python collections 数据结构模块

Posted 2020-10-23 FRESHMANS

 

namedtuple类

导入模块

from collections import namedtuple

 

使用方法及说明

#pycharm 里按住 ctrl键点击 collections可查看源码

#collections数据结构
#__all__ = [‘deque‘, ‘defaultdict‘, ‘namedtuple‘, ‘UserDict‘, ‘UserList‘,‘UserString‘, ‘Counter‘, ‘OrderedDict‘, ‘ChainMap‘]

使用说明：

#猜包功能

name = ("lijie",‘ll‘)
user = ("aa",23,189,‘boddy‘)

username,age,height，edu = user
print (username,age,height,edu)

打印结果:
aa 23 189 boddy

#另一种方法
username,*other = user
print (username,other)

打印结果：
aa [23, 189, ‘boddy‘]

 

tuple 可作为字典的key，而list不可以，示例：

name_tuple = ("test",22,185,"baskerball")
name_list = ["test1",22,188,"baseball"]

dd = {}
dd[name_tuple] = ‘boddy‘
print (dd)

dd[name_list] = ‘body‘
print (dd)

打印结果：

{(‘test‘, 22, 185, ‘baskerball‘): ‘boddy‘}

Traceback (most recent call last):
File "D:/python-script/collections_module/chapter1/collection_module.py", line 29, in <module>
dd[name_list] = ‘body‘
TypeError: unhashable type: ‘list‘