names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"] #列表存儲，類似數組

2、列表的操作

（1）切片

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"] #列表存儲，類似數組
print(names[1],names[3]) #取值，1、3代表下標，從左到右的位置
執行結果：
Guyun Xuliangchen

print(names[1:3]) #切片,顧頭不顧尾取[1]、[2]的值
print(names[0:3]) #切片
print(names[:3]) #等同於0:3，從下標0到3
print(names[-1]) #切片,取倒數第一個值
print(names[-2]) #取倒數第二個值
print(names[-2:]) #取最後兩個值
 

（2）增加--append：

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
names.append("LeiHaidong") #追加到最後
print(names)
執行結果：
[‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘, ‘LeiHaidong‘]

（3）修改--insert：

names.insert(1,"Chenronghua")  #數據插入，插在哪個位置前面就寫這個元素的下標,如插在Guyun前面
names.insert(3,"Xinzhiyu") #插在Guyun後面
print(names)
執行結果：
[‘ZhangYang‘, ‘Chenronghua‘, ‘Guyun‘, ‘Xinzhiyu‘, ‘Xiangpeng‘, ‘Xuliangchen‘, ‘LeiHaidong‘]
 

（4）查詢--index：

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
print(names)
print(names.index("Xiangpeng")) #查出Xiangpeng的位置
print(names[names.index("Xiangpeng")]) #獲取下標內容
執行結果：
[‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘]
2
Xiangpeng

（5）統計--count：

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
print("count-->",names.count("ZhangYang"))
執行結果：
count--> 1
 

（6）反轉--reverse:

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
names.reverse()
print(names)
執行結果：
[‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘]
reverse--> [‘Xuliangchen‘, ‘Xiangpeng‘, ‘Guyun‘, ‘ZhangYang‘]

（7）擴展--extend：

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
names2 = [1,2,3,4]
print(names)
names.extend(names2)
print("extend-->",names)
執行結果：
[‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘]
extend--> [‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘, 1, 2, 3, 4]

（8）排序--sort：

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
names.sort()
print(names)
執行結果：
[‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘, ‘ZhangYang‘]

（9）清除--clear：

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
names.clear()
print(names)
執行結果：
[]

（10）復制--copy：

names = ["ZhangYang","Guyun","Xiangpeng","Xuliangchen"]
names2 = names.copy()
print(names)
print(names2)
names[1] = "古雲"  #更改Guyun,可以看到names2中並沒有修改
print("names-->",names)
print("names2-->",names2)
執行結果：
[‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘]
[‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘]
names--> [‘ZhangYang‘, ‘古雲‘, ‘Xiangpeng‘, ‘Xuliangchen‘]
names2--> [‘ZhangYang‘, ‘Guyun‘, ‘Xiangpeng‘, ‘Xuliangchen‘]

（11）列表嵌套復制--copy.deepcopy：

names = ["ZhangYang","Guyun",["alex","jack"],"Xiangpeng","Xuliangchen"] 
names2 = names.copy()
print(names)
print(names2)
names[1] = "古雲"
names[2][0] = "ALEX" #更改列表中的alex為ALEX,可以看到names2中也相應更改
print("names-->",names)
print("names2-->",names2)
執行結果：
[‘ZhangYang‘, ‘Guyun‘, [‘alex‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]
[‘ZhangYang‘, ‘Guyun‘, [‘alex‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]
names--> [‘ZhangYang‘, ‘古雲‘, [‘ALEX‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]
names2--> [‘ZhangYang‘, ‘Guyun‘, [‘ALEX‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]

★★★★註意：這裏的的copy只會拷貝第一層，列表中包含列表，其中列表是指向存放列表的內存地址，所以在更改列表中的元素時，拷貝的部分也會相應地更改。

為了實現深入拷貝，可以導入copy模塊：
import copy
names2 = copy.deepcopy(names)
print(names)
print(names2)
names[1] = "古雲"
names[2][0] = "ALEX"
print("names-->",names)
print("names2-->",names2)
執行結果：
[‘ZhangYang‘, ‘Guyun‘, [‘alex‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]
[‘ZhangYang‘, ‘Guyun‘, [‘alex‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]
names--> [‘ZhangYang‘, ‘古雲‘, [‘ALEX‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]
names2--> [‘ZhangYang‘, ‘Guyun‘, [‘alex‘, ‘jack‘], ‘Xiangpeng‘, ‘Xuliangchen‘]

可以看到拷貝是完全克隆過來的，但是生產過程中一般不會使用，拷貝多一份數據，等於多占據了一份內存空間。

（12）for循環列表：

names = ["ZhangYang","Guyun",["alex","jack"],"Xiangpeng","Xuliangchen"] 
for i in names:
    print(i)
執行結果：
ZhangYang
Guyun
[‘alex‘, ‘jack‘]
Xiangpeng
Xuliangchen

（13）步長切片：

names = ["ZhangYang","Guyun",["alex","jack"],"Xiangpeng","Xuliangchen"] 
print(names[0:-1:2]) #打印第一個到最後一個，步長為2
執行結果：
[‘ZhangYang‘, [‘alex‘, ‘jack‘]]

3、程序練習

程序：購物車程序

需求:

啟動程序後，讓用戶輸入工資，然後打印商品列表
允許用戶根據商品編號購買商品
用戶選擇商品後，檢測余額是否夠，夠就直接扣款，不夠就提醒
可隨時退出，退出時，打印已購買商品和余額

#!/usr/bin/python
# _*_ coding:utf-8 _*_
# Aothr: Kim

goods_list = [
    [‘Iphone‘,5800],
    [‘Mac pro‘,9800],
    [‘Bike‘,800],
    [‘Watch‘,10600],
    [‘Coffee‘,31],
    [‘Alex Python‘,120]
]
shopping_list = [] #此列表為空當做購物車使用
salary = input("Please input your salary:")
if salary.isdigit():
    salary = int(salary)
    while True:
        for index,item in enumerate(goods_list): #enumerate可以取出列表的下標和內容
            print(index,item)
        user_choice = input("請選擇你需要的商品編號：")
        if user_choice.isdigit():
            user_choice = int(user_choice)
            if user_choice < len(goods_list) and user_choice >= 0: #len可以取出列表的長度
                g_item = goods_list[user_choice]
                if g_item[1] <= salary:
                    shopping_list.append(g_item)
                    salary -= g_item[1]
                    print("已成功添加商品%s到購物車，當前余額為\033[31;1m%s\033[0m" % (g_item, salary))
                else:
                    print("您的余額為%s，無法購買此商品，請充值！"%salary)
            else:
                print("您的選擇的商品編號%s有誤，請重新選擇:"%user_choice)
        elif user_choice == ‘q‘:
            print(‘------goods list------‘)
            for p in shopping_list:
                print(p)
            print("您當前余額為%s"%salary)
            exit()
        else:
            print("您的輸入有誤，請輸入正確的商品編號！")

Python入門篇（三）之列表