| jcgregorio@wpgntai-ubiq72.hot.corp.google.com | ed13252 | 2010-04-19 11:12:52 -0700 | [diff] [blame^] | 1 | """Drop-in replacement for collections.OrderedDict by Raymond Hettinger |
| 2 | |
| 3 | http://code.activestate.com/recipes/576693/ |
| 4 | |
| 5 | """ |
| 6 | from UserDict import DictMixin |
| 7 | |
| 8 | # Modified from original to support Python 2.4, see |
| 9 | # http://code.google.com/p/simplejson/issues/detail?id=53 |
| 10 | try: |
| 11 | all |
| 12 | except NameError: |
| 13 | def all(seq): |
| 14 | for elem in seq: |
| 15 | if not elem: |
| 16 | return False |
| 17 | return True |
| 18 | |
| 19 | class OrderedDict(dict, DictMixin): |
| 20 | |
| 21 | def __init__(self, *args, **kwds): |
| 22 | if len(args) > 1: |
| 23 | raise TypeError('expected at most 1 arguments, got %d' % len(args)) |
| 24 | try: |
| 25 | self.__end |
| 26 | except AttributeError: |
| 27 | self.clear() |
| 28 | self.update(*args, **kwds) |
| 29 | |
| 30 | def clear(self): |
| 31 | self.__end = end = [] |
| 32 | end += [None, end, end] # sentinel node for doubly linked list |
| 33 | self.__map = {} # key --> [key, prev, next] |
| 34 | dict.clear(self) |
| 35 | |
| 36 | def __setitem__(self, key, value): |
| 37 | if key not in self: |
| 38 | end = self.__end |
| 39 | curr = end[1] |
| 40 | curr[2] = end[1] = self.__map[key] = [key, curr, end] |
| 41 | dict.__setitem__(self, key, value) |
| 42 | |
| 43 | def __delitem__(self, key): |
| 44 | dict.__delitem__(self, key) |
| 45 | key, prev, next = self.__map.pop(key) |
| 46 | prev[2] = next |
| 47 | next[1] = prev |
| 48 | |
| 49 | def __iter__(self): |
| 50 | end = self.__end |
| 51 | curr = end[2] |
| 52 | while curr is not end: |
| 53 | yield curr[0] |
| 54 | curr = curr[2] |
| 55 | |
| 56 | def __reversed__(self): |
| 57 | end = self.__end |
| 58 | curr = end[1] |
| 59 | while curr is not end: |
| 60 | yield curr[0] |
| 61 | curr = curr[1] |
| 62 | |
| 63 | def popitem(self, last=True): |
| 64 | if not self: |
| 65 | raise KeyError('dictionary is empty') |
| 66 | # Modified from original to support Python 2.4, see |
| 67 | # http://code.google.com/p/simplejson/issues/detail?id=53 |
| 68 | if last: |
| 69 | key = reversed(self).next() |
| 70 | else: |
| 71 | key = iter(self).next() |
| 72 | value = self.pop(key) |
| 73 | return key, value |
| 74 | |
| 75 | def __reduce__(self): |
| 76 | items = [[k, self[k]] for k in self] |
| 77 | tmp = self.__map, self.__end |
| 78 | del self.__map, self.__end |
| 79 | inst_dict = vars(self).copy() |
| 80 | self.__map, self.__end = tmp |
| 81 | if inst_dict: |
| 82 | return (self.__class__, (items,), inst_dict) |
| 83 | return self.__class__, (items,) |
| 84 | |
| 85 | def keys(self): |
| 86 | return list(self) |
| 87 | |
| 88 | setdefault = DictMixin.setdefault |
| 89 | update = DictMixin.update |
| 90 | pop = DictMixin.pop |
| 91 | values = DictMixin.values |
| 92 | items = DictMixin.items |
| 93 | iterkeys = DictMixin.iterkeys |
| 94 | itervalues = DictMixin.itervalues |
| 95 | iteritems = DictMixin.iteritems |
| 96 | |
| 97 | def __repr__(self): |
| 98 | if not self: |
| 99 | return '%s()' % (self.__class__.__name__,) |
| 100 | return '%s(%r)' % (self.__class__.__name__, self.items()) |
| 101 | |
| 102 | def copy(self): |
| 103 | return self.__class__(self) |
| 104 | |
| 105 | @classmethod |
| 106 | def fromkeys(cls, iterable, value=None): |
| 107 | d = cls() |
| 108 | for key in iterable: |
| 109 | d[key] = value |
| 110 | return d |
| 111 | |
| 112 | def __eq__(self, other): |
| 113 | if isinstance(other, OrderedDict): |
| 114 | return len(self)==len(other) and \ |
| 115 | all(p==q for p, q in zip(self.items(), other.items())) |
| 116 | return dict.__eq__(self, other) |
| 117 | |
| 118 | def __ne__(self, other): |
| 119 | return not self == other |