Save some people. Friends lack sufficient knowledge to try to solve this problem alone.
I have these 3 classes below: Historical <https://github.com/CoutinhoElias/pesquisasatisfacao/blob/master/pesquisasatisfacao/financeiro/models.py#L15-L43>, Account <https://github.com/CoutinhoElias/pesquisasatisfacao/blob/master/pesquisasatisfacao/financeiro/models.py#L46-L72>, Payment <https://github.com/CoutinhoElias/pesquisasatisfacao/blob/master/pesquisasatisfacao/financeiro/models.py#L75-L85> In the admin I can list in the History the added values of Account and Payment as well so I will search in the respective models, however I think it is interesting to also present a column with the remaining value, that is, Account - Payment (Clustered value of accounts subtracted from the payment) . I thought it would be easy to do but it returns me the following error: unsupported operand type (s) for -: 'NoneType' and 'NoneType' I know it means the message but I do not know how to solve it. Has anyone ever experienced this? Can you help me? -- You received this message because you are subscribed to the Google Groups "Django users" 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 https://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/d3190fd9-0fdf-4e1d-9f3d-6a0120662b3e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
