class Image:
    def __init__(self, path: str):
        self.path: str = path
 
 
class Window:
    image: Image    # instance variable without default
 
    def __init__(self):
        self.fish: str = "123"
 
    def build(self, path):
        self.image = Image(path)
 
 
window1 = Window()
window1.build('path1')
 
window2 = Window()
window2.build('path2')
 
print(window1.image.path)
print(window2.image.path)
print(window1.image.path)
 
# Only downside I can see: two errors when attempt to use as a class variable
# print(Window.image)     # not flagged by PyCharm
# print(Window.fish)      # flagged by PyCharm
# Not a big problem for me since I don't often use Class Variables and maybe ClassVar will be supported in future
 

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