day16_作业

3.用map来处理字符串列表,把列表中所有人都变成sb,比方alex_sb

name=['alex','wupeiqi','yuanhao','nezha']
name1 =[]
def func(s):
    return (s+"_sb")

t = map(func,name)  # t是迭代器
for i in t:
    print(i)
    name1.append(i)
print(name1)

4.用filter函数处理数字列表，将列表中所有的偶数筛选出来

num = [1,3,5,6,7,8]
def func(s):
    return s % 2 == 0
t = filter(func,num)    #迭代器
for i in t:
    print(i)
-------------------------------

s = filter(lambda  s:s % 2 == 0,num)    
for i in s:
    print(i)

 # 5.随意写一个20行以上的文件 运行程序，先将内容读到内存中，用列表存储。 接收用户输入页码，每页5条，仅输出当页的内容

with open("1",encoding="utf-8") as f:
    l = f.readlines()
    # print(l)
page,mod = divmod(len(l),5)     #divmod(被除数，除数)-----商，余数
if mod:
    page +=1    #有余数则页数加一
while True:
    page_num = int(input("请输入页数："))
    if page_num < 1:
        print("请输入正常页数")
    elif page_num>page:
        print("页数超出")
    else:
        str1 = l[(page_num - 1)*5:page_num *5]
        for i in str1:
            print(i.strip())