Error: "illegal target for variable Annotation" using "@Property"

Question

Like pygame does not have a function similar to the library SFML -> View, I am developing a "camera" format to scroll the screen and preserve the positions of objects within the general coordinate within the "world".

As a standard of pygame, use the rectangle.

To facilitate manipulation, I want to change the variables left and top obtained in the get_rect, adding camera offset to these variables.

Following this example by @jsbueno, I’m having a hard time:

I have a class class Sprite(pygame.sprite.Sprite) and inside it I take the rectangle of an image and store self.ret = self.imagem.get_rect(). So I want to return a different amount than self.ret.left every time this variable is accessed.

But in declaring @property and just below def ret.left(self): i get illegal target for variable annotation. What would be the correct sitaxe in this case?

import pygame

class Sprite(pygame.sprite.Sprite):
    def __init__(self, imagem, x, y):
        self.imagem = pygame.image.load('imagem.png')
        self.ret = self.imagem.get_rect()

        @property
        def ret.left(self): # aqui aparece o erro 

Answer 1

As I said in the nomination comment funções/métodos does not allow the use of the character ., so the syntax error. What you can do is with the method decorated with @property return the class instance pygame.Surface.Rect as follows:

import pygame

class Sprite(pygame.sprite.Sprite):

    def __init__(self, imagem, x, y):
        self.imagem = pygame.image.load('imagem.png')
        self._ret = self.imagem.get_rect()

    @property
    def ret(self):
        return self._ret

Allowing then to do self.ret.left, but which we believe has no meaning, since ret is already an instance attribute self.ret.left is already accessible. Unless you plan to implement a setter for this attribute, where it would then be necessary getter. An alternative would be:

import pygame

class Sprite(pygame.sprite.Sprite):

    def __init__(self, imagem, x, y):
        self.imagem = pygame.image.load('imagem.png')
        self.ret = self.imagem.get_rect()

    @property
    def ret_left(self):
        return self.ret.left

    @property
    def ret_right(self):
        return self.ret.right