day7 --作业

统计某个元素在列表中出现的次数

names = ["曹操","刘备","赵云","小乔","貂蝉","吕布","诸葛亮","司马懿","小乔"]
count = 0
value = "小乔"
for index in range(len(names)):
    if names[index] == value:
        count += 1
print(count)

在列表末尾一次性追加另一个序列中的多个值(用新列表扩展原来的列表)

names = ["曹操","刘备","赵云","小乔","貂蝉","吕布","诸葛亮","司马懿","小乔"]
value = list(input("请输入一个序列："))
for index in range(len(value)):
    names.append(value[index])
print(names)
# print(names + value)

从列表中找出某个值第一个匹配项的索引位置

names = ["曹操","刘备","赵云","小乔",("貂蝉","吕布"),"诸葛亮","司马懿","小乔","貂蝉","吕布","诸葛亮","司马懿","小乔"]
value = ("貂蝉","吕布")
for index in range(len(names)):
    if names[index] == value:
        print(index)
        break

反向列表中元素

names = ["曹操","刘备","赵云","小乔","貂蝉","吕布","诸葛亮","司马懿","小乔"]
for index in range(len(names)):
    for index1 in range(len(names)):
        if index > index1:
            names[index],names[index1] = names[index1],names[index]
            # print(names)
print(names)