python中的字典

Dictionaries contain key:value pairs. Which means a collection of tuples with an attribute name and an assigned value to it. The semicolon present in between each key and values and attribute with values are delimited with a comma.  In python we can define dictionaries using dictionary construct.

字典包含键：值对。 这意味着具有属性名称和赋值的元组的集合。 每个键与值之间的分号和带有值的属性之间用逗号分隔。 在python中，我们可以使用字典构造来定义字典。

First of all we need to define a dictionary:

首先，我们需要定义一个字典：

Syntax:

句法：

    
     = {
     
       : 
      
        , 
       
         : 
        
         ,...., 
         
           : 
          
            }
          
         
        
       
      
     
    

From the above syntax the value can be integer may not be enclosed by single/double quotes and separated by commas.

根据上述语法，该值可以是整数，不能用单引号/双引号引起来，而用逗号分隔。

Example:

例：

>>> COURSE ={'ORACLE': 1 ,'LINUX' : 2, 'SHELL' : 3 ,'PERL' : 4 }>>> type(COURSE)
    

The dictionaries are also case sensitive. We can access the above dictionary as like below:

字典也区分大小写。 我们可以像下面这样访问上面的字典：

>>> COURSE{'ORACLE': 1, 'PERL': 4, 'SHELL': 3, 'LINUX': 2}

If we want to display the value specifically then we can call the dictionary by each key as like below:

如果要具体显示该值，则可以按每个键调用字典，如下所示：

>>> COURSE ['PERL']4

Now if we want to add another element let say ‘PYTHON’ as value 4 then use as below:

现在，如果我们要添加另一个元素，请说“ PYTHON”作为值4，然后按如下所示使用：

>>> COURSE ['PYTHON']  = 4>>> COURSE{'ORACLE': 1, 'PERL': 4, 'PYTHON': 4, 'SHELL': 3, 'LINUX': 2}>>>

Now if I want to change the value of the key Linux then we have to use as like below:

现在，如果我想更改密钥Linux的值，则必须使用如下所示的代码：

>>> COURSE ['PYTHON']  = 9>>> COURSE{'ORACLE': 1, 'PERL': 4, 'PYTHON': 9, 'SHELL': 3, 'LINUX': 2}>>>

>>> COURSE.keys()['ORACLE', 'PERL', 'PYTHON', 'SHELL', 'LINUX']>>> COURSE.values()[1, 4, 9, 3, 2]

For deleting the key value pair from the dictionary created then we have to use :

为了从创建的字典中删除键值对，我们必须使用：

>>> del COURSE['PERL']>>> COURSE{'ORACLE': 1, 'PYTHON': 9, 'SHELL': 3, 'LINUX': 2}>>>

Let us see how we can loop the dictionary values:

让我们看看如何循环字典值：

>>> for key,val in COURSE.iteritems():                print key,val                ORACLE 1PYTHON 9SHELL 3LINUX 2>>>

 For more information on dictionaries please visit :

有关字典的更多信息，请访问：

翻译自:

python中的字典