Is it must to create a __init__ method in a class?

Question

Assigning property by __init__ is quite convinient, but just to check the compulsion of having a __init__ method, i tried this one:
http://www.sololearn.com/app/JUMP_LINK__&&__python__&&__JUMP_LINK/playground/chC0rWvmtmgS/

Answer 1

no it's not necessary

class A(object):
def f():
print 'foo'

a =A()
a.f()

Answer 2

its not a must