Python 入门例子0005

在本例中可以练习列表的排序。

1. 去除words 列表中重复的元素

code:

words = [

('Thanksgiving', '18', 9, 0, 0),

('white', '21', 8, 1, 1),

('garden', '4', 4, 3, 1),

('hospital', '2', 7, 5, 1),

('ninety-nine', '0', 8, 7, 1),

('strong', '12', 4, 11, 1),

('engineer', '16', 2, 0, 1),

('strict', '7', 2, 13, 1),

('wind', '8', 13, 9, 1),

('engineer', '16', 2, 0, 1),

('strict', '7', 2, 13, 1),

('wind', '8', 13, 9, 1)];

words = list(set(words ));

words

输出：

Out[77]:

[('ninety-nine', '0', 8, 7, 1), ('strict', '7', 2, 13, 1), ('engineer', '16', 2, 0, 1), ('wind', '8', 13, 9, 1), ('strong', '12', 4, 11, 1), ('white', '21', 8, 1, 1), ('Thanksgiving', '18', 9, 0, 0), ('hospital', '2', 7, 5, 1), ('garden', '4', 4, 3, 1)]

2. 按列表元素的两个属性排序, 本例中按照每个tuple元素索引为2和3的属性进行排序

code:

wordschaos = [('ninety-nine', '0', 8, 7, 1),

('strict', '7', 2, 13, 1),

('engineer', '16', 2, 0, 1),

('wind', '8', 13, 9, 1),

('strong', '12', 4, 11, 1),

('white', '21', 8, 1, 1),

('Thanksgiving', '18', 9, 0, 0),

('hospital', '2', 7, 5, 1),

('garden', '4', 4, 3, 1)];

wordsbyorder = sorted(wordschaos, key=lambda tup:( tup[2],tup[3]));

wordsbyorder

wordsbyorder = sorted(wordschaos, key=lambda tup:( tup[2],tup[3]));

wordsbyorder

输出为：

[('engineer', '16', 2, 0, 1), ('strict', '7', 2, 13, 1), ('garden', '4', 4, 3, 1), ('strong', '12', 4, 11, 1), ('hospital', '2', 7, 5, 1), ('white', '21', 8, 1, 1), ('ninety-nine', '0', 8, 7, 1), ('Thanksgiving', '18', 9, 0, 0), ('wind', '8', 13, 9, 1)]

知识点：

Lambda表达式:

在Python、C++等语言里都有Lambda表达式，又称为匿名表达式。这种能够接受一个函数作为参数的函数叫做「高阶函数」（higher-order function），是来自函数式编程（functional programming）的思想。 对抽象思维的要求较高。

一个简单的Lambda 表达式：

调用它运行：

输出结果为：

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