diff options
Diffstat (limited to 'Lib/enum.py')
| -rw-r--r-- | Lib/enum.py | 37 |
1 files changed, 31 insertions, 6 deletions
diff --git a/Lib/enum.py b/Lib/enum.py index b8787d19b88..e7889a8dc77 100644 --- a/Lib/enum.py +++ b/Lib/enum.py @@ -1,8 +1,14 @@ import sys -from collections import OrderedDict from types import MappingProxyType, DynamicClassAttribute -__all__ = ['Enum', 'IntEnum', 'unique'] +# try _collections first to reduce startup cost +try: + from _collections import OrderedDict +except ImportError: + from collections import OrderedDict + + +__all__ = ['EnumMeta', 'Enum', 'IntEnum', 'unique'] def _is_descriptor(obj): @@ -58,9 +64,11 @@ class _EnumDict(dict): """ if _is_sunder(key): - raise ValueError('_names_ are reserved for future Enum use') + if key not in ('_order_', ): + raise ValueError('_names_ are reserved for future Enum use') elif _is_dunder(key): - pass + if key == '__order__': + key = '_order_' elif key in self._member_names: # descriptor overwriting an enum? raise TypeError('Attempted to reuse key: %r' % key) @@ -100,6 +108,9 @@ class EnumMeta(type): for name in classdict._member_names: del classdict[name] + # adjust the sunders + _order_ = classdict.pop('_order_', None) + # check for illegal enum names (any others?) invalid_names = set(members) & {'mro', } if invalid_names: @@ -204,6 +215,14 @@ class EnumMeta(type): 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) + if _order_ is not None: + if isinstance(_order_, str): + _order_ = _order_.replace(',', ' ').split() + if _order_ != enum_class._member_names_: + raise TypeError('member order does not match _order_') + return enum_class def __bool__(self): @@ -544,8 +563,14 @@ class Enum(metaclass=EnumMeta): source = vars(source) else: source = module_globals - members = {name: value for name, value in source.items() - if filter(name)} + # We use an OrderedDict of sorted source keys so that the + # _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 rather than varying + # between runs due to hash randomization of the module dictionary. + members = OrderedDict((name, source[name]) + for name in sorted(source.keys()) + if filter(name)) cls = cls(name, members, module=module) cls.__reduce_ex__ = _reduce_ex_by_name module_globals.update(cls.__members__) |