bpo-31801: Enum: add _ignore_ as class option (#5237)
* bpo-31801: Enum: add _ignore_ as class option
_ignore_ is a list, or white-space seperated str, of names that will not
be candidates for members; these names, and _ignore_ itself, are removed
from the final class.
* bpo-31801: Enum: add documentation for _ignore_
* bpo-31801: Enum: remove trailing whitespace
* bpo-31801: Enum: fix bulleted list format
* bpo-31801: add version added for _ignore_
diff --git a/Lib/enum.py b/Lib/enum.py
index fe7cb20..e5fe6f3 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -64,6 +64,7 @@
super().__init__()
self._member_names = []
self._last_values = []
+ self._ignore = []
def __setitem__(self, key, value):
"""Changes anything not dundered or not a descriptor.
@@ -77,17 +78,28 @@
if _is_sunder(key):
if key not in (
'_order_', '_create_pseudo_member_',
- '_generate_next_value_', '_missing_',
+ '_generate_next_value_', '_missing_', '_ignore_',
):
raise ValueError('_names_ are reserved for future Enum use')
if key == '_generate_next_value_':
setattr(self, '_generate_next_value', value)
+ 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('Attempted to reuse key: %r' % key)
+ elif key in self._ignore:
+ pass
elif not _is_descriptor(value):
if key in self:
# enum overwriting a descriptor?
@@ -124,6 +136,12 @@
# 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).
+ #
+ # remove any keys listed in _ignore_
+ classdict.setdefault('_ignore_', []).append('_ignore_')
+ ignore = classdict['_ignore_']
+ for key in ignore:
+ classdict.pop(key, None)
member_type, first_enum = metacls._get_mixins_(bases)
__new__, save_new, use_args = metacls._find_new_(classdict, member_type,
first_enum)