基本语法:

dict = {'ob1':'computer', 'ob2':'mouse', 'ob3':'printer'}

技巧:

字典中包含列表:dict={'yangrong':['23','IT'],"xiaohei":['22','dota']}

字典中包含字典:dict={'yangrong':{"age":"23","job":"IT"},"xiaohei":{"'age':'22','job':'dota'"}}

 

可用命令:

root@yangrong:~# cd /python
root@yangrong:/python# python
Python 2.7.5+ (default, Sep 19 2013,13:48:49)
[GCC 4.8.1] on linux2
Type "help","copyright", "credits" or "license" for moreinformation.
>>> import tab
>>> d={}
>>> d.
d.__class__(         d.__ge__(            d.__len__(           d.__setitem__(       d.has_key(           d.setdefault(
d.__cmp__(           d.__getattribute__(  d.__lt__(            d.__sizeof__(        d.items(             d.update(
d.__contains__(      d.__getitem__(       d.__ne__(            d.__str__(           d.iteritems(         d.values(
d.__delattr__(       d.__gt__(            d.__new__(           d.__subclasshook__(  d.iterkeys(          d.viewitems(
d.__delitem__(       d.__hash__           d.__reduce__(        d.clear(             d.itervalues(        d.viewkeys(
d.__doc__            d.__init__(          d.__reduce_ex__(     d.copy(              d.keys(              d.viewvalues(
d.__eq__(            d.__iter__(          d.__repr__(          d.fromkeys(          d.pop(              
d.__format__(        d.__le__(            d.__setattr__(       d.get(               d.popitem(          
>>> d.

 

增加字典元素

>>> nameinfo={}
>>> nameinfo['a1']='yangrong'   #若字典里有a1主键,则覆盖原来的值,没有,则添加
>>> nameinfo
{'a1': 'yangrong'}

 

遍历字典主键与键值

>>> for k, value innameinfo.items():
...  print k,value
...
a1 yangrong

 

查看字典所有主键

>>> dict = {'ob1':'computer','ob2':'mouse', 'ob3':'printer'}  
>>>
>>>
>>> dict.keys()
['ob2', 'ob3', 'ob1']

 

判断字典中是否有该主键

>>> dict.keys()
['ob2', 'ob3', 'ob1']
>>> dict.has_key('ob2')     #或'ob2' in dict
True
>>> dict.has_key('ob4')
False

 

也有人用循环方法来判断

for key in dict.keys():

但是这种方法毕竟不够简洁,

查看字典所有键值内容

>>> dict = {'ob1':'computer','ob2':'mouse', 'ob3':'printer'}
>>> dict.values()
['mouse', 'printer', 'computer']

 

列出所有项目

>>> dict.items()
[('ob2', 'mouse'), ('ob3', 'printer'),('ob1', 'computer')]

清空字典

>>> dict.clear()
>>> dict
{}

 

拷贝字典

>>> dict
{'ob2': 'mouse', 'ob3': 'printer', 'ob1':'computer'}
>>> a=dict
>>> a
{'ob2': 'mouse', 'ob3': 'printer', 'ob1':'computer'}
>>> b=dict.copy()
>>> b
{'ob2': 'mouse', 'ob3': 'printer', 'ob1': 'computer'}

 

比较字典

>>> cmp(a,b)

首先比较主键长度,然后比较键大小,然后比较键值大小,(第一个大返回1,小返回-1,一样返回0)

 

更新字典

>>>dict={'yangrong':{"age":"23","job":"IT"},"xiaohei":{"'age':'22','job':'dota'"}}
>>> dict
{'xiaohei':set(["'age':'22','job':'dota'"]), 'yangrong': {'age': '23', 'job':'IT'}}
 
>>> dict['xiaohei']=111        #修改一级字典
>>> dict
{'xiaohei': 111, 'yangrong': {'age': '23','job': 'IT'}}
>>> dict['yangrong']['age']=25    #修改二级字典
>>> dict
{'xiaohei': 111, 'yangrong': {'age': 25,'job': 'IT'}}
 
>>> dict={'yangrong':['23','IT'],"xiaohei":['22','dota']}
>>>dict['xiaohei'][1]="dota2"         #修改字典中列表某项,1是代表列表中第2个字符串。
>>> dict
{'xiaohei': ['22', 'dota2'], 'yangrong':['23', 'IT']}

 

删除字典元素

>>> dict
{'xiaohei': ['22', 'dota2'], 'yangrong':['23', 'IT']}
>>> del dict['xiaohei']          #删除xiaohei键值
>>> dict
{'yangrong': ['23', 'IT']}
 
 
>>> dict
{'yangrong': ['23', 'IT']}
>>>
>>> del dict['yangrong'][1]    #删除yangrong主键的每2字值
>>> dict
{'yangrong': ['23']}

 

删除整个字典

>>> dict
{'yangrong': ['23']}
>>> dict.clear()  #同del dict
>>> dict
{}

 

将字符串切分为列表

>>> s="hello world bye"
>>> s.split()    #用于把有规律的文本,读取出来后,使用列表进行修改,再写入文件。
['hello', 'world', 'bye']

 

将列表转换为字符串

S.split(str, ' ')  #将string转list,以空格切分

存储字典(pickle序列化)

#需导入pickle模块

 

把字典内容存入文件

f=file('data.txt','wb')   #新建文件data.txt,'wb',b是打开块文件,对于设备文件有用
pickle.dump(a,f)      #把a序列化存入文件
f.close()

把内容读入字典(反序列化)

a=open('data.txt','rb')    #打开文件
print pickle.load(a)      #把内容全部反序列化


转载于:https://blog.51cto.com/zhongguiyao/1855417