Python头歌实训之列表

1.欧拉筛法求素数

n = eval(input())
#代码开始
l = []
for i in range(2,n+1):
    l.append(i)
for j in l:
    for k in l:
        if k%j == 0 and k != j:
            l.remove(k)
#代码结束
print(l)

2.统计文档中诗人列表

f1 = open("sy8//中学诗词.txt","r",encoding='utf-8')
zj = []
#代码开始
for i in f1:
    if i.find('！') == -1 and i.find('。') == -1 and i.find('，') == -1 and i.find(' ') != -1:
        i = i.strip()
        x = i.rfind(' ')
        n = i[x+1:]
        if n not in zj:
            zj.append(n)
zj.sort()
#代码结束
for i in range(1, len(zj)+1):
    print(i, zj[i-1])
f1.close()

3.使用列表求解约瑟夫环

n = eval(input("输入人数"))
m = eval(input("输入序号"))
#代码开始
l, k, x = [], [], 0
for i in range(1, n+1):
    l.append(i)
while len(k) < n:
    for i in l:
        x += 1
        if x == m:
            print(i)
            x = 0
            k.append(i)
    for j in k:
        if j in l:
            l.remove(j)
#代码结束

4.两数之和

l1 = [1,4,5,6,7,8,9,10,11,12,13,15,18,19,20,21,29,34,54,65]
n = eval(input("请输入n"))
#代码开始
a, x = -1, 0
for i in l1:
    a += 1
    b = -1
    for j in l1:
        b += 1
        if i + j == n:
            print(a, b)
            x = 1
    if x == 1:
        break
if x == 0:
    print('not found')
#代码结束

5.用户数据的增加、删除、查询

yhlb=["mary","harry","mike","tom","rose"]
mmlb=["123456","888888","999999","765432","678901"]
print("""请选择
1 用户增加
2 用户删除
3 用户查询
4 查看数据,退出系统""")
#代码开始
while True:
    x = eval(input('请输入'))
    if x == 1:
        n = input('请输入用户名')
        s = input('请输入密码')
        if n in yhlb:
            print('用户已经存在 无法增加')
        else:
            yhlb.append(n)
            mmlb.append(s)
            print('用户已增加')
    elif x == 2:
        n = input('请输入用户名')
        if n not in yhlb:
            print('用户不存在 无法删除')
        else:
            yhlb.remove(n)
            k = -1
            for i in yhlb:
                k += 1
                if i == n:
                    mmlb.remove(mmlb[k])
            print('用户已删除')
    elif x == 3:
        n = input('请输入用户名')
        if n not in yhlb:
            print('用户不存在')
        else:
            k = -1
            for i in yhlb:
                k += 1
                if i == n:
                    print('密码'+str(mmlb[k]))
    else:
        break
#代码结束
for i in range(len(yhlb)):
    print("用户名{:6}密码{:6}".format(yhlb[i], mmlb[i]))