Set static attributes...maybe.

[Beppe]

Il giorno lunedì 18 agosto 2014 19:13:08 UTC+2, Chris Kaynor ha scritto:
> On Mon, Aug 18, 2014 at 10:00 AM, Beppe <giuseppe... at gmail.com> wrote:
> 
> 
> hi to everybody,
> 
> in the following scrip I try to call the function read_parameters () but returns me that wants two arguments!?!?!
> 
> My intent is to have in the class, Engine (), some static attributes that can be used by  other instances without to redefine this every time.
> 
> These matters could be for example a path or a connection to a database.
> 
> suggestions?
> 
> 
> 
> regards
> 
> beppe
> 
> 
> 
> class Master(object):
> 
>     def __init__(self,):
> 
>         pass
> 
> 
> 
> class Engine(Master):
> 
>     dict_parameters = {}
> 
>     def __init__(self,):
> 
>         super(Engine, self).__init__()
> 
> 
> 
>     @staticmethod
> 
>     def read_parameters(self,path):
> 
> 
> 
>         self.dict_parameters = {1:"a",2:"b"}
> 
> 
> 
> What you probably want here, based on your description is (untested):
> @classmethod
> def read_parameters(cls, path): # Note, the name is "cls". This is not required, but is convention, similar to "self".
> 
> 
>     cls.dict_parameters = {1:"a",2:"b"}
> 
> 
> @staticmethod creates a method that does not receive any special parameter, so the signature would be "def read_parameters(path)".
> 
> 
> 
> 
> 
> Note that, personally, I would name the method "parse_parameters" to make it clearer what it does.
>  
> 
> 
> 
> 
>     def check_parameters(self):
> 
>         self.read_parameters("hello_world")
Perfet,

class Master(object):
    def __init__(self,):
        pass
          
class Engine(Master):
    
    def __init__(self,):
        super(Engine, self).__init__()

    @classmethod
    def parse_parameters(cls, path):
        cls.dict_parameters = {1:"a",2:"b"}

    def check_parameters(self):
        self.parse_parameters("hello_world")
        
    def __str__(self):
        return "dict_parameters: %s" % self.dict_parameters         
               

foo = Engine()
foo.check_parameters()
bar = Engine()
foobar = Engine()


print foo
print bar
print foobar

IDLE 2.6.6      ==== No Subprocess ====
>>> 
dict_parameters: {1: 'a', 2: 'b'}
dict_parameters: {1: 'a', 2: 'b'}
dict_parameters: {1: 'a', 2: 'b'}

thanks a lot Chris