If you google around you can find a frozendict class that is immutable and hashable.
Alternatively there is also a SymPy Dict class. On Thu, Apr 26, 2012 at 4:04 PM, [email protected] < [email protected]> wrote: > There is an easy way to check for yourself that the dict build-in does > not have a hash method: > > In [1]: d = {1:1} > In [2]: hash(d) > TypeError: unhashable type: 'dict' > > Hashes are not defined on mutable objects because the hash of an > object should not change. Thanks to this quality hashes can be used > for cashing. > > Cashing and hashes are an important part of the core, this is why for > the moment if you implement something in sympy it should be immutable. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
