instantiating in a class - Python 3

Question

How to use 'self' in python 3 online here, it works in pycharm, but it adds the (self) itself. It's not seeing attack as defined as it's inside the class. it's not transferring to the object somehow. It should just print 'ouch'.

I've also tried def__init__self(): but this online editor python 3 version doesn't seem to recognize the __init__self

class Enemy:
     def attack(self):
          print('ouch')
enemy1 = Enemy
enemy1.attack()

Why no ouch???? :-)

Answer 1

You need to add the argument list (empty in your case) after the class name to properly instantiate it. In many languages this step is referred as calling the constructor.

enemy1 = Enemy()

With this, your code works fine.

Comments

Yup, below is an example:
```
num_nodes = 5
edges = [(0,1), (0,4), (1,2), (1,3), (1,4), (2,3), (3,4)]


#Defining a Graph class to maintain the info for the graph as an adjacency list
class Graph:
    def __init__(self, num_nodes, edges):
        self.num_nodes = num_nodes
        self.edges = edges
        print("Test")

graph = Graph(num_nodes, edges)
```

This should print: "Test"