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Source Code for Module pyffi.object_models.any_type

 1  """Defines base class for any type that stores mutable data 
 2  which is readable and writable, and can check for exchangeable 
 3  alternatives. 
 4  """ 
 5   
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44   
45  import pyffi.utils.graph 
46   
47 -class AnyType(pyffi.utils.graph.DetailNode): 
48      """Abstract base class from which all types are derived.""" 
49   
50 -    def read(self, stream): 
51          """Read object from file. 
52   
53          :param stream: The stream to read from. 
54          :type stream: ``file`` 
55          """ 
56          raise NotImplementedError 
57   
58 -    def write(self, stream): 
59          """Write object to file. 
60   
61          :param stream: The stream to write to. 
62          :type stream: ``file`` 
63          """ 
64          raise NotImplementedError 
65   
66 -    def is_interchangeable(self, other): 
67          """Returns ``True`` if objects are interchangeable, that is, 
68          "close" enough to each other so they can be considered equal 
69          for practical purposes. This is useful for instance when comparing 
70          data and trying to remove duplicates. 
71   
72          This default implementation simply checks for object identity. 
73   
74          >>> x = AnyType() 
75          >>> y = AnyType() 
76          >>> x.is_interchangeable(y) 
77          False 
78          >>> x.is_interchangeable(x) 
79          True 
80   
81          :return: ``True`` if objects are close, ``False`` otherwise. 
82          :rtype: ``bool`` 
83          """ 
84          return self is other 
85   
86 -    def __hash__(self): 
87          """AnyType objects are mutable, so raise type error on hash 
88          calculation, as they cannot be safely used as dictionary keys. 
89          """ 
90          raise TypeError("%s objects are unhashable" % self.__class__.__name__) 
91   

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