python学习1 使用类

#使用类
class CPerson:
#类变量好比C++中的静态成员变量
population = 0

def SayHi(self):
print('Hello World')
def HowMany(self):
if CPerson.population == 1:
print('I am the only person here.')
else:
print(('We have %d persons here.') % CPerson.population)

#类中有很方法的名字有特殊的意义
#__init__好比C++中的构造函数
def __init__(self, name):
self.name = name
print(('Initializing %s') % self.name)
CPerson.population += 1

#__del__好比C++中的析构函数
def __del__(self):
CPerson.population -= 1
if CPerson.population == 0:
print('I am the last one.')
else:
print(('There are still %d people left.') % CPerson.population)

p = CPerson('123456')
p.SayHi()
p.HowMany()
p0 = CPerson('987654321')
p0.SayHi()
p0.HowMany()
p.SayHi()
p.HowMany()
print('------------------------------------------')
#使用继承，多态现象
class SchoolMember:
def __init__(self, name ,age):
self.name = name
self.age = age
print(('Initialized SchoolMember:%s') % self.name)
def Tell(self):
print(('Name:%s, Age:%d') % (self.name, self.age))
class Teacher(SchoolMember):
def __init__(self, name, age, salary):
SchoolMember.__init__(self, name, age)
self.salary = salary
print(('Initialized Teacher:%s') % self.name)
def Tell(self):
SchoolMember.Tell(self)
print(('Salary:%d') % self.salary)
class Student(SchoolMember):
def __init__(self, name, age, marks):
SchoolMember.__init__(self, name, age)
self.marks = marks
print(('Initalized Student:%s') % self.name)
def Tell(self):
SchoolMember.Tell(self)
print(('Marks:%d') % self.marks)
t = Teacher('liyong', 30, 30000)
s = Student('swap', 22, 75)
members = [t, s]
for member in members:
print('######