I don't understand your reasoning for needing multiple objects with the same name.
If these objects are supposed to be different, they should be made so by including all the identifying information in .args (or if that doesn't make sense, by overriding __eq__ and _hashable_content). By the way, unrelated question: if position must be 1, 2, or 3, why does it have to be a string? Aaron Meurer On Thu, Jul 25, 2013 at 10:17 AM, Prasoon Shukla <[email protected]> wrote: > I have subclassed Symbol, like so: > > class BaseScalar(Symbol): > """ > BaseScalar instances are used to express coordinate variables for field. > Not to be instantiated by the user. > """ > def __new__(cls, name, coord_sys, position, **assumptions): > if (position not in ['1', '2', '3'] > and not isinstance(coord_sys, CoordSysRect)): > raise ValueError("Position of scalar not specified. \ > See `position` in docstring of `BaseScalar`") > if name is None: > name = 'Dummy_' + str(Dummy._count) > obj = Symbol.__new__(cls, name, **assumptions) > obj.coord_sys = coord_sys > return obj > > The problem is this: > An instance of this class is created with name 'x' (say). Fine. Everything > works as it should. Then, another instance of this class is created - again > with the name 'x'. The returned object is actually the same 'x' which was > made before. This is happening because __new__ of Symbol is cached - when > the new object is created, it returns the cached object from before. > > What can I do for to generate a new instance of the class instead of > returning the already created object? > > > P.S.: If you are wondering why I am creating the objects with the same name, > it is because the objects are instantiated within another object. So, it's > perfectly alright. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > For more options, visit https://groups.google.com/groups/opt_out. > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
