_collections.py (743B)
- import collections
- # from jaraco.collections 3.3
- class FreezableDefaultDict(collections.defaultdict):
- """
- Often it is desirable to prevent the mutation of
- a default dict after its initial construction, such
- as to prevent mutation during iteration.
- >>> dd = FreezableDefaultDict(list)
- >>> dd[0].append('1')
- >>> dd.freeze()
- >>> dd[1]
- []
- >>> len(dd)
- 1
- """
- def __missing__(self, key):
- return getattr(self, '_frozen', super().__missing__)(key)
- def freeze(self):
- self._frozen = lambda key: self.default_factory()
- class Pair(collections.namedtuple('Pair', 'name value')):
- @classmethod
- def parse(cls, text):
- return cls(*map(str.strip, text.split("=", 1)))