python 中exception，class 学习
instroduction:
Object2 = Object1 ( like java)
if Object1 is class object , then copy by reference;
if Object1 is basic type, then copy by value
1. exception
主要结构：
try:
exception ValueError:
exception ZeroDivisionError:
exception NameError:
exception TypeError:
exception:
finally:
2. custom exception
class Error(Exception):
pass
def MyError(Error):
def __init__(self,value):
print value
self.value = value
def __str__(self):
return repr(self.value)
3. class
class Bird:
number = 0
def __init__(self,name):
self.name = name
print ‘Initializing %s‘ % self.name
def __del__(self):
print ‘del‘,self.number
def fly(self):
print ‘fly %d‘ % self.number
def add(self):
self.number = self.number + 1
def sub(self):
self.number = self.number - 1
class Sparrow(Bird):
def __init__(self,name,alias):
Bird.__init__(self,name)
self.alias = alias
print ‘alias is %s ‘ % self.alias
def fly(self):
print ‘Sparrow fly %s‘ % self.alias
description:
constructor: __init__
destructor:__del__
static data: number
4. file input/output
cPickle or pickle: store the object consistently