Python字典clear（）-yiteyi-C++库

clear（）方法从字典中删除所有项。

null

语法：

dict.clear()

参数：

The clear() method doesn't take any parameters.

返回：

The clear() method doesn't return any value.

例如：

Input : d = {1: "geeks", 2: "for"}
        d.clear()
Output : d = {}

错误：

As we are not passing any parameters there
is no chance for any error.

                     # Python program to demonstrate working of                   
                     # dictionary clear()                   
                     text                               =                               {                               1                               :                               "geeks"                               ,                               2                               :                               "for"                               }                   
                             
                     text.clear()                   
                     print                               (                               'text ='                               , text)                   

输出：

text = {}

把{}赋值给字典有什么不同？ 请参考下面的代码以查看差异。当我们将{}分配给字典时，会创建一个新的空字典并将其分配给引用。但是，当我们清除字典引用时，实际的字典内容将被删除，因此所有引用字典的引用都将变为空。

                     # Python code to demonstrate difference                   
                     # clear and {}.                   
                             
                     text1                               =                               {                               1                               :                               "geeks"                               ,                               2                               :                               "for"                               }                   
                     text2                               =                               text1                   
                             
                     # Using clear makes both text1 and text2                   
                     # empty.                   
                     text1.clear()                   
                             
                     print                               (                               'After removing items using clear()'                               )                   
                     print                               (                               'text1 ='                               , text1)                   
                     print                               (                               'text2 ='                               , text2)                   
                             
                     text1                               =                               {                               1                               :                               "one"                               ,                               2                               :                               "two"                               }                   
                     text2                               =                               text1                   
                             
                     # This makes only text1 empty.                   
                     text1                               =                               {}                   
                             
                     print                               (                               'After removing items by assigning {}'                               )                   
                     print                               (                               'text1 ='                               , text1)                   
                     print                               (                               'text2 ='                               , text2)                   

输出：

After removing items using clear()
text1 = {}
text2 = {}
After removing items by assigning {}
text1 = {}
text2 = {1: 'one', 2: 'two'}

文章版权归作者所有，未经允许请勿转载。

THE END

Python