Python: How modificate a value of all the objects from a class ?

[renardjap]

Hello,

I have a question about python's classes. Is it possible to modificate a value of all the objects from a class ???

Exemple

Code: Select all

class Perso:
    def __init__(self, name, age):
        self.name = name
        self.age = age
        
    def older(self):
        self.age += 1


patrick = Perso("Patrick", 20)
michel = Perso("Michel", 25)
#and more guys

Perso.older() # I want the value age increment for all the characters who belongs to the class Perso... but doesn't work... 

print(patrick.age)
print(michel.age)

I want to create a function to let increment the self.age value of all the characters of the class Perso.

Is it possible ?
How can I do ?

Thanks for your answers

[MaydohMaydoh]

If it was me, I would stick all the new instances into a dictionary and run through them all in a for loop.

Code: Select all

perso_dict = {
    "patrick" : Perso("Patrick", 20),
    "michel" : Perso("Michel, 25)
    }
    
for k in perso_dict:
    perso_dict[k].older()

[hell_oh_world]

Hello,

I have a question about python's classes. Is it possible to modificate a value of all the objects from a class ???

Exemple

Code: Select all

class Perso:
    def __init__(self, name, age):
        self.name = name
        self.age = age
        
    def older(self):
        self.age += 1


patrick = Perso("Patrick", 20)
michel = Perso("Michel", 25)
#and more guys

Perso.older() # I want the value age increment for all the characters who belongs to the class Perso... but doesn't work... 

print(patrick.age)
print(michel.age)

I want to create a function to let increment the self.age value of all the characters of the class Perso.

Is it possible ?
How can I do ?

Thanks for your answers

Code: Select all

class Perso:

    old = 0 # you declare class variables outside the methods.

    def __init__(self, name, age):
        self.name = name
        self._age = age + self.old
        
    @classmethod
    def older(cls, value=1):
        cls.old += value
       
patrick = Perso("Patrick", 20)
michel = Perso("Michel", 25)

# print(patrick.age)
# >>> 20
# patrick.older() # or michel.order() or Perso.older() or patrick.old += 1 ....
# print(patrick.age)
# >>> 21
# print(michel.age)
# >>> 26

You use class attributes for that. They are shared across all instances of a class. object attributes are those variables that you declared inside the constructor / init method. Then you can make a classmethod or a normal method whichever you prefer that will increment the class attribute. In this case, a classmethod makes more sense. You can also directly increment it by accessing the class attribute directly.

[drKlauz]

I would use something like

Code: Select all

default global_age=0

init python:
  class Perso(object):
    def __init__(self,name,age):
      self.name=name
      self._age=age
    @property
    def age(self):
      return global_age+self._age
    @age.setter
    def age(self,age):
      self._age=age

label new_year:
  $global_age+=1
  "Happy New Year!"
  return

Having global dict of all characters also good idea, tho this may depend on how you structure your game.
Class attributes shouldn't be used for such things, as RenPy do not save them.

[renardjap]

Thank you very much all of you for your answers !

@ MaydohMaydoh: I have the same idée but I search something more Object Oriented Programming

@ hell_oh_world: It 's very interesting to use this @classmethod

@ drKlauz: It's a problem if renpy doesn't save it ! I need to keep it in the memory