I have two questions. 

1 - How user adds values on a dictionary? All exemples about dict's that I seen, they are already predefined by the programmer.

2 - I wrote this class

```
class Imovel:                                       
    tamanho = 0                                     
    cor = ''

    def __init__(self, tamanho, cor):               
        self.tamanho = tamanho
        self.cor = cor

    def verificarDisponibilidade(self, situacao):   
        self.situacao = situacao
        if(situacao == True):
            print 'Imovel disponivel'
        else:
            print 'Imovel indisponivel'

```

When I call verificarDisponibilidade() and pass True as parameter, I expect "*Imovel disponivel*" but I got: 

```
Imovel disponivel
None

```

I wonder what that "None" is returned.

Thanks all, and sorry for bad english.