.represent_scalar(u'tag:yaml.org,2002:python/complex', data) 339 340 def represent_tuple(self, data): 341 return self.represent_sequence(u'tag:yaml.org,2002:python/tuple', data) 342 343 def represent_name(self, data): 344 name = u'%s.%s' % (data.__module__, data.__name__) 345 return self.represent_scalar(u'tag:yaml.org,2002:python/name:'+name, u'') 346 347 def represent_module(self, data): 348 return self.represent_scalar( 349 u'tag:yaml.org,2002:python/module:'+data.__name__, u'') 350 351 def represent_instance(self, data): 352 # For instances of classic classes, we use __getinitargs__ and 353 # __getstate__ to serialize the data. 354 355 # If data.__getinitargs__ exists, the object must be reconstructed by 356 # calling cls(**args), where args is a tuple returned by 357 # __getinitargs__. Otherwise, the cls.__init__ method should never be 358 # called and the class instance is created by instantiating a trivial 359 # class and assigning to the instance's __class__ variable. 360 361 # If data.__getstate__ exists, it returns the state of the object. 362 # Otherwise, the state of the object is data.__dict__. 363 364 # We produce either a !!python/object or !!python/object/new node. 365 # If data.__getinitargs__ does not exist and state is a dictionary, we 366 # produce a !!python/object node . Otherwise we produce a 367 # !!python/object/new node. 368 369 cls = data.__class__ 370 class_name = u'%s.%s' % (cls.__module__, cls.__name__) 371 args = None 372 state = None 373 if hasattr(data, '__getinitargs__'): 374 args = list(data.__getinitargs__()) 375 if hasattr(data, '__getstate__'): 376 state = data.__getstate__() 377 else: 378 state = data.__dict__ 379 if args is None and isinstance(state, dict): 380 return self.represent_mapping( 381 u'tag:yaml.org,2002:python/object:'+class_name, state) 382 if isinstance(state, dict) and not state: 383 return self.represent_sequence( 384 u'tag:yaml.org,2002:python/object/new:'+class_name, args) 385 value = {} 386 if args: 387 value['args'] = args 388 value['state'] = state 389 return self.represent_mapping( 390 u'tag:yaml.org,2002:python/object/new:'+class_name, value) 391 392 def represent_object(self, data): 393 # We use __reduce__ API to save the data. data.__reduce__ returns 394 # a tuple of length 2-5: 395 # (function, args, state, listitems, dictitems) 396 397 # For reconstructing, we calls function(*args), then set its state, 398 # listitems, and dictitems if they are not None. 399 400 # A special case is when function.__name__ == '__newobj__'. In this 401 # case we create the object with args[0].__new__(*args). 402 403 # Another special case is when __reduce__ returns a string - we don't 404 # support it. 405 406 # We produce a !!python/object, !!python/object/new or 407 # !!python/object/apply node. 408 409 cls = type(data) 410 if cls in copy_reg.dispatch_table: 411 reduce = copy_reg.dispatch_table[cls](data) 412 elif hasattr(data, '__reduce_ex__'): 413 reduce = data.__reduce_ex__(2) 414 elif hasattr(data, '__reduce__'): 415 reduce = data.__reduce__() 416 else: 417 raise RepresenterError("cannot represent an object", data) 418 reduce = (list(reduce)+[None]*5)[:5] 419 function, args, state, listitems, dictitems = reduce 420 args = list(args) 421 if state is None: 422 state = {} 423 if listitems is not None: 424 listitems = list(listitems) 425 if dictitems is not None: 426 dictitems = dict(dictitems) 427 if function.__name__ == '__newobj__': 428 function = args[0] 429 args = args[1:] 430 tag = u'tag:yaml.org,2002:python/object/new:' 431 newobj = True 432 else: 433 tag = u'tag:yaml.org,2002:python/object/apply:' 434 newobj = False 435 function_name = u'%s.%s' % (function.__module__, function.__name__) 436 if not args and not listitems and not dictitems \ 437 and isinstance(state, dict) and newobj: 438 return self.represent_mapping( 439 u'tag:yaml.org,2002:python/object:'+function_name, state) 440 if not listitems and not dictitems \ 441 and isinstance(state, dict) and not state: 442 return self.represent_sequence(tag+function_name, args) 443 value = {} 444 if args: 445 value['args'] = args 446 if state or not isinstance(state, dict): 447 value['state'] = state 448 if listitems: 449 value['listitems'] = listitems 450 if dictitems: 451 value['dictitems'] = dictitems 452 return self.represent_mapping(tag+function_name, value) 453 454Representer.add_representer(str, 455 Representer.represent_str) 456 457Representer.add_representer(unicode, 458 Representer.represent_unicode) 459 460Representer.add_representer(long, 461 Representer.represent_long) 462 463Representer.add_representer(complex, 464 Representer.represent_complex) 465 466Representer.add_representer(tuple, 467 Representer.represent_tuple) 468 469Representer.add_representer(type, 470 Representer.represent_name) 471 472Representer.add_representer(types.ClassType, 473 Representer.represent_name) 474 475Representer.add_representer(types.FunctionType, 476 Representer.represent_name) 477 478Representer.add_representer(types.BuiltinFunctionType, 479 Representer.represent_name) 480 481Representer.add_representer(types.ModuleType, 482 Representer.represent_module) 483 484Representer.add_multi_representer(types.InstanceType, 485 Representer.represent_instance) 486 487Representer.add_multi_representer(object, 488 Representer.represent_object) 489 490