什么是Namedtuples，如何使用Namedtuples
Namedtuples是一个轻量的并且很容易创建的对象类型
Namedtuples的实例可以像对象实例一样使用
Namedtuples跟struct很像
Namedtuples是不可变的
Namedtuples类型被添加在Python 2.6 和 Python 3.0
下面看个例子
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from math import sqrt
p1 = (1, 2)
p2 = (2, 3)
line_length = sqrt((p1[0] - p2[0])**2 + (p1[1] - p2[1])**2)
print(line_length)
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如果使用Namedtuples，上面代码的可读性将会稍微有些改善
下面看代码
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from math import sqrt
from collections import namedtuple
Point = namedtuple('Point', ['x', 'y'])
p1 = Point(1, 2)
p2 = Point(2, 3)
line_length = sqrt((p1.x - p2.x)**2 + (p1.y - p2.y)**2)
print(line_length)
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Namedtuples也兼容了第一个例子中的使用方式，代码如下
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from math import sqrt
from collections import namedtuple
Point = namedtuple('Point', ['x', 'y'])
p1 = Point(1, 2)
p2 = Point(2, 3)
line_length = sqrt((p1[0] - p2[0])**2 + (p1[1] - p2[1])**2)
print(line_length)
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Point = namedtuple('Point', ['x', 'y'])
这段代码也可以用下面的方式来声明
Point = namedtuple('Point', ('x y'))
用个例子来说明下
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from math import sqrt
from collections import namedtuple
Point = namedtuple('Point', ('x y'))
p1 = Point(1, 2)
p2 = Point(2, 3)
line_length = sqrt((p1[0] - p2[0])**2 + (p1[1] - p2[1])**2)
print(line_length)
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再来看下，Namedtuples是如何不可变的
示例如下
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from collections import namedtuple
Point = namedtuple('Point', ('x y'))
p = Point(1, 2)
p.x = 3
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运行结果报错如下
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Traceback (most recent call last):
File "main.py", line 95, in <module>
p.x = 3
AttributeError: can't set attribute
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参考文章：地址
