Python重载学习手记
今天学习了一下Python的操作符重载，总结了几点比较神奇的东东：
------------------------------------------------------------------------------------------------------------
关于iter：
Technically, iteration contexts work by calling the iter built-in function to try to
find an _ _iter_ _ method, which is expected to return an iterator object. If it’s
provided,Python then repeatedly calls this iterator object’s next method to produce
items until a StopIteration exception is raised. If no such _ _iter_ _ method is found,
Python falls back on the _ _getitem_ _ scheme, and repeatedly indexes by offsets as
before, until an IndexError exception is raised.
所以为了使用iter，我们必须重载__iter__，然后再定义一个next方法，例子如下：
class Squares:
def _ _init_ _(self, start, stop): # Save state when created
self.value = start - 1
self.stop = stop
def _ _iter_ _(self): # Get iterator object on iter( )
return self
def next(self): # Return a square on each iteration
if self.value == self.stop:
raise StopIteration
self.value += 1
return self.value ** 2
------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------
利用__setattr__的时候，自己赋值不可以使用self.name = value，因为这个语句也是用了__setattr__
，这样重复使用，出错。要使用self.__dict__['name'] = value
------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------
利用__getattr__建立“私有”成员变量：
利用重载的__setattr__在每次取之前判断一下私有成员名字当中有没有，来实现私有，代码如下（取自
Learning Python）
class PrivateExc(Exception): pass
class Privacy:
&nb
相关文档：
使用python.vim使python代码高亮
http://www.vim.org/scripts/script.php?script_id=790
使用
Pydiction插件使vim增加tab代码提示功能
http://www.vim.org/scripts/script.php?script_id=850
具体安装方法可以参照帮助或者README，因为版本变化会导致安装方法上产生差异
编辑~/.vimrc文件增加下面选项
set nu 增加行 ......
import sys, pygame, time
size = width, height = 700,700
fontColor = (0,0,255)
class walk:
'''This is a game about war.
Just like war 3.'''
def __init__(self):
'''Init the screen.
Get param and init the screen'''
#print ('this is init funnction') ......
while 的用法：
while 后面跟条件表达式，(:)后面跟语句块，你可以在这段语句块里修改条件表达式的某些变量，当条件表达式 为假的时候退出循环。例如：
flag = 5
while flag > 0:
#这里是你的代码
flag -= 1
#if flag == 3: break
#if flag == 3: continue
print flag
当然你也可以在适� ......
1. 第二章 语法及代码约定
&nb ......
