python列表练习题

===================

python列表练习题

===================

一、创建列表

1.创建一个列表，命名为names，往里面添加陈贤贤、大财神、飞鱼、WuYing、阿阳和Black元素。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
print(names)

结果[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]

2.列表文字的添加

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
print('我建的学习群有', len(names), '个学生在微信群里面')
print('我建的学习群有' + str(len(names)) + '个学生在微信群里面')

for item in names:
    print(names)
print('我在渡劫也加入了微信群')

names.append('我在渡劫')
print('现在我的微信群是', names)

结果：

我建的学习群有 6 个学生在微信群里面 #6的前后都有空格存在
我建的学习群有6个学生在微信群里面 # 6个前后没有空格存在
陈贤贤
大财神
飞鱼
WuYing
阿阳
Black
我在渡劫也加入了微信群
现在我的微信群是 [‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’, ‘我在渡劫’]

二、在列表中插入元素

1.往names列表中的最后一个元素Black前面插入一个张四岁。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names.insert(-1, "张四岁")
print(names)

结果[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘张四岁’, ‘Black’]

2.往names列表中最前面的元素陈贤贤前面插入张四岁

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names.insert(0, '张四岁')
print(names)

结果[‘张四岁’, ‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]

3.往names列表中中间部位的元素飞鱼前面插入张四岁

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names.insert(2, '张四岁')
print(names)

结果[‘陈贤贤’, ‘大财神’, ‘张四岁’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]

4.往names列表中大财神后面插入一个子列表[“老男孩”,“老女孩”]。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names.insert(2, ["老男孩", "老女孩"])
print(names)

结果：[‘陈贤贤’, ‘大财神’, [‘老男孩’, ‘老女孩’], ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]

三、改变列表中的某一个元素的名称

1.把names列表中WuYing的名字改成中文。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names[names.index("WuYing")] = "吴莹"
print(names)

结果：[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘吴莹’, ‘阿阳’, ‘Black’]

2.把names列表中飞鱼的名字改成数字666

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names[names.index('飞鱼')] = 666
print(names)

结果：[‘陈贤贤’, ‘大财神’, 666, ‘WuYing’, ‘阿阳’, ‘Black’]

3.修改特定元素

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names[3] = "吴莹"
print(names)

结果：[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘吴莹’, ‘阿阳’, ‘Black’]

4.批量修改元素名

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names[0:2] = 'abcd'  # 将索引0-2替换为abcd,切片之后迭代处理
print(names)

结果：[‘a’, ‘b’, ‘c’, ‘d’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]

四、确定列表中元素的位置（索引值）

1.返回names列表中阿阳的索引值（下标）。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
print(names.index("阿阳"))

结果：4

五、两个列表的合并

1.创建新列表numbers，依次包含1,2,3,4,2,5,6,2等数，并把新列表合并到names列表中。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
numbers = [1, 2, 3, 4, 2, 5, 6, 2]
names.extend(numbers)  # extend()方法表示合并
print(names)

结果：[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’, 1, 2, 3, 4, 2, 5, 6, 2]

六、取出列表中指定元素

1.取出names列表中索引4-7的元素。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black", 1, 2, 3, 4, 2, 5, 6, 2]
print(names[4:8])

结果：[‘阿阳’, ‘Black’, 1, 2]

2.取出names列表中索引2-10的元素，步长为2。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black", 1, 2, 3, 4, 2, 5, 6, 2]
print(names[2:11:2])  # 列表切片“顾头不顾尾”，步长表示在指定范围间隔取值

#结果：[‘飞鱼’, ‘阿阳’, 1, 3, 2]

3.取出names列表中最后3个元素。

names = ['陈贤贤', '大财神', ['老男孩', '老女孩'], '飞鱼', '吴莹', '阿阳', '张四岁', 'Black', 1, 2, 3, 4, 2, 5, 6, 2]
print(names[-3:])  # [-3:]表示取值范围为从列表的倒数第三个到末尾

结果：[5, 6, 2]

七、打印特定索引值和元素

1.循环names列表，打印每个元素的索引值和元素。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]

方法1

for i in names:
    print(names.index(i), i)

方法2 enumerate()枚举

for index, i in enumerate(names):
    print(index, i)

结果：

0 陈贤贤
1 大财神
2 飞鱼
3 WuYing
4 阿阳
5 Black

2.循环names列表，打印每个元素的索引值和元素，当索引值为偶数时，把对应的元素改成-1。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black", 1, 2, 3, 4, 2, 5, 6, 2]
for index, i in enumerate(names):
    if index % 2 == 0:
        names[index] = -1
        print(index, i)
print(names)

结果：[-1, ‘大财神’, -1, ‘WuYing’, -1, ‘Black’, -1, 2, -1, 4, -1, 5, -1, 2]

3.names列表里有3个2，请返回第二个2的索引值，不要人肉，要动态找。

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black", 1, 2, 3, 4, 2, 5, 6, 2]

方法1 循环

count = 0
for index, i in enumerate(names):
    # print(index,i)
    if i == 2:
        count += 1
        while count == 2:
            print(index)
            break
    else:
        continue

方法2

print(names.index(2, names.index(2)+1))

结果：10

4.现有商品列表如下：

products = [["iphone", 6888], ["MacPro", 14800], ["小米6", 2499], ["Coffee", 31], ["Book", 60], ["Nike", 699]]

需打印出以下格式：

------ 商品列表 ------
0 iphone 6888
1 MacPro 14800
2 小米6 2499
3 Coffee 31
4 Book 60
5 Nike 699

products = [["iphone", 6888], ["MacPro", 14800], ["小米6", 2499], ["Coffee", 31], ["Book", 60], ["Nike", 699]]
print("--------- 商品列表 --------")
for index, i in enumerate(products):
    print("%s %s %s" % (index, i[0], i[1]))

结果：

--------- 商品列表 --------
0 iphone 6888
1 MacPro 14800
2 小米6 2499
3 Coffee 31
4 Book 60
5 Nike 699

5.根据products列表写一个循环，不断询问用户想买什么，用户选择一个商品编号，就把对应的商品添加到购物车里，最终用户输入q退出时，打印购买的商品列表。

products = [["iphone", 6888], ["MacPro", 14800], ["小米6", 2499], ["Coffee", 31], ["Book", 60], ["Nike", 699]]
shop_car = []  # 用户购物车
shop_cost = 0  # 用户花费的金额
exit_log = False  # 标志位，默认设为False,退出
while not exit_log:
    print("------ 商品列表 ------")
    for index, i in enumerate(products):
        print("%s   %s  %s" % (index, i[0], i[1]))
    user_choice = input("\n输入你想购买的产品序号(按“q”退出):")
    if user_choice.isdigit():
        # 判断用户输入的是否是数字
        user_choice = int(user_choice)  # 强制转换为数字
        if user_choice >=0 and user_choice < len(products):
            # 判断用户购买的商品是否在商品列表中
            shop_car.append(products[user_choice])  # 加入购物车
            shop_cost += products[user_choice][1]  # 计算费用
            print("\n %s 已经加入你的购物车\n"%products[user_choice])
        else:
            print("抱歉，此商品不存在\n")
    elif user_choice == "q":
      # 用户选择退出
        if len(shop_car) > 0:
            # 判断用户是否购买了商品
            print("\n------ 你的购物车 ------")
            for index, i in enumerate(shop_car):
                # index和i为临时变量，与前一个for循环里index和i作用的列表不同，故可重用
                print("%s  %s" % (i[0], i[1]))
            print("\n你此次购物的花费合计是:%s元\n" % shop_cost)
            exit_log = True # 退出购物
        else:
            exit_log = True # 未购买商品，不打印购物车商品，直接退出
    else:
        # 输入不合法
        exit_log = True

6.打印列表本身

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
print(names)

结果：[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]

7.依顺序打印列表中所有元素

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]

方法一

print(names[0])
print(names[1])
print(names[2])
print(names[3])
print(names[4])

方法二

for i in names:
    print(i)

结果：[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]

8.调取一个列表元素的方法

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
print(names[3])

结果：WuYing

八、统计列表中元素的个数

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
print(len(names))

结果：6

九、增加列表中元素的方法：append方法

score = []
print(score)
score.append(80)
print(score)

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names.append(1705)
names.append('HZH')
print(names)

print(names.append('HZH'))  # 无返回值，names.append

结果：

[]
[80]
[‘陈贤贤’, ‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’, 1705, ‘HZH’]
None

十、列表转换成字符串

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
a = "、".join(names)
print(a)

结果：陈贤贤、大财神、飞鱼、WuYing、阿阳、Black

十一、删除元素

1.按照元素删除

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names.remove('飞鱼')
print(names)

结果：[‘陈贤贤’, ‘大财神’, ‘WuYing’, ‘阿阳’, ‘Black’]

2.按照索引删除

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names = names.pop()  # 不写索引就删除最后一个之外所有其他的
print(names)
‘’‘

结果：Black

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names = names.pop(2)  # 保留第3个，删除所有其他的
print(names)

结果：飞鱼

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
names = names.clear()  # 清除列表
print(names)

结果：None

names = ["陈贤贤", "大财神", "飞鱼", "WuYing", "阿阳", "Black"]
for i in range(len(names)):  # 一个一个地删除
    print(i)
    del names[0]
    print(names)

结果：

0
[‘大财神’, ‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]
1
[‘飞鱼’, ‘WuYing’, ‘阿阳’, ‘Black’]
2
[‘WuYing’, ‘阿阳’, ‘Black’]
3
[‘阿阳’, ‘Black’]
4
[‘Black’]
5
[]