先看图片解释
lst = ['arwen',123]print(lst[0])print(st[1])lst[0] = 'weiwen'
(2)元组
tup = ('arwen',123)print(tup[0])print(tup[1])
元组和列表在结构上没有什么区别,唯一的差异在于元组是只读的,不能修改。元组用“()”表示,如:
(3)集合就是我们数学学的集合,没有什么特殊的定义。集合最好的应用是去重。集合没有特殊的表示方法,而是通过一个set函数转换成集合,如:
lst = [ 1, 1, 0]lst_set = set( lst ) #lst_set 为1 , 0tup = (2, 2, 1)tup_set = set( tup) # tup_set为2 , 1for item in lst_set: print(item)
(4)最后一个是字典。字典存储键值对数据,如:
lists = {1:'a',2:'b',3:'c'}#字典最外面用大括号,每一组用冒号连起来,然后各组用逗号隔开。#字典最大的价值是查询,通过键,查找值。
1、列表元组转其他
# 列表转集合(去重)list1 = [6, 7, 7, 8, 8, 9]set(list1)# {6, 7, 8, 9}#两个列表转字典list1 = ['key1','key2','key3']list2 = ['1','2','3']dict(zip(list1,list2))# {'key1': '1', 'key2': '2', 'key3': '3'}#嵌套列表转字典list3 = [['key1','value1'],['key2','value2'],['key3','value3']]dict(list3)# {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}# 列表、元组转字符串list2 = ['a', 'a', 'b']''.join(list2)# 'aab'tup1 = ('a', 'a', 'b')''.join(tup1)# 'aab
2、字典转其他
# 字典转换为字符串dic1 = {'a':1,'b':2}str = str(dic1)print(str)# "{'a': 1, 'b': 2}"# 字典key和value互转dic2 = {'a': 1, 'b': 2, 'c': 3}dic3 = {value:key for key, value in dic2.items()}print(dic3)# {1: 'a', 2: 'b', 3: 'c'}
3、字符串转其他
# 字符串转列表s = 'aabbcc'list(s)# ['a', 'a', 'b', 'b', 'c', 'c']# 字符串转元组tuple(s)# ('a', 'a', 'b', 'b', 'c', 'c')# 字符串转集合set(s)# {'a', 'b', 'c'}# 字符串转字典dic2 = eval("{'name':'ljq', 'age':24}")# 切分字符串a = 'a b c'a.split(' ')# ['a', 'b', 'c']
二、字典的分割、合并
#分割:base = {'A':1, 'B':2, 'C':3, 'D':4, 'E':5}subkey = ['C', 'E']subdict=dict([(key, base[key]) for key in subkey])print(subdict)#{'C': 3, 'E': 5}#合并:#方式一:d1={'user':'root','pwd':'1234'}d2={'ip':'127.0.0.1','port':8080}d3=dict(d1, **d2)print(d3)#方式二:d1={'user':'root','pwd':'1234'}d2={'ip':'127.0.0.1','port':8080}d3={}for k,v in d1.items(): d3[k] = vfor k,v in d2.items(): d3[k] = vprint(d3)
三、list分割、合并
a=[1,2,3,4,5,6]b=['a','b','c','d']print(a+b)a=[1,2,3,4,5,6]b=['a','b','c','d']a+=bprint(a)a=[1,2,3,4,5,6]b=['a','b','c','d']a.extend(b)print(a)a=[1,2,3,4,5,6]b=['a','b','c','d']a[0:0]=bprint(a)li = ['a','b','c']res1=';'.join(li)res2=''.join(res1).split(';')
https://www.cnblogs.com/wlgaojin/p/12307800.html
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