[Resolved] Attribute accessors in Python?

[Fantasist]

Most of you must be familiar with how we can define setting and getting attributes in a class:

class Foo

   def initialize(val=0)
      @var = val
   end

   def var
      return @var
   end

   def var=(val)
      val = [[0, val].max, 100].min # Binding the value
      @var = val
   end

end

I would like to do the same in a Python class. What is the syntax for defining the "var=(val)" method in Python?

[fugibo]

Tried Google yet?

[Blizzard]

In Python everything is public.

class Foo():

    def __init__(self):
        self.bar = 1

foobar = Foo()
print foobar.bar # will print 1
foobar.bar = 2
print foobar.bar # will print 2

[Fantasist]

Tried Google yet?

Yes, but I didn't know what to search for. I tried some stuff but didn't find what I need. Though, I stumbled upon the implementation in some module on the internet.

In Python everything is public.

class Foo():

    def __init__(self):
        self.bar = 1

foobar = Foo()
print foobar.bar # will print 1
foobar.bar = 2
print foobar.bar # will print 2

Yes, but I want to have more control over setting and getting attributes.

Anyway, I kind of figured it out. The key is the __getattr__ method. It gets called when a called attribute is not found. I guess this is resolved until furthur notice. Thanks guys

[Blizzard]

class Foo():

    def __init__(self):
        self.bar = 1

    def getBar(self):
        return self.bar

    def setBar(self, newBar):
        self.bar = newBar

    Bar = property(getBar, setBar)

foobar = Foo()
print foobar.Bar # will print 1
foobar.Bar = 2
print foobar.Bar # will print 2

getBar and setBar will still be visible as well as bar outside of foo.

[fugibo]

...he means like this, I believe:

class Foo
  def initialize
    @bar = nil
    @state = true
  end
  
  def bar=(nbar)
    @bar = nbar.size > 2 ? [nbar.first, nbar.last] : nbar
  end

  def bar
    @state = ! @state
    return @state ? @bar : [nil, nil]
  end
end

Sucky example, but it shows the complexity that he might need, and it's fun
But he got, so it's all good. *goes off the learn some python*

[Blizzard]

That's what I did. He can use .Bar (with capital B, yes) to assign or get the variable over the set and get method. i.e.

class Foo():

    def __init__(self):
        self.bar = 1

    def getBar(self):
        return self.bar + 1

    def setBar(self, newBar):
        self.bar = newBar

    Bar = property(getBar, setBar)

foobar = Foo()
print foobar.Bar # will print 1
foobar.Bar = foobar.Bar
print foobar.Bar # will print 2

It pretty much works like C#'s properties. Except that you can still see all the other stuff. >.<

[fugibo]

Ooh. Python is fancy then. Sorry Blizz

[Blizzard]

Code: C#

class Foo
{
    private int bar;
    public Foo()
    {
        this.bar = 1;
    }
    public int Bar
    {
        get { return this.bar; }
        set { this.bar = value; }
    }
}

xD

[fugibo]

I wonder how Obj-C does that stuff. It gain do a ton of crap from what little I've seen, and it's really Ruby-like, but the syntax is god-awful.

[Fantasist]

Bar = property(getBar, setBar)

lol, I did even more reading and I came across properties just an hour ago. Gotta say, I'm starting to like Python.