循环统计数字及图书管理系统

用循环统计出给定数据中，每种数字，分别出现了多少次

[3, 5, 2, 7, 2, 6, 4, 4, 2, 6, 7, 9, 2]

num = [3,5,2,7,2,6,4,4,2,6,7,9,2]
numq = []
for i in num:
    if i in numq:
        continue
    b = 0
    numq.append(i)
    for a in range(len(num)):     
        if i == num[a]:
            b += 1
    print("数字{}共出现{}次".format(i,b))

图书管理系统

def search():
    for i in range(0,len(l1)):
        print(l1[i],l2[i],l3[i],l4[i])
def increase():
    l1.append(input("请输入ISBN："))
    l2.append(input("请输入书名："))
    l3.append(input("请输出版社："))
    l4.append(input("请输入年份："))
    print("\n保存成功")
def delete():
    print("请输入要删除的ISBN：",end="")
    q = input()
    if q in l1:
        w = l1.index(q)
        del l1[w]
        del l2[w]
        del l3[w]
        del l4[w]
        print("\n删除成功")
    else:
        print("\n无此书目\n")
print("================\n欢迎使用图书管理系统\n================")
l1 = ["ISBN","9787111544937","9787111128069"]
l2 = ["书名","深入理解计算机系统","C程序设计语言"]
l3 = ["出版社","机械工业出版社","机械工业出版社"]
l4 = ["出版年份","2016","2014"]
while True:
    print("1.查询图书","  2.新增图书","  3.删除图书","  4.退出")
    print("请选择：",end="")
    ch = int(input())
    if ch == 1:
        search()
    elif ch == 2:
        increase()
    elif ch == 3:
        delete()

饭卡充值系统

def inquire():
    id = int(input("请输入卡号："))
    if id in card:
        b = card.index(id)
        print("【查询结果】\n卡号：{}\n余额：{}元\n".format(card[b],money[b]))
    else:
        print("查无此卡\n")
    
def recharge():
    c = int(input("请输入卡号："))
    d = int(input("充值金额："))
    if c in card:
        e = card.index(c)
        d = d + money[e]
        money[e] = d
    else:
        card.append(c)
        money.append(d)        
    print("充值成功，卡号{}余额{}元\n".format(c,d))
        
        
print("=======================\n欢迎使用饭卡充值管理系统\n=======================")
card = []
money = []
while True:
    a = int(input("请选择[1.查询 2.充值 3.退出]"))
    if a == 1:
        inquire()
    elif a == 2:
        recharge()
    else:
        break