ordered_dict.py 2.9 KB

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  1. """Drop-in replacement for collections.OrderedDict by Raymond Hettinger
  2. http://code.activestate.com/recipes/576693/
  3. """
  4. from UserDict import DictMixin
  5. class OrderedDict(dict, DictMixin):
  6. def __init__(self, *args, **kwds):
  7. if len(args) > 1:
  8. raise TypeError('expected at most 1 arguments, got %d' % len(args))
  9. try:
  10. self.__end
  11. except AttributeError:
  12. self.clear()
  13. self.update(*args, **kwds)
  14. def clear(self):
  15. self.__end = end = []
  16. end += [None, end, end] # sentinel node for doubly linked list
  17. self.__map = {} # key --> [key, prev, next]
  18. dict.clear(self)
  19. def __setitem__(self, key, value):
  20. if key not in self:
  21. end = self.__end
  22. curr = end[1]
  23. curr[2] = end[1] = self.__map[key] = [key, curr, end]
  24. dict.__setitem__(self, key, value)
  25. def __delitem__(self, key):
  26. dict.__delitem__(self, key)
  27. key, prev, next = self.__map.pop(key)
  28. prev[2] = next
  29. next[1] = prev
  30. def __iter__(self):
  31. end = self.__end
  32. curr = end[2]
  33. while curr is not end:
  34. yield curr[0]
  35. curr = curr[2]
  36. def __reversed__(self):
  37. end = self.__end
  38. curr = end[1]
  39. while curr is not end:
  40. yield curr[0]
  41. curr = curr[1]
  42. def popitem(self, last=True):
  43. if not self:
  44. raise KeyError('dictionary is empty')
  45. key = reversed(self).next() if last else iter(self).next()
  46. value = self.pop(key)
  47. return key, value
  48. def __reduce__(self):
  49. items = [[k, self[k]] for k in self]
  50. tmp = self.__map, self.__end
  51. del self.__map, self.__end
  52. inst_dict = vars(self).copy()
  53. self.__map, self.__end = tmp
  54. if inst_dict:
  55. return (self.__class__, (items,), inst_dict)
  56. return self.__class__, (items,)
  57. def keys(self):
  58. return list(self)
  59. setdefault = DictMixin.setdefault
  60. update = DictMixin.update
  61. pop = DictMixin.pop
  62. values = DictMixin.values
  63. items = DictMixin.items
  64. iterkeys = DictMixin.iterkeys
  65. itervalues = DictMixin.itervalues
  66. iteritems = DictMixin.iteritems
  67. def __repr__(self):
  68. if not self:
  69. return '%s()' % (self.__class__.__name__,)
  70. return '%s(%r)' % (self.__class__.__name__, self.items())
  71. def copy(self):
  72. return self.__class__(self)
  73. @classmethod
  74. def fromkeys(cls, iterable, value=None):
  75. d = cls()
  76. for key in iterable:
  77. d[key] = value
  78. return d
  79. def __eq__(self, other):
  80. if isinstance(other, OrderedDict):
  81. return len(self)==len(other) and \
  82. all(p==q for p, q in zip(self.items(), other.items()))
  83. return dict.__eq__(self, other)
  84. def __ne__(self, other):
  85. return not self == other