Function definition in Python

Question

Hi,

I am new to Python. I was trying to define and run a simple function in a class.

Can anybody please tell me what's wrong in my code:

class A :
    def m1(name,age,address) :
     print('Name -->',name)
     print('Age -->',age)
     print('Address -->',address)


>>> a = A()
>>> a.m1('X',12,'XXXX')
Traceback (most recent call last):
  File "<pyshell#22>", line 1, in <module>
    a.m1('X',12,'XXXX')

I am getting below error
TypeError: m1() takes exactly 3 positional arguments (4 given)

Answer 1

By convention, methods in a class instance receive an object reference as the 1st argument, named self.

>>> class A:
...     def m1(self,name,age,address):
...      print('Name -->',name)
...      print('Age -->',age)
...      print('Address -->',address)
...      
>>> a=A()
>>> a.m1('X',12,'XXXX')
('Name -->', 'X')
('Age -->', 12)
('Address -->', 'XXXX')
>>>

Answer 2

Instance methods take instance as first argument:

class A :
    def m1(self, name,age,address) :
        print('Name -->',name)
        print('Age -->',age)
        print('Address -->',address)

You can also use @staticmethod decorator to create static function:

class A :
    @staticmethod
    def m1(name,age,address) :
        print('Name -->',name)
        print('Age -->',age)
        print('Address -->',address)

Answer 3

The first parameter is always the object itself.

class A :
    def m1(self, name,age,address) :
        print('Name -->',name)
        print('Age -->',age)
        print('Address -->',address)