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Son-Hai Nguyen2,481 Points
What if I say ```return self + other``` in add method?
What if I say like this for the add method?
def __add__(self, other): return self + other
I tried to run it and python gave me an error
RecursionError: maximum recursion depth exceeded while calling a Python object but I dont know what that is and I dont know why.
Steven Parker216,810 Points
When you refer to "self" directly, you're asking the system to perform an operation implicitly using the "
__add__" method of the class, which is what you are defining here. And when a method calls itself, this is called "recursion".
Since each time the method starts, it causes the system to call itself again, this creates a loop that never ends. Eventually (but not long in human time) the system reaches an internal limit and gives you that error.
So it's necessary to perform the conversion explicitly before the math is performed. Note that this syntax will work for "
__radd__", since it calls "
__add__" and not itself (so no recursion).