python/m5/multidict.py

   1 __all__ = [ 'multidict' ]
   2
   3 class multidict(object):
   4     __nodefault = object()
   5     def __init__(self, parent = {}, **kwargs):
   6         self.dict = dict(**kwargs)
   7         self.parent = parent
   8         self.deleted = {}
   9
  10     def __str__(self):
  11         return str(dict(self.items()))
  12
  13     def __repr__(self):
  14         return `dict(self.items())`
  15
  16     def __contains__(self, key):
  17         return self.dict.has_key(key) or self.parent.has_key(key)
  18
  19     def __delitem__(self, key):
  20         try:
  21             del self.dict[key]
  22         except KeyError, e:
  23             if key in self.parent:
  24                 self.deleted[key] = True
  25             else:
  26                 raise KeyError, e
  27
  28     def __setitem__(self, key, value):
  29         self.deleted.pop(key, False)
  30         self.dict[key] = value
  31
  32     def __getitem__(self, key):
  33         try:
  34             return self.dict[key]
  35         except KeyError, e:
  36             if not self.deleted.get(key, False) and key in self.parent:
  37                 return self.parent[key]
  38             else:
  39                 raise KeyError, e
  40
  41     def __len__(self):
  42         return len(self.dict) + len(self.parent)
  43
  44     def next(self):
  45         for key,value in self.dict.items():
  46             yield key,value
  47
  48         if self.parent:
  49             for key,value in self.parent.next():
  50                 if key not in self.dict and key not in self.deleted:
  51                     yield key,value
  52
  53     def has_key(self, key):
  54         return key in self
  55
  56     def iteritems(self):
  57         for item in self.next():
  58             yield item
  59
  60     def items(self):
  61         return [ item for item in self.next() ]
  62
  63     def iterkeys(self):
  64         for key,value in self.next():
  65             yield key
  66
  67     def keys(self):
  68         return [ key for key,value in self.next() ]
  69
  70     def itervalues(self):
  71         for key,value in self.next():
  72             yield value
  73
  74     def values(self):
  75         return [ value for key,value in self.next() ]
  76
  77     def get(self, key, default=__nodefault):
  78         try:
  79             return self[key]
  80         except KeyError, e:
  81             if default != self.__nodefault:
  82                 return default
  83             else:
  84                 raise KeyError, e
  85
  86     def setdefault(self, key, default):
  87         try:
  88             return self[key]
  89         except KeyError:
  90             self.deleted.pop(key, False)
  91             self.dict[key] = default
  92             return default
  93
  94     def _dump(self):
  95         print 'multidict dump'
  96         node = self
  97         while isinstance(node, multidict):
  98             print '    ', node.dict
  99             node = node.parent
 100
 101     def _dumpkey(self, key):
 102         values = []
 103         node = self
 104         while isinstance(node, multidict):
 105             if key in node.dict:
 106                 values.append(node.dict[key])
 107             node = node.parent
 108         print key, values
 109
 110 if __name__ == '__main__':
 111     test1 = multidict()
 112     test2 = multidict(test1)
 113     test3 = multidict(test2)
 114     test4 = multidict(test3)
 115
 116     test1['a'] = 'test1_a'
 117     test1['b'] = 'test1_b'
 118     test1['c'] = 'test1_c'
 119     test1['d'] = 'test1_d'
 120     test1['e'] = 'test1_e'
 121
 122     test2['a'] = 'test2_a'
 123     del test2['b']
 124     test2['c'] = 'test2_c'
 125     del test1['a']
 126
 127     test2.setdefault('f', multidict)
 128
 129     print 'test1>', test1.items()
 130     print 'test2>', test2.items()
 131     #print test1['a']
 132     print test1['b']
 133     print test1['c']
 134     print test1['d']
 135     print test1['e']
 136
 137     print test2['a']
 138     #print test2['b']
 139     print test2['c']
 140     print test2['d']
 141     print test2['e']
 142
 143     for key in test2.iterkeys():
 144         print key
 145
 146     test2.get('g', 'foo')
 147     #test2.get('b')
 148     test2.get('b', 'bar')
 149     test2.setdefault('b', 'blah')
 150     print test1
 151     print test2
 152     print `test2`
 153
 154     print len(test2)
 155
 156     test3['a'] = [ 0, 1, 2, 3 ]
 157
 158     print test4