is there any wrong

Question

class first:
def __init__(self,color,number):
self.color=color
self.num=number
def __sub__(self, other):
return "\n".join([self.color,other.color])

obj=first("hello",24)
var=first("world",12)
print(obj.color-var.color)

Answer 1

class first:
def __init__(self,color,number):
self.color=color
self.num=number
def __sub__(self, other):
return "\n".join([self.color,other.color])

obj=first("hello",24)
var=first("world",12)
print(obj-var)

__sub__ is the magic method for subtraction between two objects, not two attributes.

Answer 2

Agreed with Russ . __sub__ or any other magic method work on objects and not on their properties.

So at the end, instead of print(obj.color - var.color) you should have written print(obj - color).