So I’ve recently dived into OOP, and so far everything is going smooth. Whilst I have no issues per se, there’s an amazing feature which I hope exists, though I cannot find any documentation on said feature.
When assigning attributes to objects, I often find that I have to change attribues that are dependent upon others, say, light and darkness. Here’s an example:
class shade: def __init__(self, light): self.light=light self.darkness=100-light def __str__(self): return (str(self.light) + ',' + str(self.darkness)) shade1=shade(30,70) shade1.light 30 shade1.darkness 70
Now, while that is cool and all, what I would like is the same process to occur, but within the same object if a change in one attribute occurs. If I reset the property of light (oh yeah), I want darkness to incr/decr accordingly. I can do this with a function if it works to change the property of light, returning the new value of light/darkness, but I’d like a way to do this if i change the property of light simply by re-assigning it’s value, w/out the use of functions, Like this:
50 shade1.light 50 shade1.darkness 50shade1.light=
Also, as am new to OOP, if anyone knows some good tutorials, that would also be a massive help.
Thanks in advance.
darkness as a property
class shade: def __init__(self, light): self.light=light def darkness(self): return 100 - self.light def __str__(self): return (str(self.light) + ',' + str(self.darkness))
Properties outwardly appear as attributes, but internally act as function calls. When you say
s.darkness it will call the function you’ve provided for its property. This allows you to only maintain one variable internally.
If you want to be able to modify it by assigning to darkness, add a
setter for the property
class shade: def __init__(self, light): self.light=light def darkness(self): return 100 - self.light def darkness(self, value): self.light = 100 - value
Thereby actually modifying light. If you’ve never seen properties before, I’d recommend throwing in some
print()s to the bodies of the functions so you can see when they are called.
70) s.light 70 s.darkness 30 s.light = 10 s.darkness 90 s.darkness = 20 s.light 80s = shade(