Python Class

'''
Created on 2011-4-30

@author: xuqiang
'''

class Student:
    # attribute 
    i = 12345;
    
    # member function
    def func(self):
        print('in class member function : func');
    
    # init
    def __init__(self):
        print("in __init__ function");
        
        
# class instance
stu = Student();
stu.func();

class Complex :
    # init 
    def __init__(self, real, img):
        self.real = real;
        self.img = img;
    
    
    # operator
    def add(self, other):
        return Complex(self.real + other.real, 
                       self.img + other.img);

c1 = Complex(1, 1);
c2 = Complex(1, 1);
c3 = c1.add(c2);
print(c3.img);

# empty class object
class Employee :
    pass

class MyClass:
    """  a simple class example """
    i = 123456;
    
    def f(self):
        return 'hello world';


c = MyClass();
print(c.f());


class Base:
    """  base class """
    def __init__(self):
        print("in base init.");
    
    def override_func(self):
        print("in base : overrride_func");
    
class Sub(Base):
    def __init__(self):
        print("in sub init");

    def override_func(self):
        print("in sub : override_func");

s = Sub();
s.override_func();

if isinstance(s, Sub):
    print("s is an instance of class Sub");

if issubclass(Sub, Base):
    print("Sub is a sub class of class Base");