Python learns to record seven---inheritance, polymorphism, and encapsulation

1. Create a class

Create File test7.py
#! /usr/bin/env python
Class Person:

def setName (self, name):
Self.name = Name
def getName (self):
Return Self.name
def greet (self):
Print "Hello, world! I am%s. " % Self.name

Foo = person ()
Foo.setname (' Yilia ')
Foo.getname ()
Foo.greet ()

2. Characteristics, Functions, methods
Private variable: Just precede its name with a double underline:
Class secretive:

def __inaccessible (self):
Print "Bet you can ' t see me"

def accessible (self):
Print "This secret message is:"
Self.__inaccessible () # Internal Call private method

s = secretive ()
S.accessible ()
S.__inaccessible () #外部调用私有方法

3. Namespaces for classes

>>> class Counter:
... b = 0
... def init (self):
... self.b + = 1
...
>>> NUM1 = Counter ()
>>> Num1.init ()
>>> counter.b
0
>>> Num1.init ()
>>> counter.b
0
>>> num1.b
2
>>> num2 = Counter ()
>>> Num2.init ()
>>> counter.b
0
>>> num2.b
1

4, specify the superclass to write the other class name in parentheses after the class statement can be specified in the superclass, multiple superclass with "," delimited

(1) using Super-class
Class Filter:
def init (self):
self.blocked = []
def filter (self, sequence):
return [x for x in sequence if x not in self.blocked]

Class Spamfilter (Filter):
def init (self):
self.blocked = [' SPAM ']

(2) See if a class is a subclass of another class, using Issubclass
>>> Issubclass (Spamfilter, Filter)
Ture
>>> Issubclass (Filter, Spamfilter)
False

(3) If you want to know the base class of a Class (you), you can use its special properties __bases__
>>> class Counter:
... b = 0
... def init (self):
... self.b + = 1
...

>>> counter.__bases__
()

>>> class AddCounter (Counter):
... def init (self):
... print "This is subclass"
...
>>> Issubclass (AddCounter, Counter)
True
>>> addcounter.__bases__
(<class __main__. Counter at 0x7fcd9b5db328>,)
>>>

5. Interface and Introspection

Python learns to record seven---inheritance, polymorphism, and encapsulation