python学习笔记——字典操作

修改

a={'add':"shanghao","name":"zhangdong"}
a['name']='zhangsan'

添加

a={'add':"shanghao","name":"zhangdong"}
a['

　删除

a={"}
del a['age']
print a
a={'add':"shanghao","name":"zhangdong"}

>>> a={"diqu":"shanghai","name":"xiaolin"}
>>> a.clear()
>>> a
{}

删除了但还是存在

len()测试长度

>>> aname={'name':'xiaowang','sex':'nan','diqu':'shanghai'}
>>> len(aname)
3
>>>

keys()

>>> aname={'name':'xiaowang','sex':'nan','diqu':'shanghai'}
>>> aname.keys()
['diqu', 'name', 'sex']

values()

>>> aname={'name':'xiaowang','sex':'nan','diqu':'shanghai'}
>>> aname.values()
['shanghai', 'xiaowang', 'nan']

has_key(key)如果在字典里返回ture否则返回fales

>>> aname={'name':'xiaowang','sex':'nan','diqu':'shanghai'}
>>> aname.has_key('name')
True
>>> aname.has_key('age')
False