python的學習筆記/002-3（2018-5-20）

標籤：列表（list）的常見操作

群集類型

群集類型	列表	元組	字典	集合
	list	tuple	dict	set

1.列表
列表的類型是list,特點為有序，具備索引，內容與長度可以變動。要建立列表，可以使用[]直接標記法，列表中每個元素使用逗號分隔開。
列表的常見操作
(1) 元素的切片

names=["Zhangfei","Guanyu","Liubie","Zhaoyun","Machoa","Jiangwei","Mashu","Zhaoyun"]print(names)print(names[0])    # 切位置0的元素print(names[0:4])  #  切出位置0~3的元素print(names[-1])     # 切出最後一位的元素print(names[-3:])     # 切片，左取右不取``print(names[0:-1:2])    # 有間隔的切片for i in names:    print(i)           # 迴圈的切片方法，這個i就代表了列表中的元素

(2) 列表的增，改，刪
names.append();names.insert();names.remove();names.pop()

names=["Zhangfei","Guanyu","Liubie","Zhaoyun","Machoa","Jiangwei","Masu","Zhaoyun"]print(names)names.append("Zhugelaing")   # [增]-----在列表末尾  追加  諸葛亮print(names)names.insert(3,"daqiao")       # [增]-----在列表中的位置3  插入  大喬print(names)names[2]="zhouyu"            #[改]----- 將劉備  替換  為周瑜print(names)   # names.remove("Masu")      # [刪]-----刪除 馬謖 (有三種常用的方法)# del names[-3]print(names.pop(-3))print(names)

(3) 列表的查，統計
names.index();names.count()

names=["Zhangfei","Guanyu","Liubie","Zhaoyun","Machoa","Jiangwei","Masu","Zhaoyun"]print(names)print(names.index("Zhaoyun"))         # 擷取下標，趙雲有倆個但是卻只查到了列表裡的第一個？？？？print(names[names.index("Zhaoyun")])print(names.count("Zhaoyun") )     #   統計  列表中趙雲的個數

(4) 列表的反轉，排序，合并
names.reverse();names,sort();names.extend()

names=["Zhangfei","Guanyu","Liubie","Zhaoyun","Machoa","Jiangwei","Masu","Zhaoyun"]print(names)names.reverse()    #  將列表  反轉print(names)names.sort()    # 將列表按照預設的utf-8格式  排序print(names)names2=["Chaochao","Simayi","Diewei","Xiahuodong","Xuchu"]names.extend(names2 )       #  合并倆個列表，但是合并的列表仍然存在print(names)

(5) 列表的複製
names.copy();copy.copy();copy.deepcopy()

import copy  # 需要為深copy引入模組names=["Zhangfei","Guanyu","Liubie","Zhaoyun",["zhouyu","daqiao"],"Machoa","Jiangwei","Masu","Zhaoyun"]names1=names    #  完全就是二者相等names2=names.copy()   # 淺copy，第二個列表裡其實copy的是一個地址，可以用來實現一個聯合賬戶的功能names3=copy.copy(names) # 三種不同的實現方法names4=names[:]names5=copy.deepcopy(names)   #  深copy一般不用因為會佔用更多的空間names[2]="劉邦"     #  將位置2的元素改為劉邦names[4][0]="小喬"   # 將位置4列表裡的位置0元素改為大喬print(names)   # 比較幾種不同的複製print(names1)print(names2)print(names3)print(names4)print(names5)

(6) 列表的清除
names.clear()

names=["Zhangfei","Guanyu","Liubie","Zhaoyun","Machoa","Jiangwei","Masu","Zhaoyun"]print(names)names.clear()print(names)

python的學習筆記/002-3（2018-5-20）