Why is __str__ method not taking 2 params here.

Question

I'm trying out the juicer program in python core. I want to print the output through the __str__method.
This is my code:
class Juice:
def __init__(self, name, capacity):
self.name = name
self.capacity = capacity

def __add__(self, other):
result = self.capacity + other.capacity
return result

def __str__(self,other):
return (self.name + '&' + other.name + ' ('+str(result)+'L)')

a = Juice('Orange', 1.5)
b = Juice('Apple', 2.0)

result = a + b
print(result)

Error: The special method __str__ takes 0 params(s) , 1 was given.

Can someone tell me why the __str__method is showing an error. If I don't mention 2nd argument(other) in str method, there is no error but my output would only be "3.5L" without the names. Also, I want to try printing the result through the str method. How do I do that?

Required Output:
Orange&Apple 3.5L

Answer 1

The __str__ magic method only has one argument and takes 0 parameters.

Think of__str__ to invoke when you call the class inside a print function. The only argument is self which is passed automatically by the class.

Answer 2

Kavya You should put all your desired output code to __add__ without using __str__ at all.