案例ATM

#=========================================
print("ATM案例".center(60,"*"))
"""
0退出
1登录
2转账
3查询
4提现
5注册
"""
def quit():
    print("欢迎下次使用")
def login():
    print("登录功能")
def transfer():
    print("转账功能")
def check_balance():
    print("查询功能")
def withdraw():
    print("提现功能")
def register():
    print("注册功能")
dic={
    "0":("退出",quit),
    "1":("登录",login),
    "2":("转账",transfer),
    "3":("查询",check_balance),
    "4":("提现",withdraw),
    "5":("注册",register)
}
while True:
    for i in dic:
        print("{}:{}".format(i,dic[i][0]).center(60," "))
    cmd=input("输入操作的序号：").strip()
    if not cmd.isdigit():
        print("小朋友，请输入数字序号！")
    if cmd in dic:
       dic[cmd][1]()
    else:
        print("你输入的命令不存在")

# 函数嵌套
# 1.函数的嵌套调用：在调用一个函数的过程中又调用另一个函数
def max2(x,y):
    if x>y:
        return x
    else :
        return y
def max4(a,b,c,d):
    res1=max2(a,b)
    res2=max2(res1,c)
    res3=max2(res2,d)
    return res3
res=max4(11,12,23,44)
print(res)
# 2.函数的嵌套定义：在函数内定义其他函数
def f1():
    def f2():
        pass
# =================求圆的周长和面积案例==============
print("求圆的周长和面积案例".center(60,"="))
def circle(r,count=0):
    from math import pi
    def length(r):
        return 2*pi*r
    def area(r):
        return length(r)
    if count==0:
        return 2*pi*r
    if count==1:
        return area(r)
res=circle(2,1)
print(res)