新聞中心
這里有您想知道的互聯(lián)網(wǎng)營銷解決方案
創(chuàng)新互聯(lián)Python教程:Python之列表的增刪改查

按需開發(fā)可以根據(jù)自己的需求進行定制,成都網(wǎng)站設計、網(wǎng)站制作構思過程中功能建設理應排到主要部位公司成都網(wǎng)站設計、網(wǎng)站制作的運用實際效果公司網(wǎng)站制作網(wǎng)站建立與制做的實際意義
列表的查
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a[1:4])
結果:
['tom', 'jack', 'james']
注意:
列表的切片的下標以 0 為開始。即: 下標0 --> klvchen,下標1 --> tom,..... 下標5 --> lucy。
列表的切換顧頭不顧尾,例如:a [1:4],則不會取到列表下標為4的元素
從左到右,取到最后:
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a[1:])
結果:
['tom', 'jack', 'james', 'lily', 'lucy']
從左到右,取到倒數(shù)第二個值:
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a[1:-1])
結果:
['tom', 'jack', 'james', 'lily']
從左到右,隔一個去?。?/p>
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a[1::2])
結果:
['tom', 'james', 'lucy']
從右到左,一個一個去?。?/p>
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a[3::-1])
結果:
['james', 'jack', 'tom', 'klvchen']
從右到左去取
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a[-2:-4:-1])
結果:
['lily', 'james']
列表的增
append 方法默認插到最后一個位置
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"]
a.append("mary")
print(a)結果:
['klvchen', 'tom', 'jack', 'james', 'lily', 'lucy', 'mary']
insert 方法將數(shù)據(jù)插入到任意一個位置
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] a.insert(1,"mary") print(a)
結果:
['klvchen', 'mary', 'tom', 'jack', 'james', 'lily', 'lucy']
extend 方法可在列表的末尾一次性追加另一個序列中的多個值
a = ["klvchen", "tom", "jack"] b = ["james", "lily", "lucy"] a.extend(b) print(a)
結果:
['klvchen', 'tom', 'jack', 'james', 'lily', 'lucy']
相關推薦:《python視頻教程》
列表的改
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] a[1]="tom2" print(a)
結果:
['klvchen', 'tom2', 'jack', 'james', 'lily', 'lucy'] a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] a[1:3]=["tom2", "jack2"] print(a)
結果:
['klvchen', 'tom2', 'jack2', 'james', 'lily', 'lucy']
列表的刪
remove 方法
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"]
a.remove("tom")
print(a)結果:
['klvchen', 'jack', 'james', 'lily', 'lucy']
pop 方法
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] b = a.pop(1) print(a) print(b)
結果:
['klvchen', 'jack', 'james', 'lily', 'lucy'] tom
注意 pop 方法會返回刪除的元素
del 方法
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] del a[1] print(a)
結果:
['klvchen', 'jack', 'james', 'lily', 'lucy'] a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] del a print(a)
結果:
NameError: name 'a' is not defined
注意:del a 把列表a從內(nèi)存刪除了,所以打印 a 列表程序會報錯
列表元素的統(tǒng)計
list = ['a', 'a', 'b', 'c']
res = list.count('a')
print(res)結果:
2
列表的排序
sort 方法
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a) a.sort() print(a)
結果:
['klvchen', 'tom', 'jack', 'james', 'lily', 'lucy'] ['jack', 'james', 'klvchen', 'lily', 'lucy', 'tom']
reverse 方法
a = ["klvchen", "tom", "jack", "james", "lily", "lucy"] print(a) a.reverse() print(a)
結果:
['klvchen', 'tom', 'jack', 'james', 'lily', 'lucy'] ['lucy', 'lily', 'james', 'jack', 'tom', 'klvchen']
當前名稱:創(chuàng)新互聯(lián)Python教程:Python之列表的增刪改查
文章網(wǎng)址:http://m.5511xx.com/article/dphepsc.html


咨詢
建站咨詢
