Question about __init__ method

#1 First Method
class Triangle(object):
    def area(self, b, h):
        self.b = b
        self.h = h
        return b*h/2
a = Triangle()

a.area(4,8)

I tried to write down the code above using the init method.

#2 Try the second method
class Triangle(object):

    def __init__(self, value_v, value_h):
        b = value_h
        h = value_v

    def area(self,b,h):
        return b*h / 2

a=Triangle()
a.area(4,8)

However, the following error message was received:

 8     def area(self,b,h):
      9         return b*h / 2
---> 10 a=Triangle()
     11 a.area(4,8)

TypeError: __init__() missing 2 required positional arguments: 'value_v' and 'value_h'

.#2 Code

a=Triangle( )

It works well when you get rid of it.

Question 1

Unlike .#1, I wonder why it works well when you get rid of Triangle().

Question 2

class triangle(object): even if you remove the parentheses from class triangle:, it goes the same way. I wonder why you put the parentheses.

I'd appreciate it if you could answer

Have a nice day!

init def python

2022-10-18 09:00

1 Answers

If you use the _init___ method, you must pass the parameter at a=Triangle() to the parameter after self in the __init____ method.
It is ideal to use it as below.

class Triangle(object):
    def __init__(self, b, h):
        self.b = b
        self.h = h

    def area(self):
        return self.b * self.h / 2

a = Triangle(4, 8)
print(a.area())

2022-10-18 09:00

If you have any answers or tips

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