python 3 列表元組字典集合
2023-02-27 16:13 作者:戎碼關(guān)山 | 我要投稿
列表
#list
empty_list = []
numlist = [1,5,3,4,2]
mixlist = ['name',100,200]
list_in_list = [1,2,[3,4,5]]
list_use_fuction = list("hello word")
print(list_use_fuction)
#list拆分
hero = ['dd',24,173]
name,age,height = hero
print(name)
#list索引
print(hero[1])
print(list_in_list[2][2])
print([1,2,3,4,5][-1])#list可以自身索引不需名字
#切片
print(list_use_fuction[::2])#取偶數(shù)位的字母
#函數(shù)
print(len(list_use_fuction))
print(max(numlist))
print(sum(numlist))
print(sorted(numlist))
i = reversed(numlist)
next(i)#reversed返回的是一個(gè)迭代器，需要用next返回
#list改變
numlist[0] = 100;
print(numlist)
numlist[1:3] = "hello"
print(numlist)#[100, 'h', 'e', 'l', 'l', 'o', 4, 2]
numlist[:] = [6,7,2,5,1,8,9,0,6,6]
print(numlist)
#list方法
print(numlist.index(7))#檢索
print(numlist.count(6))
numlist.append(666)#增加元素
print(numlist)
numlist.insert(0,100)
print(numlist)
numlist.remove(6)#刪除元素
print(numlist)
first = numlist.pop(0)#刪除并返回
del numlist[1:]#刪除多個(gè)元素
print(numlist)
#列表推導(dǎo)式
#【表達(dá)式 for 變量 in 列表 if 條件】
#求1000以內(nèi)3和5的倍數(shù)之和
print(sum([i for i in range(0,1000) if i%3 == 0 or i%5 == 0 ]))
#使用生成器表達(dá)式，不是真正創(chuàng)建列表，而是返回一個(gè)生成器，可以用迭代的方法獲得生成器的值，最大的優(yōu)點(diǎn)就是節(jié)省內(nèi)存
#具體就是將上面的[]換成()
print(sum((i for i in range(0,1000) if i%3 == 0 or i%5 == 0 )))
#copy and deepcopy
import copy
a = [1,2,3]
b = copy.copy(a)
c = copy.deepcopy(a)
a.remove(1)
print(a)
print(b)
print(c)元組
元組可以看做是不可變的列表
#元組
t1 = tuple()
t2 = ()
t3 = (1,2,3)
t4 = tuple("hello")
print(t4)
#zip
t5 = [1,2,3,4,5]
t6 = '123'
for i in zip(t4,t5,t6):#接收多個(gè)序列，每個(gè)序列順序選取一個(gè)值放入一個(gè)元組
? ?print(i)字典
#dict
d = dict()
hero = {'name':'dd','age':24,'weight':75}
print(hero)
print(hero['name'])
#functions
print(hero.keys())
print(hero.values())
for k,v in hero.items():
? ?print(k + ' ===> ' + str(v))集合
#set
null = set()
aset = set("aaaab")
bset = set('abc')
print(aset)
print(aset.intersection(bset))#交集，并集，差集
print(aset.union(bset))
print(bset.difference(aset))
print(aset.symmetric_difference(bset))#對(duì)稱差，保留兩個(gè)集合中不同的元素
#issubset,isuperset判斷子集和超集
#function
bset.add('d')
bset.remove('a')
print(bset)
bset.clear()標(biāo)簽：
