property getitem setitem

>>> class Foo(object):
    def __init__(self,name):
        self._name = name
    @property
    def get_name(self):
        return self._name

    
>>> f1=Foo(‘yuyang‘)
>>> f1.get_name
‘yuyang‘
>>> f1.get_name = ‘dfd‘
Traceback (most recent call last):
  File "<pyshell#10>", line 1, in <module>
    f1.get_name = ‘dfd‘
AttributeError: can‘t set attribute

>>> class Foo(object):
    def __init__(self,name):
        self._name = name
    @property
    def get_name(self):
        return self._name
    @get_name.setter
    def get_name(self,value):
        self._name = value

        
>>> f2=Foo(‘yuyagng‘)
>>> f2.get_name
‘yuyagng‘
>>> f2.get_name = ‘alex‘
>>> f2.get_name
‘alex‘

>>> class Foo(object):
    def __init__(self,name):
        self._name = name
    def get_name(self):
        return self._name
    def set_name(self,value):
        self._name = value
    property(get_name,set_name)

    
>>> f3 = Foo(‘dsadsa‘)
>>> f3.get_name
<bound method Foo.get_name of <__main__.Foo object at 0x0000000002F13EF0>>
>>> f3.get_name()
‘dsadsa‘
>>> f3.set_name(‘wupeiqi‘)
>>> f3.get_name()
‘wupeiqi‘
>>> class Foo(object):
    def __init__(self,name):
        self._name = name
    def get_name(self):
        return self._name
    def set_name(self,value):
        self._name = value
    name = property(get_name,set_name)

    
>>> f3 = Foo(‘dsadsa‘)
>>> f3.get_name()
‘dsadsa‘
>>> f3.name = ‘laoda‘
>>> f3.get_name()
‘laoda‘

>>> class Mycalss(object):
    d={‘a‘:1,‘b‘:2,‘c‘:3}
    def __getitem__(self,value):
        return self.d[value]
    def __setitem__(self,key,value):
        self.d[key] = value

        
>>> myclass = Myclass()
Traceback (most recent call last):
  File "<pyshell#23>", line 1, in <module>
    myclass = Myclass()
NameError: name ‘Myclass‘ is not defined
>>> myclass = Mycalss()
>>> myclass[‘a‘]
1
>>> myclass[‘b‘]
2
>>> myclass[‘f‘]=4
>>> myclass[‘f‘]
4
>>> myclass[‘a‘]=‘aaaa‘
>>> myclass[‘a‘]
‘aaaa‘

import base64


>>> a= ‘asdasdfas‘
>>> a2 =a.encode(‘utf-8‘)
>>> a64 = base64.b64encode(a2)
>>> a2
b‘asdasdfas‘
>>> a64
b‘YXNkYXNkZmFz‘
>>> base64.b64encode(a64)
b‘WVhOa1lYTmtabUZ6‘
>>> a64
b‘YXNkYXNkZmFz‘
>>> base64.b64decode(a64)
b‘asdasdfas‘
>>> a64.decode(‘utf-8‘)
‘YXNkYXNkZmFz‘
>>> a64_de = base64.b64decode(a64)
>>> a64_de
b‘asdasdfas‘