Lists are unhashable in every Python. If you want to use them as keys in a dictionary, you have to use tuples instead. You can probably fix it by doing
dict([ (tuple(map(int, monom)), coeff) for monom, coeff in M[0,0] ]) (though I haven't tried it). Aaron Meurer On Apr 19, 2010, at 1:43 PM, Ben Goodrich wrote: > Hi Mateusz, > > I think I understand but ... > > On Apr 19, 12:13 pm, Mateusz Paprocki <matt...@gmail.com> wrote: >> They look identical, but they're not. As you use F.as_dict(), then in >> both cases c_i are of type Integer. However, keys of _50 and _51 are >> different. In _50 M_i are tuples of Integer instances and in _51 they >> are tuples of ints. When you created a Matrix of FF then FF got sympified >> and all ints were converted to Integers. Poly, however, expects M_i to >> have int exponents. To solve this problem you can replace dict(M[0,0]) >> with: >> >> dict([ (map(int, monom), coeff) for monom, coeff in M[0,0] ]) > > this results in an error > > In [12]: dict([ (map(int, monom), coeff) for monom, coeff in M[0,0] ]) > --------------------------------------------------------------------------- > TypeError Traceback (most recent call > last) > > /tmp/mattpap-sympy-polys-cd30a32/<ipython console> in <module>() > > TypeError: list objects are unhashable > > Maybe you meant something slightly different? Or is it another Python > 2.5 vs 2.6 thing? > > Thanks, > Ben > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sy...@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > 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 sy...@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
