Anatomy of python classes | run this code here -> https://repl.it/CqLt/3

complex.py

def add(self, other):		# overloading + operator
	return self.__class__(self.a + other.a, self.b + other.b)

def sub(self, other):		# overloading - operator
	return self.__class__(self.a - other.a, self.b - other.b)

def constructor(self, a = 0, b = 0):		# to be constructor
	self.a = a
	self.b = b

def repr(self):			# overload output stream
	return '<{0}: {1}+i{2} >'.format(self.__class__.__name__, self.a, self.b)

c = type('Complex', (object,), {		# monkeypatch B-)
		'__add__': add,
		'__sub__': sub,
		'__init__': constructor,
		'__repr__': repr
	})

c1 = c(1, 2)
c2 = c(1, 1)
print(c1, c2)
print(c1+c2)