python面向对象

kution

------class--------
#!/usr/bin/python
# Filename: simplestclass.py
class Person:
pass # An empty block
p = Person()
print p
$ python simplestclass.py
<__main__.Person instance at 0xf6fcb18c>
------------
#!/usr/bin/python
# Filename: method.py
class Person:
def sayHi(self):
print 'Hello, how are you?'
p = Person()
p.sayHi()
# This short example can also be written as Person().sayHi()
$ python method.py
Hello, how are you?
-------__init__----------是不是可以称为构造方法
#!/usr/bin/python
# Filename: class_init.py
class Person:
def __init__(self, name):
self.name = name
def sayHi(self):
print 'Hello, my name is', self.name
p = Person('Swaroop')
p.sayHi()
# This short example can also be written as Person('Swaroop').sayHi()
$ python class_init.py
Hello, my name is Swaroop
--------
#!/usr/bin/python
# Filename: objvar.py
class Person:
'''Represents a person.'''
population = 0
def __init__(self, name):
'''Initializes the person's data.'''
self.name = name
print '(Initializing %s)' % self.name
# When this person is created, he/she
# adds to the population
Person.population += 1
def __del__(self):
'''I am dying.'''
print '%s says bye.' % self.name
Person.population -= 1
if Person.population == 0:
print 'I am the last one.'
else:
print 'There are still %d people left.' % Person.population
def sayHi(self):
'''Greeting by the person.
Really, that's all it does.'''
print 'Hi, my name is %s.' % self.name
def howMany(self):
'''Prints the current population.'''
if Person.population == 1:
print 'I am the only person here.'
else:
print 'We have %d persons here.' % Person.population
swaroop = Person('Swaroop')
swaroop.sayHi()
swaroop.howMany()
kalam = Person('Abdul Kalam')
kalam.sayHi()
kalam.howMany()
swaroop.sayHi()
swaroop.howMany()
$ python objvar.py
(Initializing Swaroop)
Hi, my name is Swaroop.
I am the only person here.
(Initializing Abdul Kalam)
Hi, my name is Abdul Kalam.
We have 2 persons here.
Hi, my name is Swaroop.
We have 2 persons here.
Abdul Kalam says bye.
There are still 1 people left.
Swaroop says bye.
I am the last one.
当对象不再被使用时，__del__方法运行，但是很难保证这个方法究竟在 什么时候 运行。如果你想要指明它的运行，你就得使用del语句，就如同我们在以前的例子中使用的那样
------------