GeezerVisonThe World Wide Web, restored to 800 pixels of glory. |
| Home|About|Gaming cabinet|Archives|How it works|Starter sites |
GeezerVison is showing github.com — cpython/Lib/enum.py at 3.15 · python/cpython Expand file tree/ Copy pathenum.pyMore file actions 2198 lines (2013 loc) · 84.6 KB / Copy pathenum.pyFile metadata and controls2198 lines (2013 loc) · 84.6 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 import sys import builtins as bltns from types import MappingProxyType, DynamicClassAttribute __all__ = [ 'EnumType', 'EnumMeta', 'EnumDict', 'Enum', 'IntEnum', 'StrEnum', 'Flag', 'IntFlag', 'ReprEnum', 'auto', 'unique', 'property', 'verify', 'member', 'nonmember', 'FlagBoundary', 'STRICT', 'CONFORM', 'EJECT', 'KEEP', 'global_flag_repr', 'global_enum_repr', 'global_str', 'global_enum', 'EnumCheck', 'CONTINUOUS', 'NAMED_FLAGS', 'UNIQUE', 'pickle_by_global_name', 'pickle_by_enum_name', 'show_flag_values', 'bin', ] # Dummy value for Enum and Flag as there are explicit checks for them # before they have been created. # This is also why there are checks in EnumType like `if Enum is not None` Enum = Flag = EJECT = ReprEnum = None class nonmember(object): """ Protects item from becoming an Enum member during class creation. """ def __init__(self, value): self.value = value class member(object): """ Forces item to become an Enum member during class creation. """ def __init__(self, value): self.value = value def _is_descriptor(obj): """ Returns True if obj is a descriptor, False otherwise. """ return ( hasattr(obj, '__get__') or hasattr(obj, '__set__') or hasattr(obj, '__delete__') ) def _is_dunder(name): """ Returns True if a __dunder__ name, False otherwise. """ return ( len(name) > 4 and name[:2] == name[-2:] == '__' and name[2] != '_' and name[-3] != '_' ) def _is_sunder(name): """ Returns True if a _sunder_ name, False otherwise. """ return ( len(name) > 2 and name[0] == name[-1] == '_' and name[1] != '_' and name[-2] != '_' ) def _is_internal_class(cls_name, obj): # do not use `re` as `re` imports `enum` if not isinstance(obj, type): return False qualname = getattr(obj, '__qualname__', '') s_pattern = cls_name + '.' + getattr(obj, '__name__', '') e_pattern = '.' + s_pattern return qualname == s_pattern or qualname.endswith(e_pattern) def _is_private(cls_name, name): # do not use `re` as `re` imports `enum` pattern = '_%s__' % (cls_name, ) pat_len = len(pattern) if ( len(name) > pat_len and name.startswith(pattern) and (name[-1] != '_' or name[-2] != '_') ): return True else: return False def _is_single_bit(num): """ True if only one bit set in num (should be an int) """ if num == 0: return False num &= num - 1 return num == 0 def _make_class_unpicklable(obj): """ Make the given obj un-picklable. obj should be either a dictionary, or an Enum """ def _break_on_call_reduce(self, proto): raise TypeError('%r cannot be pickled' % self) if isinstance(obj, dict): obj['__reduce_ex__'] = _break_on_call_reduce obj['__module__'] = '<unknown>' else: setattr(obj, '__reduce_ex__', _break_on_call_reduce) setattr(obj, '__module__', '<unknown>') def _iter_bits_lsb(num): # num must be a positive integer original = num if isinstance(num, Enum): num = num.value if num < 0: raise ValueError('%r is not a positive integer' % original) while num: b = num & (~num + 1) yield b num ^= b def show_flag_values(value): return list(_iter_bits_lsb(value)) def bin(num, max_bits=None): """ Like built-in bin(), except negative values are represented in twos-complement, and the leading bit always indicates sign (0=positive, 1=negative). >>> bin(10) '0b0 1010' >>> bin(~10) # ~10 is -11 '0b1 0101' """ num = num.__index__() ceiling = 2 ** (num).bit_length() if num >= 0: s = bltns.bin(num + ceiling).replace('1', '0', 1) else: s = bltns.bin(~num ^ (ceiling - 1) + ceiling) sign = s[:3] digits = s[3:] if max_bits is not None: if len(digits) < max_bits: digits = (sign[-1] * max_bits + digits)[-max_bits:] return "%s %s" % (sign, digits) class _not_given: def __repr__(self): return('<not given>') _not_given = _not_given() class _auto_null: def __repr__(self): return '_auto_null' _auto_null = _auto_null() class auto: """ Instances are replaced with an appropriate value in Enum class suites. """ def __init__(self, value=_auto_null): self.value = value def __repr__(self): return "auto(%r)" % self.value class property(DynamicClassAttribute): """ This is a descriptor, used to define attributes that act differently when accessed through an enum member and through an enum class. Instance access is the same as property(), but access to an attribute through the enum class will instead look in the class' _member_map_ for a corresponding enum member. """ member = None _attr_type = None _cls_type = None def __get__(self, instance, ownerclass=None): if instance is None: if self.member is not None: return self.member else: raise AttributeError( '%r has no attribute %r' % (ownerclass, self.name) ) if self.fget is not None: # use previous enum.property return self.fget(instance) elif self._attr_type == 'attr': # look up previous attribute return getattr(self._cls_type, self.name) elif self._attr_type == 'desc': # use previous descriptor return getattr(instance._value_, self.name) # look for a member by this name. try: return ownerclass._member_map_[self.name] except KeyError: raise AttributeError( '%r has no attribute %r' % (ownerclass, self.name) ) from None def __set__(self, instance, value): if self.fset is not None: return self.fset(instance, value) raise AttributeError( "<enum %r> cannot set attribute %r" % (self.clsname, self.name) ) def __delete__(self, instance): if self.fdel is not None: return self.fdel(instance) raise AttributeError( "<enum %r> cannot delete attribute %r" % (self.clsname, self.name) ) def __set_name__(self, ownerclass, name): self.name = name self.clsname = ownerclass.__name__ class _proto_member: """ intermediate step for enum members between class execution and final creation """ def __init__(self, value): self.value = value def __set_name__(self, enum_class, member_name): """ convert each quasi-member into an instance of the new enum class """ # first step: remove ourself from enum_class delattr(enum_class, member_name) # second step: create member based on enum_class value = self.value if not isinstance(value, tuple): args = (value, ) else: args = value if enum_class._member_type_ is tuple: # special case for tuple enums args = (args, ) # wrap it one more time if not enum_class._use_args_: enum_member = enum_class._new_member_(enum_class) else: enum_member = enum_class._new_member_(enum_class, *args) if not hasattr(enum_member, '_value_'): if enum_class._member_type_ is object: enum_member._value_ = value else: try: enum_member._value_ = enum_class._member_type_(*args) except Exception as exc: new_exc = TypeError( '_value_ not set in __new__, unable to create it' ) new_exc.__cause__ = exc raise new_exc value = enum_member._value_ enum_member._name_ = member_name enum_member.__objclass__ = enum_class enum_member.__init__(*args) enum_member._sort_order_ = len(enum_class._member_names_) if Flag is not None and issubclass(enum_class, Flag): if isinstance(value, int): enum_class._flag_mask_ |= value if _is_single_bit(value): enum_class._singles_mask_ |= value enum_class._all_bits_ = 2 ** ((enum_class._flag_mask_).bit_length()) - 1 # If another member with the same value was already defined, the # new member becomes an alias to the existing one. try: try: # try to do a fast lookup to avoid the quadratic loop enum_member = enum_class._value2member_map_[value] except TypeError: for name, canonical_member in enum_class._member_map_.items(): if canonical_member._value_ == value: enum_member = canonical_member break else: raise KeyError except KeyError: # this could still be an alias if the value is multi-bit and the # class is a flag class if ( Flag is None or not issubclass(enum_class, Flag) ): # no other instances found, record this member in _member_names_ enum_class._member_names_.append(member_name) elif ( Flag is not None and issubclass(enum_class, Flag) and isinstance(value, int) and _is_single_bit(value) ): # no other instances found, record this member in _member_names_ enum_class._member_names_.append(member_name) enum_class._add_member_(member_name, enum_member) try: # This may fail if value is not hashable. We can't add the value # to the map, and by-value lookups for this value will be # linear. enum_class._value2member_map_.setdefault(value, enum_member) if value not in enum_class._hashable_values_: enum_class._hashable_values_.append(value) except TypeError: # keep track of the value in a list so containment checks are quick enum_class._unhashable_values_.append(value) enum_class._unhashable_values_map_.setdefault(member_name, []).append(value) class EnumDict(dict): """ Track enum member order and ensure member names are not reused. EnumType will use the names found in self._member_names as the enumeration member names. """ def __init__(self, cls_name=None): super().__init__() self._member_names = {} # use a dict -- faster look-up than a list, and keeps insertion order since 3.7 self._last_values = [] self._ignore = [] self._auto_called = False self._cls_name = cls_name def __setitem__(self, key, value): """ Changes anything not dundered or not a descriptor. If an enum member name is used twice, an error is raised; duplicate values are not checked for. Single underscore (sunder) names are reserved. """ if self._cls_name is not None and _is_private(self._cls_name, key): # do nothing, name will be a normal attribute pass elif _is_sunder(key): if key not in ( '_order_', '_generate_next_value_', '_numeric_repr_', '_missing_', '_ignore_', '_iter_member_', '_iter_member_by_value_', '_iter_member_by_def_', '_add_alias_', '_add_value_alias_', # While not in use internally, those are common for pretty # printing and thus excluded from Enum's reservation of # _sunder_ names ) and not key.startswith('_repr_'): raise ValueError( '_sunder_ names, such as %r, are reserved for future Enum use' % (key, ) ) if key == '_generate_next_value_': # check if members already defined as auto() if self._auto_called: raise TypeError("_generate_next_value_ must be defined before members") _gnv = value.__func__ if isinstance(value, staticmethod) else value setattr(self, '_generate_next_value', _gnv) elif key == '_ignore_': if isinstance(value, str): value = value.replace(',',' ').split() else: value = list(value) self._ignore = value already = set(value) & set(self._member_names) if already: raise ValueError( '_ignore_ cannot specify already set names: %r' % (already, ) ) elif _is_dunder(key): if key == '__order__': key = '_order_' elif key in self._member_names: # descriptor overwriting an enum? raise TypeError('%r already defined as %r' % (key, self[key])) elif key in self._ignore: pass elif isinstance(value, nonmember): # unwrap value here; it won't be processed by the below `else` value = value.value elif _is_descriptor(value): pass elif self._cls_name is not None and _is_internal_class(self._cls_name, value): # do nothing, name will be a normal attribute pass else: if key in self: # enum overwriting a descriptor? raise TypeError('%r already defined as %r' % (key, self[key])) elif isinstance(value, member): # unwrap value here -- it will become a member value = value.value non_auto_store = True single = False if isinstance(value, auto): single = True value = (value, ) if isinstance(value, tuple) and any(isinstance(v, auto) for v in value): # insist on an actual tuple, no subclasses, in keeping with only supporting # top-level auto() usage (not contained in any other data structure) auto_valued = [] t = type(value) for v in value: if isinstance(v, auto): non_auto_store = False if v.value == _auto_null: v.value = self._generate_next_value( key, 1, len(self._member_names), self._last_values[:], ) self._auto_called = True v = v.value self._last_values.append(v) auto_valued.append(v) if single: value = auto_valued[0] else: try: # accepts iterable as multiple arguments? value = t(auto_valued) except TypeError: # then pass them in singly value = t(*auto_valued) self._member_names[key] = None if non_auto_store: self._last_values.append(value) super().__setitem__(key, value) @property def member_names(self): return list(self._member_names) def update(self, members, **more_members): try: for name in members.keys(): self[name] = members[name] except AttributeError: for name, value in members: self[name] = value for name, value in more_members.items(): self[name] = value _EnumDict = EnumDict # keep private name for backwards compatibility class EnumType(type): """ Metaclass for Enum """ @classmethod def __prepare__(metacls, cls, bases, **kwds): # check that previous enum members do not exist metacls._check_for_existing_members_(cls, bases) # create the namespace dict enum_dict = EnumDict(cls) # inherit previous flags and _generate_next_value_ function member_type, first_enum = metacls._get_mixins_(cls, bases) if first_enum is not None: enum_dict['_generate_next_value_'] = getattr( first_enum, '_generate_next_value_', None, ) return enum_dict def __new__(metacls, cls, bases, classdict, *, boundary=None, _simple=False, **kwds): # an Enum class is final once enumeration items have been defined; it # cannot be mixed with other types (int, float, etc.) if it has an # inherited __new__ unless a new __new__ is defined (or the resulting # class will fail). # if _simple: return super().__new__(metacls, cls, bases, classdict, **kwds) # # remove any keys listed in _ignore_ classdict.setdefault('_ignore_', []).append('_ignore_') ignore = classdict['_ignore_'] for key in ignore: classdict.pop(key, None) # # grab member names member_names = classdict._member_names # # check for illegal enum names (any others?) invalid_names = set(member_names) & {'mro', ''} if invalid_names: raise ValueError('invalid enum member name(s) %s' % ( ','.join(repr(n) for n in invalid_names) )) # # adjust the sunders _order_ = classdict.pop('_order_', None) _gnv = classdict.get('_generate_next_value_') if _gnv is not None and type(_gnv) is not staticmethod: _gnv = staticmethod(_gnv) # convert to normal dict classdict = dict(classdict.items()) if _gnv is not None: classdict['_generate_next_value_'] = _gnv # # data type of member and the controlling Enum class member_type, first_enum = metacls._get_mixins_(cls, bases) __new__, save_new, use_args = metacls._find_new_( classdict, member_type, first_enum, ) classdict['_new_member_'] = __new__ classdict['_use_args_'] = use_args # # convert future enum members into temporary _proto_members for name in member_names: value = classdict[name] classdict[name] = _proto_member(value) # # house-keeping structures classdict['_member_names_'] = [] classdict['_member_map_'] = {} classdict['_value2member_map_'] = {} classdict['_hashable_values_'] = [] # for comparing with non-hashable types classdict['_unhashable_values_'] = [] # e.g. frozenset() with set() classdict['_unhashable_values_map_'] = {} classdict['_member_type_'] = member_type # now set the __repr__ for the value classdict['_value_repr_'] = metacls._find_data_repr_(cls, bases) # # Flag structures (will be removed if final class is not a Flag) classdict['_boundary_'] = ( boundary or getattr(first_enum, '_boundary_', None) ) classdict['_flag_mask_'] = 0 classdict['_singles_mask_'] = 0 classdict['_all_bits_'] = 0 classdict['_inverted_'] = None # check for negative flag values and invert if found (using _proto_members) if Flag is not None and bases and issubclass(bases[-1], Flag): bits = 0 inverted = [] for n in member_names: p = classdict[n] if isinstance(p.value, int): if p.value < 0: inverted.append(p) else: bits |= p.value elif p.value is None: pass elif isinstance(p.value, tuple) and p.value and isinstance(p.value[0], int): if p.value[0] < 0: inverted.append(p) else: bits |= p.value[0] for p in inverted: if isinstance(p.value, int): p.value = bits & p.value else: p.value = (bits & p.value[0], ) + p.value[1:] try: classdict['_%s__in_progress' % cls] = True enum_class = super().__new__(metacls, cls, bases, classdict, **kwds) classdict['_%s__in_progress' % cls] = False delattr(enum_class, '_%s__in_progress' % cls) except Exception as e: # since 3.12 the note "Error calling __set_name__ on '_proto_member' instance ..." # is tacked on to the error instead of raising a RuntimeError, so discard it if hasattr(e, '__notes__'): del e.__notes__ raise # update classdict with any changes made by __init_subclass__ classdict.update(enum_class.__dict__) # # double check that repr and friends are not the mixin's or various # things break (such as pickle) # however, if the method is defined in the Enum itself, don't replace # it # # Also, special handling for ReprEnum if ReprEnum is not None and ReprEnum in bases: if member_type is object: raise TypeError( 'ReprEnum subclasses must be mixed with a data type (i.e.' ' int, str, float, etc.)' ) if '__format__' not in classdict: enum_class.__format__ = member_type.__format__ classdict['__format__'] = enum_class.__format__ if '__str__' not in classdict: method = member_type.__str__ if method is object.__str__: # if member_type does not define __str__, object.__str__ will use # its __repr__ instead, so we'll also use its __repr__ method = member_type.__repr__ enum_class.__str__ = method classdict['__str__'] = enum_class.__str__ for name in ('__repr__', '__str__', '__format__', '__reduce_ex__'): if name not in classdict: # check for mixin overrides before replacing enum_method = getattr(first_enum, name) found_method = getattr(enum_class, name) object_method = getattr(object, name) data_type_method = getattr(member_type, name) if found_method in (data_type_method, object_method): setattr(enum_class, name, enum_method) # # for Flag, add __or__, __and__, __xor__, and __invert__ if Flag is not None and issubclass(enum_class, Flag): for name in ( '__or__', '__and__', '__xor__', '__ror__', '__rand__', '__rxor__', '__invert__' ): if name not in classdict: enum_method = getattr(Flag, name) setattr(enum_class, name, enum_method) classdict[name] = enum_method # # replace any other __new__ with our own (as long as Enum is not None, # anyway) -- again, this is to support pickle if Enum is not None: # if the user defined their own __new__, save it before it gets # clobbered in case they subclass later if save_new: enum_class.__new_member__ = __new__ enum_class.__new__ = Enum.__new__ # # py3 support for definition order (helps keep py2/py3 code in sync) # # _order_ checking is spread out into three/four steps # - if enum_class is a Flag: # - remove any non-single-bit flags from _order_ # - remove any aliases from _order_ # - check that _order_ and _member_names_ match # # step 1: ensure we have a list if _order_ is not None: if isinstance(_order_, str): _order_ = _order_.replace(',', ' ').split() # # remove Flag structures if final class is not a Flag if ( Flag is None and cls != 'Flag' or Flag is not None and not issubclass(enum_class, Flag) ): delattr(enum_class, '_boundary_') delattr(enum_class, '_flag_mask_') delattr(enum_class, '_singles_mask_') delattr(enum_class, '_all_bits_') delattr(enum_class, '_inverted_') elif Flag is not None and issubclass(enum_class, Flag): # set correct __iter__ member_list = [m._value_ for m in enum_class] if member_list != sorted(member_list): enum_class._iter_member_ = enum_class._iter_member_by_def_ if _order_: # _order_ step 2: remove any items from _order_ that are not single-bit _order_ = [ o for o in _order_ if o not in enum_class._member_map_ or _is_single_bit(enum_class[o]._value_) ] # if _order_: # _order_ step 3: remove aliases from _order_ _order_ = [ o for o in _order_ if ( o not in enum_class._member_map_ or (o in enum_class._member_map_ and o in enum_class._member_names_) )] # _order_ step 4: verify that _order_ and _member_names_ match if _order_ != enum_class._member_names_: raise TypeError( 'member order does not match _order_:\n %r\n %r' % (enum_class._member_names_, _order_) ) # return enum_class def __bool__(cls): """ classes/types should always be True. """ return True def __call__(cls, value, names=_not_given, *values, module=None, qualname=None, type=None, start=1, boundary=None): """ Either returns an existing member, or creates a new enum class. This method is used both when an enum class is given a value to match to an enumeration member (i.e. Color(3)) and for the functional API (i.e. Color = Enum('Color', names='RED GREEN BLUE')). The value lookup branch is chosen if the enum is final. When used for the functional API: `value` will be the name of the new class. `names` should be either a string of white-space/comma delimited names (values will start at `start`), or an iterator/mapping of name, value pairs. `module` should be set to the module this class is being created in; if it is not set, an attempt to find that module will be made, but if it fails the class will not be picklable. `qualname` should be set to the actual location this class can be found at in its module; by default it is set to the global scope. If this is not correct, unpickling will fail in some circumstances. `type`, if set, will be mixed in as the first base class. """ if cls._member_map_: # simple value lookup if members exist if names is not _not_given: value = (value, names) + values return cls.__new__(cls, value) # otherwise, functional API: we're creating a new Enum type if names is _not_given and type is None: # no body? no data-type? possibly wrong usage raise TypeError( f"{cls} has no members; specify `names=()` if you meant to create a new, empty, enum" ) return cls._create_( class_name=value, names=None if names is _not_given else names, module=module, qualname=qualname, type=type, start=start, boundary=boundary, ) def __contains__(cls, value): """Return True if `value` is in `cls`. `value` is in `cls` if: 1) `value` is a member of `cls`, or 2) `value` is the value of one of the `cls`'s members. 3) `value` is a pseudo-member (flags) """ if isinstance(value, cls): return True if issubclass(cls, Flag): try: result = cls._missing_(value) return isinstance(result, cls) except ValueError: pass return ( value in cls._unhashable_values_ # both structures are lists or value in cls._hashable_values_ ) def __delattr__(cls, attr): # nicer error message when someone tries to delete an attribute # (see issue19025). if attr in cls._member_map_: raise AttributeError("%r cannot delete member %r." % (cls.__name__, attr)) super().__delattr__(attr) def __dir__(cls): if issubclass(cls, Flag): members = list(cls._member_map_.keys()) else: members = cls._member_names_ interesting = set([ '__class__', '__contains__', '__doc__', '__getitem__', '__iter__', '__len__', '__members__', '__module__', '__name__', '__qualname__', ] + members ) if cls._new_member_ is not object.__new__: interesting.add('__new__') if cls.__init_subclass__ is not object.__init_subclass__: interesting.add('__init_subclass__') if cls._member_type_ is object: return sorted(interesting) else: # return whatever mixed-in data type has return sorted(set(dir(cls._member_type_)) | interesting) def __getitem__(cls, name): """ Return the member matching `name`. """ return cls._member_map_[name] def __iter__(cls): """ Return members in definition order. """ return (cls._member_map_[name] for name in cls._member_names_) def __len__(cls): """ Return the number of members (no aliases) """ return len(cls._member_names_) @bltns.property def __members__(cls): """ Returns a mapping of member name->value. This mapping lists all enum members, including aliases. Note that this is a read-only view of the internal mapping. """ return MappingProxyType(cls._member_map_) def __repr__(cls): if Flag is not None and issubclass(cls, Flag): return "<flag %r>" % cls.__name__ else: return "<enum %r>" % cls.__name__ def __reversed__(cls): """ Return members in reverse definition order. """ return (cls._member_map_[name] for name in reversed(cls._member_names_)) def __setattr__(cls, name, value): """ Block attempts to reassign Enum members. A simple assignment to the class namespace only changes one of the several possible ways to get an Enum member from the Enum class, resulting in an inconsistent Enumeration. """ member_map = cls.__dict__.get('_member_map_', {}) if name in member_map: raise AttributeError('cannot reassign member %r' % (name, )) super().__setattr__(name, value) def _create_(cls, class_name, names, *, module=None, qualname=None, type=None, start=1, boundary=None): """ Convenience method to create a new Enum class. `names` can be: * A string containing member names, separated either with spaces or commas. Values are incremented by 1 from `start`. * An iterable of member names. Values are incremented by 1 from `start`. * An iterable of (member name, value) pairs. * A mapping of member name -> value pairs. """ metacls = cls.__class__ bases = (cls, ) if type is None else (type, cls) _, first_enum = cls._get_mixins_(class_name, bases) classdict = metacls.__prepare__(class_name, bases) # special processing needed for names? if isinstance(names, str): names = names.replace(',', ' ').split() if isinstance(names, (tuple, list)) and names and isinstance(names[0], str): original_names, names = names, [] last_values = [] for count, name in enumerate(original_names): value = first_enum._generate_next_value_(name, start, count, last_values[:]) last_values.append(value) names.append((name, value)) if names is None: names = () # Here, names is either an iterable of (name, value) or a mapping. for item in names: if isinstance(item, str): member_name, member_value = item, names[item] else: member_name, member_value = item classdict[member_name] = member_value if module is None: try: module = sys._getframemodulename(2) except AttributeError: # Fall back on _getframe if _getframemodulename is missing try: module = sys._getframe(2).f_globals['__name__'] except (AttributeError, ValueError, KeyError): pass if module is None: _make_class_unpicklable(classdict) else: classdict['__module__'] = module if qualname is not None: classdict['__qualname__'] = qualname return metacls.__new__(metacls, class_name, bases, classdict, boundary=boundary) def _convert_(cls, name, module, filter, source=None, *, boundary=None, as_global=False): """ Create a new Enum subclass that replaces a collection of global constants """ # convert all constants from source (or module) that pass filter() to # a new Enum called name, and export the enum and its members back to # module; # also, replace the __reduce_ex__ method so unpickling works in # previous Python versions module_globals = sys.modules[module].__dict__ if source: source = source.__dict__ else: source = module_globals # _value2member_map_ is populated in the same order every time # for a consistent reverse mapping of number to name when there # are multiple names for the same number. members = [ (name, value) for name, value in source.items() if filter(name)] try: # sort by value members.sort(key=lambda t: (t[1], t[0])) except TypeError: # unless some values aren't comparable, in which case sort by name members.sort(key=lambda t: t[0]) body = {t[0]: t[1] for t in members} body['__module__'] = module tmp_cls = type(name, (object, ), body) cls = _simple_enum(etype=cls, boundary=boundary or KEEP)(tmp_cls) if as_global: global_enum(cls) else: sys.modules[cls.__module__].__dict__.update(cls.__members__) module_globals[name] = cls return cls @classmethod def _check_for_existing_members_(mcls, class_name, bases): for chain in bases: for base in chain.__mro__: if isinstance(base, EnumType) and base._member_names_: raise TypeError( "<enum %r> cannot extend %r" % (class_name, base) ) @classmethod def _get_mixins_(mcls, class_name, bases): """ Returns the type for creating enum members, and the first inherited enum class. bases: the tuple of bases that was given to __new__ """ if not bases: return object, Enum # ensure final parent class is an Enum derivative, find any concrete # data type, and check that Enum has no members first_enum = bases[-1] if not isinstance(first_enum, EnumType): raise TypeError("new enumerations should be created as " "`EnumName([mixin_type, ...] [data_type,] enum_type)`") member_type = mcls._find_data_type_(class_name, bases) or object return member_type, first_enum @classmethod def _find_data_repr_(mcls, class_name, bases): for chain in bases: for base in chain.__mro__: if base is object: continue elif isinstance(base, EnumType): # if we hit an Enum, use it's _value_repr_ return base._value_repr_ elif '__repr__' in base.__dict__: # this is our data repr # double-check if a dataclass with a default __repr__ if ( '__dataclass_fields__' in base.__dict__ and '__dataclass_params__' in base.__dict__ and base.__dict__['__dataclass_params__'].repr ): return _dataclass_repr else: return base.__dict__['__repr__'] return None @classmethod def _find_data_type_(mcls, class_name, bases): # a datatype has a __new__ method, or a __dataclass_fields__ attribute |
| You are visitor 01402503 — GeezerVison does not store the pages you look up. Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required. |